TWIN CRYSTAL MONOCHROMATOR X-ray Gun Systemuhv.cheme.cmu.edu/manuals/thermovg.monoxraysource.pdf ·...

TWIN CRYSTALMONOCHROMATORX-ray Gun System

Operating Manual

Document Number HA030012

Issue 4 (11/00)

Twin Crystal Monochromator System 2 Issue 4

Thermo VG Scientific is based at East Grinstead, West Sussex, UK and manufactures and markets a widerange of surface analysis/surface science equipment, including:

- Analysers ARUPS, SIMS, CLAM2, CLAM4 and VG100AX- Electron Guns LEG32, LEG41, LEG62, LEG63, LEG200 and FEG1000- Ion Guns AG5000, EX03 and EX05.- RHEED Gun LEG110S.- X-ray Sources Mono, Twin Anode and High Power- UV Sources UV Lamps and Polarizers.- Optics RVL fixed and retractable- Additional equipment K-cells, Transfer vessels, Crystal cleaver, Gas cells, P8 probe, Evaporator etc.

Thermo VG Scientific produce integrated surface analysis systems including the:-- SIGMA PROBE- THETA PROBE- ESCALAB 250- MICROLAB 350.- MULTILAB RANGE.

This range of products allows the following techniques to be performed:AES, XPS, UPS, LEELS, LEED, RHEED, SIMS, SNMS, ISS (LEIS) and ARUPS.

Also available from Thermo VG Scientific are instruments for electron microscopy preparation from thePOLARON range, including:

- Carbon and Sputter Coaters- Plasma Reactor for ashing and etching- High vacuum bench top evaporators- Cryo Transfer Systems- Critical Point Dryers

For further information regarding any of the above products, contact your local representative or directly to:Thermo VG ScientificThe Birches Industrial EstateImberhorne LaneEast GrinsteadWest Sussex Tel: +44 (0) 1342 327211RH19 1UB, ENGLAND Fax: +44 (0) 1342 324613 / 315074Email: [email protected]://www.vgscientific.com

________________________________________________________________ ______

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HA030012 Contents

Issue 4 3 Twin Crystal Monochromator System

1 Contents1.1 Manual Layout

This Operating Manual is divided up into the following major section, each chapter dealing withspecific topics, as follows:

Chapter 1 - Contents

Chapter 2 - Health and SafetyGeneral section which applies to all Thermo VG Scientific products detailing the veryimportant issues of Health and Safety applicable when using surface analysis equipment.

Chapter 3 - IntroductionIntroduces this manual.

Chapter 4 - General DescriptionIdentifies each of the equipment items and provides an overview of their functions and howthey work.

Chapter 5 - InstallationInstructions on how this Instrument should be installed and the connections which should bemade between the equipment items.

Chapter 6 - OperationInstructions on how to start-up and run the instrument.

Chapter 7 - MaintenanceInstructions on how to check the system is functioning correctly, and how to changeconsumable items. Details of appropriate Spare parts.

Chapter 8 - Fault FindingInformation on how to identify faults in the system and how to rectify these faults.

Chapter 9 - AppendixCopies of Thermo VG Scientific standard forms to be used if equipment has to be returned tothe factory.

Chapter 10 - Index

Chapter 11 - NotesBlank pages for entering notes, etc

1.2 Copyright Notice© 2000 by Thermo VG Scientific, all rights reserved.

Information in this document is subject to change without notice and does not represent acommitment on the part of Thermo VG Scientific. No part of this document may be copied ordistributed, transmitted, transcribed, stored in a retrieval system or translated into any human orcomputer language, in any form or by any means electronic, mechanical, magnetic, manual orotherwise, or disclosed to third parties without the express written permission of Thermo VGScientific, The Birches Industrial Estate, Imberhorne Lane, East Grinstead, West Sussex, RH191UB, England.

Contents HA030012


1.3 Chapter ContentsChapter 1 - Contents ................................................................................................ 3

1.1 Manual Layout ................................................................................ 31.2 Copyright Notice ............................................................................. 31.3 Chapter Contents ........................................................................... 41.4 Illustrations ..................................................................................... 61.5 Tables ............................................................................................ 61.6 Appendix Contents ......................................................................... 6

Chapter 2 - Health and Safety ................................................................................. 72.1 Control of Substances Hazardous to Health (COSHH) ................. 72.2 Safety Policy ................................................................................... 72.3 Conformity ...................................................................................... 72.4 Servicing ........................................................................................ 82.4.1 Disclaimer ............................................................................... 82.4.2 Operators and Service Engineers .......................................... 82.5 Hazard Signals and Signs .............................................................. 82.5.1 Hazard Signal Words ............................................................. 82.5.2 Hazard Labels used on Equipment ........................................ 82.5.3 Warning Labels used in Equipment Manuals ......................... 92.5.4 Instrument Functionality Signs ............................................... 92.5.5 Serious Damage to Instruments ............................................. 102.5.6 Hazard to Operator ................................................................. 102.6 Risk Analysis .................................................................................. 102.6.1 Personal Operational Risks .................................................... 102.6.2 Hazardous Materials ............................................................... 112.7 Good Working Practices ................................................................ 122.8 Monochromated, X-ray Specific Safety Hazards ........................... 132.8.1 Safety Interlocks ..................................................................... 132.8.2 Radiation Hazards .................................................................. 132.8.3 Water ...................................................................................... 132.8.4 Degassing Procedure ............................................................. 13

Chapter 3 - Introduction............................................................................................ 143.1 Contact Information ........................................................................ 143.2 Return of Goods ............................................................................. 14

Chapter 4 - Description ............................................................................................ 154.1 Equipment ...................................................................................... 154.1.1 Optional Items ........................................................................ 154.2 Overview ........................................................................................ 164.3 Technical Specification .................................................................. 164.3.1 Monochromator X-ray Gun Specification ............................... 164.3.2 Model 8706 Power Supply Unit ............................................... 164.3.3 Model 8732 Control Unit Specification ................................... 164.3.4 Model T-182/T-184 Power Supply and Water Control Unit .... 174.4 Monochromator System.................................................................. 174.4.1 Crystal Manipulator Assembly ................................................ 174.4.2 Aluminium Window ................................................................. 184.4.3 Crystals ................................................................................... 184.4.4 Monochromator X-ray Source ................................................. 194.4.5 E4870PR4 Water Chiller Recirculator .................................... 204.5 Interlocks ........................................................................................ 204.6 Model 8732 Control Unit ................................................................ 214.6.1 Model 8732 Control Unit, Front Panel Controls ...................... 214.6.2 Model 8732 Control Unit, Rear Panel Connections ................ 224.7 Model 8706 Power Supply ............................................................. 234.7.1 Model 8706 Power Supply, Front Panel Controls ................... 234.7.2 Model 8706 Power Supply, Rear Panel Connections ............. 244.8 Model T-182 or T-184 Power Supply ............................................. 254.8.1 Model T-182/T-184 Power Supply, Front Panel Controls ....... 254.8.2 Model T-182/T-184 Power Supply, Rear Panel Connections . 264.9 Flow Switch Assembly .................................................................... 26

HA030012 Contents


Chapter 5 - Installation ............................................................................................ 275.1 Unpacking Checklist ...................................................................... 275.1.1 Preparation ............................................................................. 275.1.2 Installation General ................................................................ 275.2 Hardware Installation ..................................................................... 285.3 Pipework ........................................................................................ 295.3.1 Differential Pumping ............................................................... 295.4 Evacuation / Bakeout ..................................................................... 305.4.1 Bakeout .................................................................................. 305.4.2 System / Component Bakeout ............................................... 315.4.3 Fit Crystal Manipulator ............................................................ 325.5 System Wiring ................................................................................ 325.5.1 Cable Connections ................................................................. 33

Chapter 6 - Operation .............................................................................................. 346.1 Procedures Notes .......................................................................... 346.1.1 Cooling Water ........................................................................ 346.1.2 Radiation Testing ................................................................... 356.2 Degassing the Monochromator....................................................... 356.3 Aligning the Monochromator .......................................................... 386.3.1 Check the Calibration of the Analyser .................................... 386.3.2 Course Adjustment of the Monochromator ............................ 386.3.3 Fine Adjustment of the Monochromator ................................. 396.4 Monochromator Start Up ............................................................... 406.5 Shut Down ..................................................................................... 40

Chapter 7 - Maintenance .......................................................................................... 417.1 Maintenance - General Notes ......................................................... 417.2 Dual Crystal Manipulator ................................................................ 427.2.1 Micrometer Adjusters ............................................................. 427.2.2 Removing the Manipulator ..................................................... 427.2.3 Fitting the Manipulator ............................................................ 427.3 Aluminium Window Replacement .................................................. 437.4 Lower Leg Assembly....................................................................... 447.4.1 Replacing the Mono Gun Anode ............................................ 447.4.2 Replacing the Electron Gun Filament ..................................... 457.5 Electronic Units .............................................................................. 467.5.1 Model 8706 Replacement ...................................................... 467.5.2 Model 8732 Replacement ....................................................... 467.6 E4870PR4 Water Chiller Maintenance .......................................... 477.7 Spare Parts ..................................................................................... 47

Chapter 8 - Fault Finding ......................................................................................... 488.1 Trouble Shooting / Fault Finding .................................................... 488.2 Fault Prevention ............................................................................. 49

Chapter 9 - Appendix ............................................................................................... 50

Chapter 10 - Index .................................................................................................... 53

Chapter 11 - Notes ................................................................................................... 54

Contents HA030012


1.4 IllustrationsFigure 2.1 - Hazard Warning Symbols ....................................................................... 8Figure 2.2 - International Warning Symbols ............................................................... 9Figure 2.3 - Warning Notices ..................................................................................... 9Figure 2.4 - Typical Caution Warnings, as shown in this Manual ............................... 9Figure 2.5 - Typical Caution Warnings, as shown in this Manual ............................... 10Figure 2.6 - Typical Warnings, as shown in this Manual ............................................ 10Figure 4.1 - Monochromator System .......................................................................... 17Figure 4.2 - Crystal Manipulator Assembly.................................................................. 17Figure 4.3 - Aluminium Window and Rotary Drive ..................................................... 18Figure 4.4 - X-ray Source (Earthed Anode) ................................................................ 19Figure 4.5 - E4870PR4 Water Chiller Recirculator .................................................... 20Figure 4.6 - Model 8732 Control Unit ......................................................................... 21Figure 4.7 - Model 8732 Control Unit, Front Panel Controls ...................................... 21Figure 4.8 - Model 8732 Control Unit, Rear Panel Connections ................................ 22Figure 4.9 - Model 8706 Control Unit ......................................................................... 23Figure 4.10 - Model 8706 Power Supply, Front Panel Controls ................................. 23Figure 4.11 - Model 8706 Power Supply, Rear Panel Connections ........................... 24Figure 4.12 - Model T-182 Power Supply and Water Control Unit ............................. 25Figure 4.13 - Model T-182/T-184 Power Supply, Front Panel Controls ..................... 25Figure 4.14 - Model T-182/T-184 Power Supply, Rear Panel Connections ............... 26Figure 4-15 - Flow Switch Assembly (240v) ................................................................ 27Figure 5.1 - Pipework Layout....................................................................................... 29Figure 5.2 - Water Connections to the Electron Gun ................................................. 29Figure 5.3 - System Connections (T182 Supply Fitted) .............................................. 33Figure 6.1 - Layout of Model 8732 X-ray Controller ................................................... 37Figure 7.1 - Micrometer Adjusters............................................................................... 42Figure 7.2 - The Aluminium Mono Window and Rotary Drive .................................... 43Figure 7.3 - Separate Anode Assembly ..................................................................... 44Figure 7.4 - Monochromator Electron Gun.................................................................. 45Figure 7.5 - Filter Position on the Water Box ............................................................. 47

1.5 TablesTable 2.1 - Personal Operational Risks ...................................................................... 10Table 4.1 - Electrical Connections to the Electron Gun .............................................. 19Table 4.2 - Model 8732 Front Panel Control Descriptions ......................................... 21Table 4.3 - Model 8732 Rear Panel Connection Descriptions ................................... 22Table 4.4 - Model 8706 Front Panel Control Descriptions ......................................... 23Table 4.5 - Model 8706Rear Panel Connection Descriptions .................................... 24Table 4.6 - Model T-182/T-184 Front Panel Control Descriptions ............................. 25Table 4.7 - Model T-182/T-184 Rear Panel Connection Descriptions ....................... 26Table 6.1 - Model 8706 Settings ................................................................................ 37Table 7.1 - Model 8706 Link and Capacitor Settings .................................................. 46Table 7.2 - Spare Parts .............................................................................................. 47Table 8.1 - Trouble Shooting ...................................................................................... 48Table 8.2 - Fault Prevention ....................................................................................... 49

1.6 Appendix ContentsAppendix 1 - Form CC011 - Returned goods, Health & Safety Clearance ................ 50Appendix 2 - Form HK000102A - Warranty Claim, Repair & Returns Procedure ...... 51Appendix 3 - Form CC009 - Returned Equipment Report ......................................... 52

HA030012 Health and Safety


2 Health and SafetySafety is very important when using any instrumentation and this chapter should be read by allusers of our equipment.

This section of the Manual applies to all surface analysis equipment and instrumentation suppliedby Thermo VG Scientific not just the particular instrument for which the manual refers.

Included in this chapter are details on warning notations, good working practices and information onEuropean Community (EC) legislation regarding “Control Of Substances Hazardous to Health”(COSHH) and risk analysis.

2.1 Control of Substances Hazardous to Health (COSHH)The E.C. legislation regarding the “Control of Substances Hazardous to Health” requires ThermoVG Scientific to monitor and assess every substance entering or leaving their premises.Consequently any returned goods of whatever nature must be accompanied by a declaration formavailable from Thermo VG Scientific, reference number CC011 (see appendix forms). Without thisdeclaration Thermo VG Scientific reserves the right not to handle the substance/item. Also inaccordance with E.C. regulations we will supply on request hazard data sheets for substances usedin our instruments.

2.2 Safety PolicyThis section contains important information relating to all health and safety aspects of theequipment. As such it should be read, and understood, by all personnel using the instrumentwhether as an operator or in a service capacity.

Thermo VG Scientific is committed to providing a safe working environment for its employees andthose that use it's equipment and conducts its business responsibly, and in a manner designed toprotect the health and safety of its customers, employees and the public at large. It also seeks tominimise any adverse effects that its activities may have on the environment.

Thermo VG Scientific regularly reviews its operations to make environmental, health and safetyimprovements in line with UK and European Community legislation.

The equipment has been designed for use on surface analysis systems with the instrumentmounted on a vacuum chamber and the electronics unit mounted on an adjacent electronics rack.All hardware and electronic power supplies required to carry out the operation of the instrument isprovided. Thermo VG Scientific cannot be held responsible for any damage, injury or consequentialloss arising from the use of its equipment for any other purposes, or any unauthorised modificationsmade to the equipment.

All service work carried out on the equipment should only be undertaken by suitably qualifiedpersonnel. Thermo VG Scientific is not liable for any damage, injury or consequential loss resultingfrom servicing by unqualified personnel. Thermo VG Scientific will also not be liable for damage,injury or consequential loss resulting from incorrect operation of the instrument or modification ofthe instrument.

2.3 ConformityThis instrument is supplied in a form that complies with the protection requirements of the ECElectromagnetic Compatibility Directive 89/336/EEC and the essential health and safetyrequirements of the low voltage directive 72/23/EEC both as amended by 92/31/EEC. Anymodifications to the equipment, including electronics or cable layout may affect the compliance withthese directives.

The electronic units will meet the following standards when correctly fitted in apparatus.

BSEN610101-1 Safety requirements for electrical equipment for measurement, control andlaboratory use.

BSEN50081-1 General emission standard.

BSEN50082-2 General immunity standard.

Health and Safety HA030012


2.4 Servicing

2.4.1 DisclaimerAll service work on the equipment should be carried out by qualified personnel. Thermo VGScientific cannot be liable for damage, injury or consequential loss resulting from servicing byunqualified personnel. Thermo VG Scientific will also not be liable for damage, injury orconsequential loss resulting from incorrect operation of the instrument or modification of theinstrument.

2.4.2 Operators and Service EngineersA normal operator of the equipment will not be trained in or qualified for service work on theequipment and may cause a hazard to himself/herself or others if such work is attempted.Operators should therefore restrict themselves to the normal operation of the equipment and notattempt to remove covers from the electronic equipment or dismantle the instruments.

Service Engineers who are suitably trained to assess and isolate electrical, mechanical and vacuumhazards should be the only personnel who access the equipment.

2.5 Hazard Signals and Signs

2.5.1 Hazard Signal WordsThe standard three hazard signal words are defined as follows:

◆ DANGER - imminently hazardous situation or unsafe practice that, if not avoided, willresult in death or severe injury.

◆ WARNING - potentially hazardous situation or unsafe practice that, if not avoided, couldresult in death or severe injury.

◆ CAUTION - potentially hazardous situation or unsafe practice that, if not avoided, mayresult in minor or moderate injury or damage to equipment.

2.5.2 Hazard Labels used on EquipmentSeveral hazard symbols may be found on the equipment, they are shown below with their meaning:

Caution, risk of electric shockCaution (refer to accompanying documents)

Easily touched higher temperature parts Warning, risk of electric shock

Figure 2.1 - Hazard Warning Symbols



2.5.3 Warning Labels used in Equipment ManualsThe international warning signs used in equipment manuals as shown in Figure 2.2.

Figure 2.2 - International Warning Symbols

Where appropriate these are used when a specific identifiable risk is involved in either using ormaintaining the instrument. These take the form of warning triangles or signs with a graphicaldescription of the hazard.

In the case of voltage warnings these often appear on the actual item of concern in variouslanguages as shown in Figure 2.3.

Figure 2.3 - Warning Notices

2.5.4 Instrument Functionality Signs

CAUTIONDo not allow the Emission to rise above 4.2 Amps.

Figure 2.4 - Typical Caution Warning as shown in this Manual

This typical sign applies to cautions where there is a risk to the functionality of equipment due toincorrect operation. These cautions or warnings will be contained in a box and be accompanied bya circular warning symbol as shown in Figure 2.4.



2.5.5 Serious Damage to Instruments

CAUTIONOperating this X-ray source at over 800W (20Kv, 40mA)

can seriously damage the anode coating.

Figure 2.5 - Typical Caution Warning as shown in this Manual

This typical caution sign is used where serious damage will be caused by incorrect operation ofinstrumentation. They will follow the same form as functionality warnings but with a triangularwarning symbol as shown in Figure 2.5.

2.5.6 Hazard to Operator

WARNINGHAZARD TO HEALTH!

Potentially lethal voltages are used in this equipment. Before making / breaking connections to the equipment, ensure power is off

and that it is safe to proceed.

Figure 2.6 - Typical Warning as shown in this Manual

These warnings will generally occur in relevant installation and maintaining sections where thereexists a potential hazard to the engineer working on the instrument. They will take the form of thetriangular warning symbol accompanied by an international warning sign and bold type letteringbeginning with “WARNING-HAZARD TO HEALTH!” as shown in Figure 2.6.

2.6 Risk Analysis

2.6.1 Personal Operational RisksThe following is a list of tasks carried out by both the operator and service engineer whererecognised risks have been observed, listed is the personnel protection equipment (PPE) which issuggested for use for various tasks on any surface analysis equipment and systems:

Task Carried out by Nature of Hazard Recommended PPECleaning of parts /samples withisopropanol (IPA)

Operator / Serviceengineer

Splash hazard toeyes, drying of skin

Protective goggles,protective gloves.

Lifting of monochamber

Service engineer Heavy lift. A mechanical lifting hoistshould also be consideredfor this function.

Handling Thoriacoated filaments

Service engineer Ingestion Protective gloves and facemask should be worn.

Lifting of Heavy Items Service engineer Dropping on foot. Protective footware.

Table 2.1 - Personal Operational Risks



2.6.2 Hazardous Materials◆ Thoria Coated Filaments

The ion gauge filaments, most “LEG” guns, and most X-Ray filaments possess a coating,which is 85% Thorium Oxide and 15% Thorium Nitrate which are both radioactive. It isestimated that each filament has a mass of 0.016 g. Local regulations and recommendationson handling and disposal of this material should be abided by, but as a minimum skin contactand inhalation should be avoided.

◆ Isopropanol (IPA)For certain service tasks isopropanol is suggested for cleaning components before use in thevacuum system. It should be noted that isopropanol is a flammable liquid and as such shouldnot be used on hot surfaces, for instance which might exist after the bakeout of a system. Inaddition it is recommended that protective gloves are worn when using isopropanol.

◆ Liquid NitrogenOnly operators with experience in the safe handling of liquid nitrogen should use theequipment under these conditions. Thermally insulated gloves and goggles should be worn atall times when handling and using liquid nitrogen.

◆ Nitrogen, Argon and Helium Gas SuppliesSystems may use nitrogen for venting an airlock and/or the main vacuum system, argon foruse with the “EX03”, “EX05”, “AG5000” and ION guns and helium for use with the “UVLamp”. The customer is responsible for maintaining the supply to the system. This supplyshould be regulated and kept to the lowest pressure and flow rate as is practical to minimisethe effects of any leaks.

◆ Hazardous GasesThermo VG Scientific has no control over the gases used within the system. It is thereforeviewed as the customers responsibility to assess the hazards involved and take appropriateprecautions when using explosive, toxic or corrosive gases or gases which may result inhazardous products as a result of a chemical reaction.



2.7 Good Working PracticesIt is essential that good hygienic working practices are adopted at all times especially in an ultrahigh vacuum or cleanroom environment and are generally of the “Common sense” type. Somesimple good practice rules are:

◆ If in doubt don't.

◆ If in doubt ask.

◆ When handling solvents wear face mask, gloves, apron and work only in a wellventilated area.

◆ Mop up any spillages immediately.

◆ When handling or decanting mineral oils wear protective clothing.

◆ Aerosols of mineral oils, such as that produced by gas ballasting, can prove to behazardous and an exhaust is recommended.

◆ Before attempting to service electrical apparatus, isolate from the mains.

◆ Treat all unknown substances as hazardous.

◆ Dispose of substances in an appropriate manner.

◆ Use the correct tool for the job.

◆ Keep a straight back and bend from the knees when lifting heavy objects.

◆ Wear protective clothing when using liquid nitrogen.

◆ Affix pressurised gas cylinders firmly to walls or racks. Use the correct regulating valveson gas cylinders and always transport cylinders using the appropriate specialist trolley.

◆ Obey safety regulations regarding lifts, hoists and machine tools.

◆ Always keep protective screens or lead-glass viewports on if using an X-ray source.

◆ Always make sure you understand a procedure well before attempting it for the firsttime.



2.8 Monochromated X-ray Specific Safety HazardsThe following Safety Hazards are specific to the range of Monochromated X-ray sources.


The Model 8732 Control Unit used to control the X-ray Gun produces HAZARDOUS VOLTAGE OUTPUTS of up to 12Kv.

The power supplies are fitted with earth terminals on the rear panels. These earth terminals mustbe connected by an earth braid to a suitable earth point.

It is essential that this earth braid be securely attached to the X-ray Gun flange and to the Model8706 Glassman Unit before connecting the power to the power supply. All cables MUST beconnected before applying power.

2.8.1 Safety InterlocksThe Model 8706 Power Supply Unit and the Model 8732 Control Unit incorporate interlocks toprevent the high voltage being switched on unless ALL the high voltage cables are connectedbetween the power supply unit sockets and the X-ray source. Reduced cooling water flow rate willactivate the water interlock.

2.8.2 Radiation HazardsThe Monochromated X-ray Source used for XPS applications generates X-ray radiation whenelectrons are emitted from the filament and strike the coated anode which is at a potential of up to+10kV. To protect the user from X-ray radiation, the use of lead glass view ports is essential. Thisrisk can be eliminated by fitting, if not already fitted, lead glass over the windows. These lead glasswindows are available from Thermo VG Scientific. However, the end user must satisfy himself thereare no other leakage from the system. If in doubt, an expert should be consulted.

2.8.3 WaterPrior to switching on any power check that all water connections are secure and no leaks arevisible. Ensure system is totally dry after connecting water lines to the X-ray source.

Ideally the X-ray should be operated between 150C and 200C. The water inlet temperature shouldnot be cooler than the room temperature otherwise condensation will form, however the inlettemperature should not exceed 250C.

2.8.4 Degassing ProcedureIn order to carry out the degassing procedure with the I-8732 X-ray controller a level of electricalcompetence is required. This level of competence should be either through qualifications, experienceor training. The requirement for this competence is due the fact that the unit will have to be isolatedfrom the incoming supply and covers will have to be removed which will expose the engineer to lethalvoltages. (10kV at up to 30 mAmps)

The normal precautions for working with high voltages should then be put in place. i.e. A rubber matshould be provided for the engineer to stand on, The area should be barricaded off and suitablewarning signs put in place. Other people should be in the vicinity to provide assistance in the event ofan accident.

The potentiometers that have to be adjusted are at a high potential. In order for these to be adjustedsafely their shaft have been extended through the perspex top cover using insulating material.However care should still be taken when making the adjustments due to the High voltages involved

IF YOU ARE IN ANY DOUBT REGARDING THIS PROCEDURE, NO ATTEMPT SHOULD BEMADE TO CARRY THEM OUT. INSTEAD CONTACT YOUR LOCAL THERMO VG SCIENTIFICREPRESENTATIVE FOR ASSISTANCE.

Introduction HA030012


3 IntroductionThis manual is intended for all users of the Monochromated X-ray Sources manufactured byThermo VG Scientific and provides information on the installation, operation and maintenance ofthe instrument.

Please note that the servicing and maintenance procedures should only be carried out by qualifiedservice personnel and it is essential that all users should read the Health and Safety section of thismanual.

This manual does not provide a description of the principles and the techniques used in surfacescience. If information is required, we recommend the following standard texts:-

Practical Surface Analysis, volume 1 and 2, by D.Briggs and M.P.Seah,publisher - Wiley, ISBN 0-471-92081-9.

Methods of Surface Analysis, edited by J.M.Walls,publisher - Cambridge University Press. ISBN 0-521-30564-0.

Modern Techniques of Surface Science, by D.P.Woodruff and T.A.Delchar,publisher - Cambridge University Press. ISBN 0-521-35719-5

For ease of identification the names of controls, indicators, displays and modes of operation aretypographically distinct from the ordinary text of this manual. These distinctions are as follows:

(a) Controls, indicators and displays are presented in upper-case, bold, ARIAL typefacethroughout; for example IGNITE lamp, PROGRAM button.

(b) Notes and comments are presented in red italic text.

3.1 Contact InformationWe hope that this manual effectively assists you in the running of this instrument. If you have anyquestions or comments regarding this equipment and manual please do not hesitate to contact yourlocal service representative or to Thermo VG Scientific directly using the following contactinformation:Customer Support DepartmentThermo VG ScientificThe Birches Industrial EstateImberhorne Lane Tel: + 44 (0) 1342-310321East Grinstead Fax: + 44 (0) 1342-315074West Sussex Email: [email protected] 1UB UK web: http://www.vgscientific.com

3.2 Return of GoodsIf goods are to be returned to Thermo VG Scientific for repair or servicing the customer shouldcontact their local distributor or the factory direct before shipment. A "Returns AuthorisationNumber" should be obtained in advance of any shipment. This number is to be clearly marked onthe outside of the shipment. Complete the returned equipment report form, number CC009 with asmuch detail as possible and return with the goods.

All returned goods are to be accompanied by a completed "Returned Goods Health and SafetyClearance" form CC011 attached to the outside of the package (to be accessible without openingthe package) and a copy of the forms should be faxed in advance to the factory.

When goods are to be returned under warranty refer to the “Warranty Claim, Repair and ReturnsProcedure” form number HK000102ACopies of all these three forms can be found in the appendix of this manual. Photocopies of theseforms can be used.

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HA030012 Description


4 Description4.1 Equipment

Each Monochromator X-ray System when supplied as a package, includes the monochromatorchamber with crystals, crystal manipulator, electron gun and anode assembly. Rack mountingdedicated Electronics units and Water Control unit, chamber mounting kit any ancillary unitstogether with the required cable assemblies and operation manual. Items can be ordered as a fullpackage or separately against the following numbers:

Monochromator Chamber Body - 933-03-002.

Crystal Manipulator with Adjusters - 933-01-006.Crystals (2 off) - 933-01-043.Sealing Foil Window - 933-01-048.Lower Leg (833-05-017) with Anode Assy (833-05-016) & Electron Gun(I-8856-2).

Electronics Model 8732 High Power X-ray Gun Control Unit.Model 8706 High Power X-ray Gun Power Supply Unit.Model T182-70-4 Power Supply and Water Control Unit (240V) or Model T182-70-4 Power Supply and Water Control Unit (110V).

Miscellaneous Flow Switch AssemblyCable Assemblies.Mounting kit includes bolts, nuts, gaskets etc. - XR501.Wiring Diagrams (on request).Operation Manual HA030012.

4.1.1 Optional itemsThe components listed below which are manufactured by Thermo VG Scientific are some of theitems available for use with the Monochromator X-ray Source.

E4870PR4 Water Chiller package providing adequate recycled cooling water for the X-raySource. Fully compatible with the above package. (For full details for theoperation of this unit refer to Operation Manual HA080002).

Lead Glass WindowsA range of lead glass windows, to clamp over plain glass Viewports on vacuumsystems not equipped with lead glass Viewports.

XR050 Lead Glass window to clamp over a VPZ38 Viewport.




Description HA030012


4.2 OverviewThe monochromator is a twin crystal Rowland geometry focussing X-ray source (earthed anode)with a water cooled SSI gun Type I-8856. The source and anode are powered from a Model 8706Glassman high voltage supply and X-ray controller Model 8732. (see Figure 4.1).

The X-ray beam from the anode passes through a hinged port into the monochromator chamberand is diffracted and focussed by a pair of crystals onto the target. An aluminium window assemblyis fitted to the base of the monochromator chamber. Using the rotary drive at the side of thechamber the window can be positioned over the output port of the monochromator or stand uprightout of the X-ray beam. The window is normally positioned across the monochromator to reducebackground counts caused by the transmission of electrons from the X-ray source electron gun tothe sample. Note that when the system is to be vented, the window must be placed in the uprightposition to avoid damage by the sudden rush of air.

An ion pump is fitted to the monochromator chamber to differentially pump the chamber.

The Anode is water-cooled and the power supply is interlocked to the flow rate and controlledthrough the Model T-182/T-184 Unit.

When using any of the Thermo VG Scientific range of X-ray equipment it is critical to control thetemperature of the water flowing through the X-ray anode. A recommended operating watertemperature is between 15OC and 20OC. A suitable piece of equipment to achieve and control thistemperature range is the E4870PR4 Chiller Re-circulating Heater/Chiller. Increasing pressure onnatural resources has resulted in many countries restricting the use of water running to waste forcooling of instrumentation. The E4870PR4 water recirculating heater/chillers is recommended foropen and closed loop water circuit applications, offering simplicity and quiet operation.

The Unit is designed to be incorporated in a UHV Surface Analysis system. The monochromator ismounted on a 114mm outside diameter chamber port.

4.3 Technical Specification 4.3.1 Monochromated X-ray Gun Specification

Type Water cooled single anode, twin quartz crystal on 0.5 metre Rowlandcircle.

Anode Material Aluminium.X-Ray Energy Al Kα 1486.6 eV.Operational Voltage 10keV.Power Dissipation Factory set to 15W, 45W, 100W, 200W (max).Spatial Resolution Nominally 150µm, 250µm, 400µm, 1000µm.Safety Interlocks High voltage, coolant, vacuum and mechanical interlocks.

4.3.2 Model 8706 Power Supply SpecificationInput 115V at 50/60 Hz.Output voltage 0-10kV Negative polarityOutput current 0-30mA.19” Rack mounting 2U high x 420mm deepWeight 8 Kilogram (18lb.)

4.3.3 Model 8732 Control Unit SpecificationAnode HV 0 to 20kVSingle voltage 115V at 50/60 Hz.Beam Current 0 to 40mA emission and 0 to 20mA leakage.19” Rack mounting 4U high x 500 mm deepWeight 18.5 Kilogram (41.0 lb.)



4.3.4 Model T-182/T-184 Power Supply SpecificationInput 200/260V at 50 Hz. (T-182) or (100/120V at 60 Hz. (T-184)Output voltage 110V ±5% (T-182).

120V ±3% (T-184).19” Rack mounting 6U high x 540 mm deepWeight 46 Kilogram (102 lb.)

4.4 Monochromator SystemThe Monochromator X-ray system (Figure 4.1) is mounted on a specially designed MonochromatorChamber which has four principle components.

(a) Crystal Manipulator Assembly.(b) Crystals.(c) Aluminium Window.(d) Lower Leg with Electron Gun and Anode assembly.

Figure 4.1 – Monochromator System

4.4.1 Crystal Manipulator AssemblyThe Crystal manipulator assembly (Figure 4.2) is mounted at the top of the monochromatorchamber and provides facilities for the operator to adjust the position of each crystal to providebest response from the associated analyser. Three micrometers push against each crystalmounting plate that is secured to the top of the monochromator by three springs. Thisarrangement gives extremely fine control of the reflected radiation. The X-rays incident on thecrystals are diffracted and focussed into a monochromatic spot on the sample in the mainchamber.

Figure 4.2 Crystal Manipulator Assembly



4.4.2 Aluminium WindowThe aluminium window (Figure 4.3) is situated between the crystals and the sample. It consistsof a thin, <1um, aluminium sheet supported by a wire framework and mounted on a rotatabledrive. This allows the window to be opened (turning the drive anti-clockwise to a stop) or closed(turning the drive clockwise to a second stop). The window absorbs electrons that wouldotherwise affect an insulating sample. Closing the window also reduces the background countrate on conductive samples. A side effect is that it attenuates the X-ray flux by around 10 per-cent. The window is closed when analysing insulating samples.

Ensure it is open when the analysis chamber is being vented to avoid any damage to thealuminium sheet.

Figure 4.3 Aluminium Window and Rotary Drive

4.4.3 CrystalsAl K alpha x-rays from the anode are diffracted by the twin crystals onto the sample. The shapeof the quartz crystals is such that the small area of x-ray generation on the anode is focussedonto the sample. The Bragg diffraction from the crystal lattice provides the energy resolution ofthe final X-ray beam.

The crystals can be individually manipulated in the dispersive and non-dispersive directions aswell as in height, via the set of 6 manipulators on the back of the manipulator assembly. Theseadjustments are made from the outside of the vacuum system while the monochromator isrunning. In addition, the position of the e-gun and anode can be moved, effectively changing theBragg angle. All of these adjustments are made at the time of installation and do not need to beroutinely changed by the operator. The only exceptions to this are slight movements of the monospot position using the dispersive and non-dispersive adjusters after a bakeout.



4.4.4 Monochromator X-ray SourceThe X-ray source, Figure 4.4, comprises an electron gun and anode housed in the lower legassembly of the monochromator. The earthed anode is mounted on a cooled support plate fittedinto a port on the side of the leg. The electron gun Type 8856 is housed in a cooled gun shield andmounted in the end port of the leg. Table 4.1 details the electrical connections to the electron gun.

Figure 4.4 - X-ray Source (Earthed Anode)

PIN DESTINATION PLAN VIEW

1 Filament

2 Pierce Voltage

3 Focus Voltage

4 Quadrupole Voltage

5 Pierce Voltage

6 Filament

7 Cathode

12

34

5

67

Table 4.1 Electrical Connections to the Electron Gun(Viewed from Outside Vacuum)



4.4.5 E4870PR4 Water Chiller RecirculatorThe E4870PR4 Chiller Re-circulating Heater/Chiller is an optional item available for both 240and 110 volt supply. An operation manual HA080002 is supplied with each unit.

The E4870PR4 unit incorporates a refrigerator compressor system that has been primarilydesigned for applications which require the cooling of equipment back to ambient temperatures.The maximum temperature range of the systems is -20OC to +60OC. The refrigerant agent usedin all units is CFC free type R134A.

Figure 4.5 – E4870PR4 Circulating Water Heater/Chiller

4.5 InterlocksSafety interlocks are incorporated in the Model 8706 Power Supply Unit and the Model 8732 ControlUnit. In the event of the required safety considerations not being met the voltage outputs from theModels 8706 and 8732 Units are inhibited.


Potentially lethal voltages are used in this equipment.Under no circumstances should interlock connections be over-ridden.

The 115V A.C output from the Model T182 is only maintained whilst the water flow interlock ismade. If the water flow stops or falls below a pre-set level the power to the Models 8706 and 8732is shut down.



4.6 Model 8732 Control UnitThe Model 8732 X-ray Gun Control Unit is designed for 19” rack mounting, it controls the filamentcurrent, X-ray source emission and the shape of the beam leaving the electron gun on the X-raysource. All inputs and outputs from the equipment are via rear mounted connectors.

Figure 4.6 – Model 8732 Control Unit

4.6.1 Model 8732 Front Panel ControlsThe controls and indicators mounted on the Model 8732 front panel are identified in Figure 4.7 anddescribed in Table 4.2.

Figure 4.7 - Model 8732 Control Unit, Front Panel Controls

CONNECTION DESCRIPTIONMETER Used to display the output selected by the METER FUNCTION switch.

METER FUNCTION The 6-position rotary switch is used to select the type of data displayed on the multi-functionMETER.

SPOT SIZEMICRONS

The 6-position rotary switch sets the beam spot size, places the beam size under the control of anexternal signal (REMOTE) and switches the beam off.

READY The orange lamp indicates that power is present and the source is in the operating condition.

PRE HEAT The orange push-button applies power to the source to condition it for use.

INTERLOCKREADY

The green lamp is lit in normal operation. It is extinguished if a panel is removed from the unit or if acover is removed from the unit or a rear panel BNC interlock connector is not closed.

LINE The white push-button controls the mains input to the unit and is lit in normal operation.

Table 4.2 - Model 8732 Front Panel Control Descriptions



4.6.2 Model 8732 Control Unit Connections

The connection points mounted on the rear panel of the Model 8732 Control Unit are describedbelow and identified in Figure 4.8 and described in Table 4.3.

LE000267A

Figure 4.8 - Model 8732 Control Unit, Rear Panel Connections.

CONNECTION DESCRIPTIONJ1 - 10kV IN -10Kv input from the Model 8706 power supply

J2 - GUN INPUT Attached cable assembly to the Electron Gun

J3 - SYSTEM INTERLOCK IN Interlock cable from the Vacuum Interlock on the Model T-182or T-184 unit.

J4 - 10 kV INT IN Interlock cable from the Model 8706 power supply

J5 - SYSTEM INTERLOCK OUT Not used

J6 - REMOTE CONNECTOR Not used

J7 - MAINS AND FUSE 3 Pin 110/120 V mains input plus 2Amp SB Fuse

J8 - LINE WIDTH CONTROL Not used

E - GROUND STUD Earth ground stud

J9 - V QUAD Not used

Table 4.3 - Model 8732 Rear Panel Connection Descriptions



4.7 Model 8706 HV Power SupplyThe Model 8706 High Voltage Power Supply (Glassman HV Unit) is designed for 19” rackmounting; it provides the HV (or EHT) power at constant voltage/current to the Model 8732 Controlunit for the small spot monochromator.

Full details of this unit can be found in the Glassman High Voltage supplies instruction manual “ERSERIES” for the model PS/ER10N30.0XX7.

Figure 4.9 – Model 8706 HV Power Supply Unit

4.7.1 Model 8706 Front Panel ControlsThe controls and indicators mounted on the Model 8706 front panel are identified in Figure 4.10 anddescribed in Table 4.4.

Figure 4.10 - Model 8706 Power Supply, Front Panel Controls

CONNECTION DESCRIPTIONHIGH VOLTAGE ON The green push-button enables the high voltage output when pressed.

This switch will not activate the high voltage if the INTERLOCK READY light on the Model8732 is not lit.The HIGH VOLTAGE ON lamp is lit when the HV ENABLE push-button is pressed (if theINTERLOCK signal is closed). If this indicator is on at the same time that the HV ENABLEsignal is present the supply will generate high voltage. If the INTERLOCK signal is open, eventemporarily, the high voltage will be disabled and the HIGH VOLTAGE ON indicator willextinguish. Once the interlock is closed the HIGH VOLTAGE ON push-button must again bepressed to restart the supply.

POWER This orange switch applies AC power to the unit when in the ON position, (marked I). Theintegral red lamp is lit when power is present.

LED The red LED is illuminated when under MILLIAMPERE controlPotentiometer A 10-turn potentiometer provides a 0-10V signal for local MILLIAMPERE

programming. Clockwise rotation increases output. A 10-turn dial isprovided to secure the settings, if desired.

CONTROLMILLIAMPERES

Meter 0-30mA meter indicates the supply is operating as a constant currentsupply with the output current determined by the local MILLIAMPERESCONTROL or I-PROGRAM signal when the adjacent LED is illuminated.

LED The red LED is illuminated when under KILOVOLT controlPotentiometer A 10-turn potentiometer provides a 0-10V signal for local KILOVOLT

programming. Clockwise rotation increases output. A 10-turn dial isprovided to secure the settings, if desired.

CONTROLKILOVOLTS

Meter 0-10kV meter indicates the supply is operating as a constant voltagesupply with the output voltage determined by the local KILOVOLTSCONTROL or V-PROGRAM signal when the adjacent LED is illuminated.

Table 4.4 - Model 8706, Front Panel Control Descriptions



4.7.2 Model 8706 Power Supply Connections

The connection points mounted on the rear panel of the Model 8706 Power Supply aredescribed below and identified in Figure 4.11 and described in Table 4.5.

LE000270A

Figure 4.11 - Model 8706 Control Unit, Rear Panel Connections.

CONNECTION DESCRIPTIONJ1 - High voltage output to the Model 8732 unit

E1 – GROUND STUD Earth ground stud

POWER ON Mains power orange indicator

J3 - Interlock cable to the Model 8732 unit

F1 - Fuse - 100/115 – 6A SB

J2 – MAINS INPUT 110/120V -3 pin mains input connector from the Model T-182 or T-184 unit1 Ground Linked to 2 and 32 Common Linked to 1 and 33 Interlock Linked to 1 and 24 V-Monitor5 V-Program Linked to 66 Local V-Control Linked to 57 I-Monitor8 I-Program Linked to 99 Local I-Control Linked to 810 Reference Linked to 1111 HV Enable Linked to 10

TB1 – Terminal Block

12 X1

Table 4.5 - Model 8732 Rear Panel Connection Descriptions



4.8 Model T-182 or T-184 Power Supply and Water Control UnitThe Model T-182 (240volt) or the Model T-184 (115volt) Power Supply and Water Control Unit isdesigned for 19” rack mounting; it provides the 110V power output to both the Model 8706 and 8732units and also to both the water booster pump and water Flow switch Monitor assembly. Thesystem and water interlocks are also controlled by this unit.

Figure 4.12 – Model T-182 Power Supply and Water Control Unit

4.8.1 Model T-182/T-184 Front Panel ControlsThe controls and indicators mounted on the Model T-182/T-184 front panel are identified in Figure4.13 and described in Table 4.6.

LE000268A

Figure 4.13 - Model T-182/T-184 Power Supply, Front Panel Controls

CONNECTION DESCRIPTIONPOWER ON A green LED indicating when there is power to the unitPUMP START This push-button switch is used to start the water pump, an integral

green indicator is illuminated when switch on.WATER ON A green LED indicating when the water is on.

Table 4.6 - Model T-182/T-184, Front Panel Control Descriptions



4.8.2 Model T-182/T-184 Power Supply Connections

The connection points mounted on the rear panel of the Model T-182/T-184 Power Supply aredescribed below and identified in Figure 4.14 and described in Table 4.7.

(INPUT AC)

LE000269A

Figure 4.14 - Model T-182/T-184 Power Supply, Rear Panel Connections.

CONNECTION DESCRIPTIONSK 1 110/120V Output to the Model 8706 unit.SK 2 110/120V Output to the Model 8732 unit.F1 2 amp fuse protecting SK1 outputF2 1 amp fuse protecting SK2 outputSK 3 Output to water flow meter (either 110v or 240v depending on unit)SK 4 Output to water booster pump (either 110v or 240v depending on unit)SK 5 VACUUM INTERLOCK 24V DC vacuum interlockSK 6 WATER SENSOR Water flow interlockPOWER A rocker switch sets mains power, ON/OFF.MAINS A fixed three-pin mains input connection point for 220/240 V at 50 Hz.

or A fixed three-pin mains input connection point for 110 V at 60 Hz.

Table 4.7- Model T-182/T-184, Rear Panel Connection Descriptions

4.9 Flow Switch Meter AssemblyThe flow switch meter is supplied as a loose item which has to be plumbed and wired into thesystem by the customer to suit the available system. The unit is normally fitted in the return waterline after the Ion source. Two cables are supplied pre-wired into the flow meter. The mains cable isto be fitted to SK3 Water Monitor on the back of the Model T-182/T-184 Unit and the Interlock cableis to be fitted to SK5 Water Sensor point on the back of the Model T-182 or T-184 Unit.

Figure 4.15 - Flow Switch Assembly (240v)

HA030012 Installation


5 InstallationThermo VG Scientific has carefully packed the Monochromator X-ray Source, the Model 8706Power Supply, the Model 8732 Control Unit and the Model T-182/T-184 Power Supply so that theywill reach their destination in perfect operating order. Do NOT discard any packing materials. Checkall units have been inspected for any transit damage and that each unit has been used to thecustomers satisfaction. The packing should be retained for re-use if the instrument has to bereturned in the future.

If any damage is found, notify the carrier and Thermo VG Scientific (or local agent) immediately. If itis necessary to return the shipment, use the packaging as supplied and follow the instructions inthis manual for return of goods paragraph 3.2.

5.1 Unpacking ChecklistThe Equipment package will normally be despatched from the factory in two boxes with liftinghandles. Inside the boxes the following will be found, refer to and check each item off against thesupplied packing list.

◆◆◆◆ Monochromator Chamber Complete - packed in its own box with internal packagingDo not remove the instrument from its internal packing (polystyrene inserts andpolythene bag) until the unit is ready to be installed.

Unpack all other units with care, inspecting each item for damage.◆◆◆◆ Model 8706 Control Unit - packed within pink polystyrene inserts.◆◆◆◆ Model 8732 Control Unit - packed within pink polystyrene inserts.◆◆◆◆ Model T-182 or T-184 Control Unit - packed within pink polystyrene inserts.◆ XR501 - Mounting Kit - packed in a polythene bag.◆ Optional Spares - packed individually.

◆ Documentation - Inserted in a folder, containing the operating manual, wiring drawings(if requested) test certificates and a standard forms pack.

5.1.1 Preparation(a) The electronic units should be rack mounted, ensure that the rack is suitably positioned.(b) Ensure that a suitable mains electricity supply (110 Vac or 240 Vac) is available. The

Electronic Units are NOT auto-ranging and are available in either 110Vac or 240 Vacversions, ensure the correct units have been purchased to suit your local supply.

(c) Ensure that a suitable cooling water supply (minimum pressure 3.6 Bar with booster pump,5.7 Bar without booster pump) is available. A minimum flow rate of 3.0 litres/minute of cleanfiltered water is required, distilled water is preferred (de-ionized water should not be used).

(d) Ensure that the vacuum chamber to which the Monochromator Chamber is to be fitted has asuitable port available, both for position and size (FC64) and that installation of the Chamberand X-ray Source will not impede any other structure.

5.1.2 Installation GeneralFit instruments to the vacuum chamber using the following technique :(a) Ensure that the Gasket (supplied in the Mounting Kit) is seated centrally on the vacuum

chamber flange and that during subsequent operations the gasket and instrument flangeremain concentric with the vacuum chamber flange. Do not touch the surfaces of newgaskets with bare hands as the natural oils on the skin will cause contamination.

(b) Lubricate the threads of the screws with anti-seize heat resitant lubricant (supplied in theMounting Kit) before use.

(c) Secure the instrument by partially tightening each diametrically opposite pair of Bolts(supplied in the Mounting Kit) in turn. Tighten all the bolts in steps of a quarter turn, in orderto maintain an approximately even pressure across the whole surface of the gasket until allbolts are tight.

Installation HA030012


5.2 Hardware InstallationCAUTION

Ensure standard procedures for handling vacuumcomponents are adhered with.

See Maintenance - General section 7.1

(a) Fit the Monochromator Chamber:(i) Remove the Monochromator Chamber from its packaging; inspect for transit damage.

(ii) Using a new copper gasket position the Monochromator Chamber on the vacuumchamber flange.

(iii) Secure the Monochromator Chamber to the vacuum chamber using the generalassembly techniques.

(iv) The Monochromator Chamber must be fully supported, (to avoid stress distortion ofthe vacuum chamber).

(b) Fit the Crystal Manipulator:

The Crystal used in the Crystal Manipulator has a temperature limitation and must NOTexceed 120oC, If Bakeout to a temperature > 100°C is envisaged, fit a blank flange using anew copper gasket to the FC150 (Crystal Manipulator) port, of the Monochromator Chamber.

If Bakeout to a temperature < 120°C is envisaged, fit the Crystal Manipulator to the FC150port.

Note: Do not fit the Crystal Manipulator prior to the system being baked, fit after bakeout.

(i) Unpack the Crystal Manipulator and Crystals and inspect for transit damage.

(ii) Using a new copper gasket position the Crystal Manipulator on the FC150 flange.

(iii) Secure the Crystal Manipulator to the Monochromator Chamber using the generaltechnique.

(c) Fit Lead Glass Covers over all other view ports.


X-rays are emmitted by this source.Ensure that all viewports are leaded glass or are screened

to prevent the radiation of X-rays.

(d) Secure the Electronic Units in a standard 19” electronics rack next to the vacuum system.Set all electronic unit power switches to OFF.

Note: The Model 8732 Power Supply has been supplied with a 6mm thick foam pad between theperspex lid and the arc suppressor, this is for shipment only, and must be removed prior touse.

(e) Set up the Chiller/Re-circulator if supplied. Fluid connections should be made with correctlysized plastic, rubber or copper tubing, sensibly connected with clips where necessary. Airmust be expelled from the water circuit for satisfactory operation. Entrapped or emulsified aircan be removed from the reservoir by running the unit for brief period and re-filling thereservoir as necessary.

WARNINGDo NOT depress button “P” as this will change the program.



5.3 PipeworkA suggested pipework layout is shown below:

Figure 5.1 - Pipework Layout

Figure 5.2 - Water Connections to the Electron Gun

5.3.1 Differential PumpingThe main chamber of the Monochromator is designed to be differentially pumped to balance thepressure each side of the aluminium window. This can be done by either fitting a small Ion pumpdirectly onto the side port of the Monochromator chamber, a suggested size would be a minimum of70 litres/second, or by fitting pipework directly from a spare port on the analysis chamber.



5.4 Evacuation / Bakeout


During bakeout the vacuum system is at a high enoughtemperature to cause serious injury.

Ensure that only suitably trained personnel are allowed in thevicinity of the equipment.

CAUTIONDuring bakeout the temperature of the vacuum system could damage sensitive components.

Ensure that all heat sensitive components, eg. Crystals, cameras and all cable assembliesare removed from the system before the bakeout procedure is started.

-----------------------------------------------------------------------------Malfunctions during bakeout may cause damage to the system or components.

Detection systems to protect against overheating, over- pressure and leaks, should be fitted.

CAUTIONCool spots during bakeout will lessen the effectiveness of the bakeout procedure.

Ensure that the insulation of the system is complete (without gaps) and that all parts of thesystem are at an even temperature.

Ensure that the Crystal Manipulator has not been fitted prior to the initial high temperature bakeout.

(a) Commence evacuating the system.

(b) If the integrity of the vacuum is suspect, carry out a leak test.

(c) When the chamber pressure reaches 10-5 mbar, commence baking the system.

(d) Whilst evacuation continues, bake the system at not more than 200°C (recommendedtemperature 180°C), for not less than 8 hours.

(e) After bakeout is complete allow the system to cool (minimum of 5 hours prior to removal ofoven covers), Cooling may be assisted by the use of fans, before continuing the installationprocess.

5.4.1 BakeoutTo ensure satisfactory operation the Monochromated X-ray Gun should be subjected to a bakeoutprocedure each time the system is let up to atmosphere. Ensure that the Crystal Manipulator hasbeen removed if the bakeout temperature is to exceed 1200C.

Baking removes contamination and moisture from within the sysyem. The rate of evacuation of thevacuum system by high vacuum pumps is limited by gases and moisture slowly desorbing from thevacuum chamber walls and from components within the chamber. In a new system these gaseswill consist of normal atmospheric gases and also cleaning residues and other contaminants. Thelimitations imposed by these desorbing gases can make it impossible to achieve ultra high vacuumpressures within an acceptable time scale.

Baking the system accelerates the desorption process and pump down times are greatly reduced.After the baking process has been completed, the vacuum greatly improves as the system cools.



5.4.2 System / Component Bakeout(a) Initial Bakeout

For a new system or component, bakeout at a temperature of between 200°C and 230°C isrequired in order to achieve a vacuum pressure of 10-8 mbar or better. Systems andcomponents supplied by Thermo VG Scientific are checked at these limits before leaving thefactory, but will require this initial bakeout when first installed on a new system

(b) Subsequent BakeoutOnce systems or components have been baked (as above), unless they have been severelycontaminated, the bakeout temperature can be set at 1500C to 1800C (1800C isrecommended).Most UHV components can withstand temperatures over 2000C (up to 2300C). Heatsensitive components should be removed from the system before baking, these includeCameras, Crystals, all Cable Assemblies. (fit blank flanges where necessary). After thebakeout process has been completed the heat sensitive components may be refitted to thesystem. If the integrity of the vacuum system will be lost during refitting, maintain a flow ofclean, dry gas (argon is preferred) through the system to minimise contamination of thesystem. The system may be subjected to a second baking, at a lower temperature (to suit theheat sensitive components) whilst restoring the vacuum pressure.

After the initial bakeout process has been carried out, or a new single component is added toan existing system, later bakeout pumping processes can be accomplished using an ionpump, provided that the bakeout process can be temporarily suspended if the vacuumpressure becomes too high.

(c) PumpingDuring the initial bakeout of a new system, desorption produces a large quantity of gas, and aturbo pump or diffusion pump is recommended. This pump, which allows the gas to escapefrom the system will generally allow the system to bake continuously without tripping thepumping system. If necessary a turbo or diffusion pump, which would not otherwise berequired, can be temporarily connected to the system.

(d) Heating Methods(i) Collapsible Oven Panel Surrounds

The most effective method of performing the bakeout process is to mount the vacuumchamber on a heat insulated bench to which heating elements are affixed andsurround the complete vacuum system with insulated panels. For a typical twochamber system, between six and eight, 1kW heater elements are required. Smallgaps between the panels can be filled with aluminium foil in order to minimize the heatloss.Effective control of the system can be provided by a thermocouple to control themaximum temperature, interlocked with an Ion gauge controller to ensure vacuumpressure cannot rise too high. In the event of the temperature or vacuum pressurerising above the set limits, heating will be temporarily suspended.

(ii) Infrared heatersInfrared heaters (available from Vacuum Generators) which are mounted on a 70 mmconflat flange can be used for localised internal bakeout. They are most successful atdirect line desorption from the chamber walls, but are less successful for systems withcomponents which do not protrude into the chamber.

(iii) Heating tapeA popular and inexpensive way of baking is by use of heating tapes wrapped aroundthe chamber and components. Aluminium foil covering the system helps to provide aneven heat distribution. Great care must be taken to ensure the absence of hot and coldspots. This technique can be used together with internal infrared heating.



5.4.3 Fit Crystal ManipulatorIf the Crystal Manipulator is not yet fitted (due to high temperature Bakeout) proceed as follows:

(i) Bring the system back to atmospheric pressure using dry nitrogen or argon. (To avoidcontamination of the chamber, maintain the gas flow during (ii) and (iii) below.)

(ii) Remove the blank flange from the Monochromator Chamber FC150 port, discard thegasket.

(iii) Fit the Crystal Manipulator, see Paragraph 5.2.(b).

(iv) Evacuate and Bakeout to a temperature not exceeding 120°C.

5.5 System Wiring


Potentially lethal voltages are used in this equipment.Before making / breaking connections to the equipment, ensure power is

switched off at the Power Supply.

CAUTIONIt is important that the connectors to the x-ray source are kept free from contamination

which could cause high voltage arcing and consequential damage.Ensure that all surfaces are throughly clean and dry.

---------------------------------------------------------

If earth braid connections are insecure and a flashover occurs the power supply may bedamaged.

Ensure that earth connections are fully tightened prior to switching on the Power Supplyeach time it is used.

---------------------------------------------------------The efficiency of cooling will be reduced if the water connections are incorrect.

Ensure that the input and output connections are correctly made.



5.5.1 Cable ConnectionsThe connections between the X-ray Source and the Electronics units are to be made are indicatedin Figure 5.3 and described as follows.

Figure 5.3 - System Connections (T-182 Supply shown)

(a) Connections on the back of the Model 8706 (Glassman) unit.(i) Cable from the HV output to –10KV IN on the Model 8732 unit.(ii) Interlock cable from J3 to –10KV I/L on the Model 8732 unit.(iii) Mains cable for the 110 V input supply from SK2 on the Model T-182/T-184.

(b) Connections on the back of the Model 8732 unit.(i) Cable from the –10KV IN input to the RV connection on the Model 8706 unit.(ii) Interlock cable from –10KV I/L to J3 on the Model 8706 unit.(iii) Mains cable for the 110 V input supply from SK1 on the Model T-182/T-184.(iv) Interlock cable from SYSTEM I/LIN to VACUUM INTERLOCK on the T-182/T-184 unit.(v) Integral cable from GUN O/P to the multi pin connector on the end of the Electron Gun.

Note: When not connected, the flying lead cable from the Model 8732 unit to the Electron gun mustbe kept covered, to prevent contamination, which could cause high voltage arcing andconsequential damage.

(c) Connections on the back of the Model T-182/T-184 unit.(i) Mains output cable from SK1 (110 V) supply to the Model 8732 unit.(ii) Mains output cable from SK2 (110 V) supply to the Model 8706 unit.(iii) Flying lead from the the Water Flow Meter to SK3 connector.(iv) Lead from the the Water Booster Pump to SK4 connector.(vi) Interlock cable from SK5 to SYSTEM I/LIN on the 8732 unit.(v) Flying interlock lead from the the Water Flow Meter to SK6 connector.(vi) Mains input cable.

Operation HA030012


6 OperationThe X-ray Gun system is designed to be durable and has a long lifetime. The Source does containitems, primarily the Filament and Anode that have finite lifetimes, in order to sustain optimumperformance they will need replacing periodically. The lifespan of the Filament is dependant on anumber of factors, including operation in a good vacuum <1x10-8 mbar, preventing the Sourcebeing subjected to thermal shock, rate of ramping the current up or down, preventing the systembeing contaminated and maintaining a vacuum within the system when not in use.

6.1 Procedure Notes(a) This instrument must not be used until it has been fully degassed (see paragraph 6.2).

(b) Start Up procedure, (see paragraph 6.4).

(c) If the system has been in use, allow 30 minutes for the Filament to cool before admitting gas.

(d) Admit only clean, dry, dust free gas (e.g. dry nitrigen).

(e) Ensure that the system vacuum pressure is better than 10-8 mbar, before the system is set towork.

(f) During routine operations monitor the system pressure to ensure that pressure does not riseabove 10-8 mbar.

(g) Minor changes in pressure during routine operations are normal. When small increases inpressure are noted, allow the vacuum to recover before continuing operations.

(h) Close Down procedure, (see paragraph 6.5).

6.1.1 Cooling Water(a) Water Pressure

A minimum pressure of 4 Bar (60 psi) is required, with or without booster pump, to givea flow of 3.5 litres per minute at the x-ray anode. The maximum recommended waterpressure for x-ray sources is 5 bar (75 psi).

If a booster pump is supplied, there should be no difficulty achieving the requiredpressure. If the booster pump and water supply are working correctly, any decrease inthe water flow may be caused by blockage of the cooling lines. This can be cleared byreversing the water connections on the back of the anode, thus running water throughthe anode in the opposite direction. Repeating this operation a few times will oftenclear blockages.

(b) Water PurityDistilled water containing 10% alcohol (Ethyl alcohol is recommended) should be usedas the coolant. The alcohol prevents the build up of algae in the cooling system thatmay eventually block the filters.De-ionised water should NOT be used, as minute particles from the de-ionising unitmay be present.Ordinary tap water should NOT be used, as this often has a high mineral contentleading to the build up of scale in the cooling system that may affect the operation ofthe flow switch.De-mineralised water is NOT recommended, as when the water is de-mineralisedthere is a high level of aggressive ions left behind. These can corrode the stainlesssteel tubing within the anode.Particulate matter, e.g. iron or copper, in the water can cause excessive leakagecurrent because of charge being transported on the particles. In extreme cases this willoverload the power supply. This can be prevented by using a 60 micron filter in theinlet (before the booster pump, if supplied).

HA030012 Operation


(c) Water TemperatureIdeally the X-ray should be operated between 150C and 200C. The water inlettemperature should not be cooler than the room temperature otherwise condensationwill form, however the inlet temperature should not exceed 250C.

(d) Electrical Properties of WaterResistance >1.5MW, to give leakage at 15 Kv of less than 10mA over the length of thex-ray conduit.An internal trip will activate if the leakage current down the water lines exceeds 10-15mA. If distilled water (with 10% Ethanol) is used this should not be a problem.The use of "softened" water can cause problems where the conductivity is very high.

(e) OperationTurn water supplies ON before setting Model T-182 or T-184 Control Unit to ON.

If cooling water supplies are inadequate an interlock will inhibit the operation of the powersupplies.

After switching OFF the X-ray Gun Model 8706 Power Supply, wait a few minutes beforeturning water supplies OFF.

6.1.2 Radiation TestingIt is good working practice to check the Vacuum System / X-ray Gun for radiation leaks. This shouldbe done as soon as possible after the installation procedure has been completed.

The maximum allowable radiation dosage must not exceed that set by local regulations.

6.2 Degassing the MonochromatorNote - This procedure (which can take several hours) should be done at the following times:

(i) After the installation procedure (Chapter 5) has been completed.

(ii) After replacement of the filament/cathode.


COMPETENCE OF PERSONS CAPABLE OF CARRYING OUT THEDEGASSING PROCEDURE WITH I-8732 X-RAY CONTROLLER

Potentially lethal voltages are used in this equipment.

IF YOU ARE IN ANY DOUBT REGARDING THE FOLLOWINGPROCEDURES NO ATTEMPT SHOULD BE MADE TO CARRYTHEM OUT. INSTEAD CONTACT YOUR LOCAL THERMO VG

SCIENTIFIC REPRESENTATIVE FOR ASSISTANCE.

In order to carry out the degassing procedure with the I-8732 X-ray controller a level of electricalcompetence is required.

This level of competence should be either through qualifications, experience or training.

Operation HA030012


The requirement for this competence is due the fact that the unit will have to be isolated from theincoming supply and covers will have to be removed which will expose the engineer to lethalvoltages. (10kV at up to 30 mAmps)

As already mentioned the unit will have to be isolated and disconnected from the incoming mainssupply in order for the top cover to be removed. It will then have to be placed in a suitable place tocarry out the adjustments.

The normal precautions for working with high voltages should then be put in place. i.e. A rubbermat should be provided for the engineer to stand on, The area should be barricaded off andsuitable warning signs put in place. Other people should be in the vicinity to provide assistance inthe event of an accident.

The potentiometers that have to be adjusted are at a high potential. In order for these to beadjusted safely their shaft have been extended through the perspex top cover using insulatingmaterial. However care should still be taken when making the adjustments due to the Highvoltages involved

(a) On the Model 8732 X-ray controller in the X-ray rack, set the METER FUNCTION switch toI2kV (20mA) and turn the SPOT SIZE control to OFF.


Potentially lethal voltages are used in this equipment.During the following procedure terminations at lethal voltages may be

exposed.

(b) Remove the four rack panel screws and slide out the controller unit ensuring the cables arenot strained. Suitably support the unit.

(c) Remove the top cover and replace the left hand screw which acts as a cover interlock.

(d) Ensure the area is roped off and adequate warning signs are displayed.

(e) Refer to Figure 6.1 and locate the potentiometers inside the controller.

(f) If the spot size and beam power have not already been set during a previous alignmentprocedure or if a new filament is being degassed for the first time, turn all the BEAMPOWER, FOCUS and RP1 potentiometers fully counter-clockwise.

If the spot size and beam power have already been set (i.e. a new installation), turn only RP1fully counter-clockwise.

Note: Step (f) is carried out to ensure that the filament is not outgassed onto a clean anduseful part of the Aluminium anode and to ensure that unduly high power deposits arenot generated on the anode face.

(g) On the Model 8706 power supply, turn the voltage down to 0.

(h) Press and hold the WATER FLOW switch on the Model T-182 to start water flow through theX-ray source. Release the switch when the WATER FLOW indicator remains in a steady onstate.

(i) Switch on the Model 8732 controller and the Model 8706 supply following the normalprocedure for starting up the mono source.

(j) Press PRE-HEAT on the Model 8732 controller and wait for the READY light to come on. Ifthe light does not come on within about 30 seconds check all the interlocks.

(k) Slowly increase the bombardment current by turning RP1 clockwise. Keep the pressurebelow 1 x 10-8mbar in the analysis chamber and monitor the current on the analogue metermounted on the front of the Model 8732 controller.

• For a 50Hz system increase the bombardment current until 7.5Ma is reached orthe value preset by Thermo VG Scientific and noted on the unit is reached.

This process should take at least 30 minutes to perform.

HA030012 Operation


Figure 6.1: Layout of Model 8732 X-ray Controller

(l) Increase the high voltage on the Model 8706 supply to 10Kv checking for flashover. Note thata small current of the order of 2mA will be registered due to the bias currents of the gunfocus supply.

(m) If the operating current has already been set for the different spot sizes switch to the largerspot sizes in turn, waiting for the pressure to settle and then leave the gun at the larger spotsize for at least 30 minutes to fully degas the gun. This is the normal procedure in mostinstances.

(n) If the operating current has not been set for each of the different spot sizes, refer to the tablebelow and set the operating current, as displayed on the Model 8706 for the four differentspot sizes following the procedure described below;

Spot Size Power(watts)

Emission Current(mA)

100 15 1.5150 45 4.5

150 x 800 100 10250 x 1000 200 20

Table 6.1 Model 8706 Settings.

(o) Turn the SPOT SIZE control on the Model 8732 controller to the 100 micron spot setting. Thecurrent and pressure will now rise.

(p) Locate the BEAM POWER potentiometer for the 100 micron spot and turn clockwise to givea current reading of 1.5mA plus the leakage current. In other words, if the leakage current is2.25mA adjust the 100 micron pot until a reading of 3.75mA is shown. Allow the pressure tosettle and then move on to the next spot size, setting the beam current in a similar fashion tothe first using the figures from the table. Should the desired power not be achievable with thepotentiometer fully clockwise, turn all focus and beam power potentiometers fully anti-clockwise, increase RP1 until the bombardment current is 0.25mA higher and repeat thepower setting procedure.

(q) Leave the pressure to settle between spot sizes and leave the system at the largest spot sizefor at least 30 minutes to fully outgas the X-ray source.

(r) The degas procedure is now complete and the alignment of the monochromator should nowbe set or checked.

Operation HA030012


6.3 Aligning the Monochromator

6.3.1 Check the Calibration of the Analyser(a) Load silver and phosphor test samples and position the silver sample at the analysis position.

(b) Using a broad Al Kα X-ray source, record a spectrum of Ag3d5/2 peak at low and highresolution (i.e. low and high pass energy respectively). Ensure that the peak is central is368.27eV. (BE) (1118.35 eV. KE) at both high and low resolution.

6.3.2 Coarse Adjustment of the MonochromatorWhen starting with a new monochromator that has never been run before, the task is to find someX-rays on the phosphor, and this can present some initial difficulties. The largest piece of phosphorpossible should be placed at the analysis position.

If the monochromator is roughly in correct adjustment and the X-ray spot(s) can be seen on thephosphor, then leave this section and go to Section 6.3.3 for fine adjustment of the monochromator.

Otherwise, proceed as follows:

(a) Switch on the 250µm spot as this is a sharp, intense spot.

(b) Slacken the adjuster nuts on the lower leg assembly to allow the lower leg to move to its fullextent of travel.

(c) Whilst watching the phosphor, push the lower leg across its full extent of travel. If the spotsbecome visible the leg should be locked in place and fine adjustment to the spots should bemade according to section 6.3.3. if the spots do not become visible continue with thefollowing procedure.

(d) Beginning with one crystal, set all three micrometers to their nominal mid-heights (about2.5mm from the bottom).

(e) Open the X-ray window by turning the rotary drive to exactly half-way between its end stops.

(f) Switch the source to the 1mm spot size for maximum intensity. Emission from theX-ray source should be observable on the phosphor screen. There may also be a faint greenglow over the whole of the screen, produced by electrons scattered from the source.

(g) Adjust each of the crystal tilt micrometers in turn to maximise the intensity of the light seen onthe phosphor screen. It may now be possible to eventually make out a faint optical image ofthe X-ray source region and possibly a brighter green fluorescence spot produced by X-raystravelling around the monochromator.

(h) If the fluorescence spot is not visible adjust the monochromator leg as follows:

(i) Tilt the monochromator chamber leg inwards, so that the bottom end is approximately10mm further in than it would be if the leg were straight.

(ii) Observe the sample through the viewport and check for fluorescence while rocking thecrystals back and forth in the dispersive direction only, using the dispersivemicrometers.

(iii) If fluorescence cannot be found, move the leg outwards by turning the adjusting nutsapproximately one turn in a clockwise direction, and again rock the crystal to and frowhile watching the sample for fluorescence. Continue this process until the greenfluorescence of the X-ray is found.

(i) When the fluorescence spot position is established, adjust the leg position and the dispersivetilt to produce the brightest spot at the analysis position.

(j) Fine tune the position of the beam to the analyser position using a CCD microscope or otherviewing system.

(k) Repeat the whole procedure for the other crystal.

HA030012 Operation


6.3.3 Fine Adjustment of the MonochromatorTo make the fine adjustments, again begin using one crystal only.

(a) Move the spot from the crystal not being adjusted, slightly out of the field of view, by turningthe non-dispersive tilt micrometer a fraction of a turn, but not so far that it has movedcompletely off the phosphor and cannot be found again easily.

(b) Switch the source to the 150µm spot. If the source has been previously set up this gives thebest compromise between intensity and the small spot size necessary to adjust the focus. Ifthe Source has never been run before it is safer to use the 100µm spot, as the gun focus forthis spot size can be adjusted without risk of damaging the anode.

(c) Raise and lower the sample while watching the spot on the phosphor, to establish whetherthe focal point for the monochromator is above or below the sample position. If the focus isbelow the correct sample height it will be necessary to raise the crystal, if above, the crystalwill have to be lowered. The crystal will have to be moved by half the change in sampleheight.

(d) Record the current crystal micrometer settings so that the spot may be repositioned ifrequired.

(e) Calculate the new crystal height and begin to raise/lower the crystal towards its new height,by adjusting each of the three micrometers (a small movement) in turn, a small amountkeeping the spot on the phosphor all the time.

Note: Changing the crystal height alters the angle between the source and the surface of thecrystal. If the height has been changed significantly, the spot may have lost intensity and itmight be necessary to swing the leg inwards a little if the crystal was lowered, or outwards if itwas raised, to regain the correct Bragg angle. It will also be necessary to rock the crystal alittle, to position the spot at the centre of the analysis position again. However, as it is verydifficult to estimate intensities from the phosphor, which is highly non-linear, it may be betterto make this adjustment later, using the spectral intensity from the silver sample.

(f) Check that the new crystal height gives a good focus at exactly (±0.5mm) the correct sampleheight.

(g) If the 100µm spot is being used on a source that has not been run before, adjust the gunfocus potentiometer in the Model 8732 power supply to minimise the spot size. This providesa more sensitive means of determining the correct crystal height. As this procedure involvesinternal adjustment inside the unit, the procedure MUST be carried out by a suitably qualifiedelectrical engineer, refer to section 6.2 for specific instructions on obtaining the information.

(h) Measure the spot size by inference on the TV-microscope image, and verify that it is lessthan 100µm in diameter. Set the focus potentiometers for the other spots by adjusting thefocus potentiometers in the Model 8732 power supply to produce diameters of 150µm,400µm and 1000µm respectively. As this procedure involves internal adjustment inside theunit, the procedure MUST be carried out by a suitably qualified electrical engineer, refer tosection 6.2 for specific instructions on obtaining the information.

(i) Move the set up crystal slightly out of the field of view by turning the non-dispersive crystalpotentiometer. Do not move the spot off the phosphor screen.

(j) Repeat the procedure from step (b) to step (f) for the un-aligned crystal.(k) Move the sample up and down a little while observing the fluorescence spots and check that

both crystals are focused at the same height.(l) Check Ag 3d5/2 peak is at 1118.35eV. If the peak energy is lower than 1118.35eV, it will be

necessary to move the monochromator leg outwards to decrease the Bragg angle andincrease the X-ray energy. If the energy was too high, move the leg inwards. Move themonochromator leg inwards or outwards, as required, by 1/6 turn of the leg adjuster nut. Asnecessary adjust the crystal dispersive tilt to re-position the beam at the analysis position.

(m) Repeat this task very carefully, until no further improvement is achieved. Finally adjust thenon-dispersive tilt to optimise the count rate. Repeat the above procedure for the other crystalbut do not adjust the position of the leg. By adjustment of the non-dispersive micrometersand very careful fine adjustment of the dispersive micrometers, maximise the count rate toalign the spots in the analysis position. Confirm the alignment by looking at the spots on thephosphor screen.

Operation HA030012


6.4 Monochromator Start UpBefore starting the X-ray source, ensure that the filament has been thoroughly outgassed.

The small spot monochromator produces a sharply-focused X-ray beam for high-resolution work. Itis controlled by two units, the Model 8706 Glassman HV power supply and the 8732 X-raycontroller. The Model 8706 supply provides the HV (or EHT) for the monochromator supply. TheModel 8732 unit controls the filament current, X-ray source emission and the shape of the beamleaving the electron gun on the X-ray source.

To start the water flow and set the filament current, proceed as follows.

(a) On the Model T-182/T-184 Unit press the water on switch and hold until the LED lights areon.

(b) On the Model 8732 X-ray controller, press the LINE button. This switches the unit on. Thegreen interlock LED is now lit.

(c) On the Model 8732 X-ray controller, set the METER FUNCTION switch to I FIL.

(d) On the Model 8732 X-ray controller, set the SPOT SIZE switch to OFF.

(e) On the Model 8732 X-ray controller, press the PRE-HEAT button. The filament currentshould now rise to just over 1.0A and then settle back to just below 1.0A. After a shortinterval the yellow READY led is lit, indicating that the filament current is established and youcan proceed to the next stage.

To start the X-ray source, proceed as follows.

(a) Check that the pressure in the analysis chamber is below 1x10-8mbar.

(b) On the Model 8706 HV unit, check that the KILOVOLTS control is set to zero(in the fully anti-clockwise position).

(c) Operate the POWER rocker switch to switch on the Model 8706 HV unit.

(d) Press the green HIGH VOLTAGE ON button.

(e) Slowly increase the KILOVOLTS control until 10kV is reached.

If any flashovers occur whilst applying high voltage, a vacuum burst may also occur. If aflashover occurs reduce the voltage, wait a few moments while the system pressure recoversthen continue to increase the voltage slowly.

(f) Check that the leakage current displayed on the current meter is approximately 2.25mA at10kV. If there is a major discrepancy there is a problem and you must seek service advice.

(g) Select the required emission spot using the SPOT SIZE selector.

6.5 Shut DownWhen closing down a system, turn off the Electronic Units using the following procedure:

(a) Turn the SPOT SIZE knob on the Model 8732 to OFF.

(b) Turn the KV control to zero on the Model 8732.

(c) Turn off the Model 8706 Glassman unit mains supply.

(b) Turn off the LINE control on the Model 8732.

(c) Turn off the Model T-182/T-184 Control Unit.

HA030012 Maintenance


7 Maintenance7.1 Maintenance – General Notes


Potentially lethal voltages are used in this equipment. Before making / breaking connections to the equipment, ensure power

is switched off on the the Electronics units.

CAUTIONOnce the Instrument has been opened or removed from the vacuum system it must be

protected against airbourne dust and sealed from the atmosphere.

It is advisable that work on items removed from the vacuum system is carried out in a cleanroom environment (minimum class 10,000).

If a suitable clean room environment is not available, the unit may be returned to ThermoVG Scientific for repair (see paragraph 3.2) .

The procedures listed in this chapter should only be attempted by persons who have had trainingand who have achieved a satisfactory knowledge of the necessary skills and techniques inmaintaining instruments from a high vacuum environment.

(a) If repairs entail the dismantling of any part of the system, care must be taken to ensure that itis not contaminated by:

(i) Grease and moisture from hands - Always wear gloves.

(ii) Avoid handling any internal surfaces.

(b) If surfaces are inadvertently contaminated, clean by wiping with a lint free tissue moistenedwith Acetone or Isopropanol.

(c) If repairs involve the dismantling of any parts mounted on copper gaskets, refit using newcopper gaskets, (do not touch new gaskets with bare hands to avoid contamination). Secureparts with gaskets using the following technique:

(i) Ensure the gasket is seated centrally on the main assembly flange and that duringsubsequent operations the gasket and replacement part flange remain concentric withthe main assembly flange.

(ii) Lubricate the screws with anti-seize heat resistant lubricant (supplied in the MountingKit) before use.

(iii) Secure the part to the main assembly by partially tightening each diametrically oppositepair of screws in turn. Tighten all the screws in steps, in order to maintain anapproximately even pressure across the whole surface of the gasket.

(d) Screws and screw threads inside the vacuum may become tight after bakeout, and mayseize if forced. If any difficulty is experienced when turning screws, lubricate the screwthreads with Isopropanol or methyl alcohol.

Note: Take care not to scratch or damage any knife edge sealing face on flanges whenremoving instruments or used gaskets.

Maintenance HA030012


7.2 Dual Crystal Manipulator

7.2.1 Micrometer AdjustersReplacing and lubricating the Micrometer Adjusters, refer to Figure 7.1

Figure 7.1 Micrometer Adjusters

(a) Refer to Figure 7.1 and remove the two M3 grub screws at the base of each micrometer.

(b) Release the micrometer by unscrewing the knurled ring at the bottom of the micrometer.

(c) Remove the micrometer.

(d) Slide out the copper sleeve from inside the micrometer housing on the manipulator.

(e) Use a wire brush to polish the inner bore of the copper insert to remove any burnishes.Finally polish in some of the dry graphite provided.

(f) Fit the copper sleeve and micrometer into the manipulator and screw in the two M3 grubscrews.

(g) Secure the micrometer by tightening the knurled locking ring.

7.2.2 Removing the manipulator(a) Vent the system.

(b) Scribe two marks across the manipulator/chamber flanges. These marks will be used toensure correct alignment during assembly.

(c) Remove the 26 nuts and bolts securing the manipulator to the monochromator chamber.

(d) Lift the manipulator assembly away from the chamber and place in a protective enclosure.Transport the manipulator to a clean area.

(e) Fit a protective cover over the chamber.

7.2.3 Fitting the manipulator(a) Remove the protective covers from the manipulator and the chamber.

(b) Position the manipulator so the scribe marks are exactly aligned.

(c) Fit the 26 nuts and bolts finger tight. In turn tighten opposite pairs of nuts and bolts to ensureflanges are not distorted.

(d) Pump, bake and degas the system as described in Chapter 6.



7.3 Aluminium Window ReplacementIf the aluminium window between the crystals and the sample becomes torn then it will need to bereplaced. If it is suspected that fragments of the foil have been sucked into other parts of thesystem then a more thorough inspection would be necessary.

Figure 7.2 - The Aluminium Monochromator Window and Rotary Drive

(a) Vent the system to dry nitrogen.

(b) Remove the crystal assembly from the rear of the instrument taking a note of the orientationof the flange.

(c) Wearing gloves, remove the window assembly from the rotary drive by loosening the twogrub screws on the shaft. Place the assembly on a clean work bench.

(d) Remove the 6 screws and separate the two halves of the assembly and remove all the oldaluminium foil.

(e) Take a new sheet of foil. This is supplied in a square sheet (160mm x 160mm, VGS part no.ALS075), sandwiched between two sheets of card, which is sufficient to make two windows.Cut this while still sandwiched between the card to an approximate size of 80mm x 160mm.

(f) Separate the card and lay the Al foil on one half of the window assembly. The foil is verydelicate and can tear easily, however, with care, it can be positioned using a pair tweezers.Be careful not to drag the foil over any sharp ends on the guide wires.

(g) With the foil in position place the second half of the window assembly on top, being careful toalign the two halves.

(h) Using a sharp tool make a guide hole in the foil in each of the screw holes.

(i) Insert the screws and tighten.

(j) Replace the assembly on the rotary drive being careful to check orientation, i.e. the correctpositions for "open" and "closed" leave in the "open" position.

(k) Replace the crystal assembly checking orientation.



7.4 Lower Leg Assembly

7.4.1 Replacing the Mono X-ray Gun Anode

Figure 7.3 - Separate Anode Assembly

(a) If the monochromator has been running then turn the power off to the monochromator sourceand allow the gun and anode to cool for at least 1 hour.

(b) Vent the system.

(c) Unscrew the monochromator gun cable from the monochromator gun and lay out of the way.

(d) Turn off the water supply to the monochromator source. Refer to Figure 7.3 and detach thewater lines going to the anode assembly. Blow out any excess water remaining in the monowater lines using compressed gas.

(f) Remove the bolts retaining the anode assembly to the monochromator chamber andcarefully lift away the anode assembly. Discard the old copper gasket.

(g) Using UHV compatible gloves and a clean allen key, remove the anode retaining ring andremove the old anode.

(h) Clean the anode holder conflat flange with lint free tissue and alcohol.

(i) Fit the new anode face. Note that this does not need aligning as per previous versions of theanode assembly.

(j) Refit the anode retaining ring and tighten down evenly across each retaining screw.

(k) Refit the anode assembly using a new gasket.

(l) Do not refit the water lines or turn the water supply on.

The system is now ready to be pumped down, baked and degassed in the normal manner.

(m) Once the system is under vacuum, it is strongly recommended that the anode is leakchecked. This can be done via the water lines.

(n) Recheck leak tightness after bake out then refit water lines.



7.4.2 Replacing the Electron Gun Filament

Figure 7.4 - Monochromator Electron Gun

(a) Remove the electron gun from the gun port and discard the 2.75” copper gasket. Refer toFigure 7.4 Suspend the electron gun from its flange (item 1) facing downward, so it isconvenient to work on. Ensure that the gun is stable secure from falling.

(b) “Lubricate” each of the screws (item 5) on the barrel couplings and the cathode couplingscrews (item 6) with a single drop of isopropyl alcohol. Loosen the six socket head cap 0-80screws (item 5) from their respective couplings, slide the couplings up each feedthrough,post in turn, and temporarily re-tighten the screws.

(c) Note the orientation of the cathode and filament assemblies with respect to the Pierceelectrode (item 7).

(d) Remove the three gold plated cathode filament retaining screws (item 4) and the threerectangular washers (item 8).

(e) Carefully remove the filament assembly (items 2 and 10) and set it aside for return to ThermoVG Scientific or for disposal..

(f) Remove the cathode assembly (items 3 and 9) being especially careful not to damage thetungsten spider. Remove all of the cathode assembly spacers (item 9) from the Pierceelectrode.

(g) Inspect the Pierce electrode internally for contamination. If necessary, clean with alcohol orwith alumina bead blasting.

(h) Examine the cathode structure for excessive metallization of the ceramic base anddamage/erosion of the spider support structure or cathode button. Some discoloration of thecathode assembly base can be tolerated without degradation. Where necessary, replace thecathode assembly.

Replacement of the cathode assembly is just the reverse of the above procedure. However, it isessential only to use the spacers shipped with the cathode as they are a factory matched set.

(a) Install the rectangular washers and new gold plated retaining screws.

(b) Connect the filament leads and cathode lead to the feedthrough with the barrel couplings andtighten the screws.

(c) With a digital voltmeter check the resistance of the filament through the feedthrough (typically<0.25ohms).

(d) Similarly, select the highest resistance range of the multimeter and check electrical isolationbetween the cathode and the Pierce electrode (it should be >20 Mega-ohms).

(e) If either of the above two conditions are not met, contact your local Service representative.



7.5 Electronics Units

7.5.1 Model 8706 Glassman Power Supply ReplacementTo replace the Model 8706 Glassman Power Supply Unit:

(a) Isolate the Model 8706 Power Supply Unit from the mains.

(b) Disconnect the J1, J2 and J3 connectors from the rear of the Model 8706 power supply unit.

(c) Remove the four screws securing the front panel to the rack and withdraw the unit.

(d) On the replacement unit check that the following links and capacitor are fitted in the followingpositions on TB1 at the rear of the unit.

1 and 2 Link2 and 3 Capacitor 10,000pF5 and 6 Link8 and 9 Link10 and 11 Link

Table 7.1 Model 8706 Link and Capacitor Settings

(e) Slide the unit into the rack and secure using the four screws.

(f) Refer to Figure 5.2 and connect cables to connectors J1, J2 and J3.

(g) Fit the mains connector to the Power Supply in the rack. The system is now ready to use.

7.5.2 Model 8732 X-ray Controller Replacement(a) To remove the Model 8732 Controller from the rack, isolate the unit from the mains.

(b) Disconnect the J1, J3, J4 and J7 connectors from the rear of the X-ray controller

(c) Remove the four screws securing the front panel to the rack. Withdraw the unit whileensuring sufficient slack is available in the X-ray cable.

(d) Suitably support the unit if repair work is to be carried out.

(e) If the unit is to be removed from the rack the X-ray cable must be disconnected at the gunend of the cable.

(f) To refit the controller, feed the cable through the aperture in the rack and then slide thecontroller into position. Secure the front panel using the four screws.

(g) Refer to Figure 5.2 and connect cables to connectors J1, J3, J4 and J7 to the rear panel ofthe controller.

(h) Fit the mains connector to the Power Supply in the rack. The system is now ready to use.



7.6 E4870PR4 Water Chiller MaintenanceThe E4870PR4 Chiller Re-circulator units requires very little in the way of routine maintenance,however, for optimum performance it is recommended that the following procedure is carried out ona regular basis.

(a) Inspect all connections (water and electrical) for security, leakage and signs of wear.

(b) Clean the outside surfaces of the cabinet with a damp cloth or proprietary equipment cleaner.Finish with a dry, lint free cloth to remove smearing.

(c) Follow the fault prevention recommendations as detailed in Section 8.2.

(d) The unit contains a pressurised refrigeration circuit. Do NOT attempt repairs on this circuitunless these are carried out by a qualified refrigeration engineer.

(e) If a filter is fitted to the fluid inlet line, it is essential that it is cleaned or replaced at least oncea month to prevent damage occurring to the pump.

(f) X-ray sources supplied by Thermo VG Scientific have a filter fitted to the top of the WaterBox. This filter should be checked and washed regularly.

.

Figure 7.5 - Filter Position on Water Box

7.7 Spare PartsThose parts, which due to wear and tear are more commonly required, are listed in the table asfollows.

PART NUMBER DESCRIPTION QTY020-03-002 Filament Assembly 1

833-05-016 Anode Assembly 1

020-03-003 Cathode Assembly 1

ALS075 Aluminium Foil 1

CUA19 Copper Gasket (Annealed) 1

CU38 Copper Gasket 1



XR501 Source Mounting Kit 1

Table 7.2- Spare Parts

F ilte r C o n d u it tos o u rc e

Fault Finding HA030012


8 Fault FindingWe hope that you experience the minimum of problems throughout the lifespan of the instrumentbut inevitably problems may occur. Problems that may have originated from other instruments, andother uses of the systems could contribute to a failure of the instrument. Any known problemsassociated with this type of instrument have been listed below with the possible cause andsuggestions to what to do. In some instances (marked *) it is recommended that the instrument isreturned to the factory for repair, see paragraph 3.2 for return of goods.

Prior to carrying out any fault finding and maintenance on the equipment, ensure the electronic unitsare disconnected and isolated from the mains supply.

8.1 Trouble Shooting / Fault FindingOBSERVATION POSSIBLE CAUSE REMEDY PARANo output from powersupply

Cable connections not made orincorrect

Fuse blown

Check all cable connections

Replace fuse on back of power supply(s)

5.5.1

4.6.2/4.7.2/4.8.2

No filament current Filament blown

Faulty power supply/cable

X-ray cable not connected

Filament current rises rapidly andsupply trips out

Disconnect filament cable and measurefilament resistance at X-Ray sourceReplace with new filament

Check continuity of X-ray cables fromconnection block at rear of X-ray powersupplies

Check connections at X-ray source from theModel 8732 unit.

Re-connect cable

Check for short to earth of filamentReplace or repair filament connections

7.4.2

4.7.2

5.5.1

7.4.2

HT failure Poor or missing earth connection

Dirt / Dust in Source

Faulty lead

Check earth connections are correct and tight.

Clean out Source *

Disconnect leads and check for breakdown

5.5.1

-

5.5.1Interlock failures Low water flow

Faulty water flow switch

Water LED indicator on front panel will notstay on. Measure water flow (min 3.0 l/min).

Rectify water flow problem, by increasing flowor removal of obstruction.

Check that the paddle wheel is turning.Check the in line output from the flow switch

5.3

5.3

4.9

Deterioration inPerformance ✫

Ageing of filament. Maximumattainable emission decreasing

Erosion or contamination ofanode, caused by running at highemission level when the vacuumchamber pressure is high.

Replace filament

Replace Anode

7.4.2

7.4.1

Table 8.1 - Trouble Shooting

* Factory repair is recommended for these actions

✫ The deterioration may be caused by one or more factors as listed above and it is difficult toascertain the required remedial action whilst the source is installed. The source should beremoved from the vacuum chamber and partially disassembled for inspection, (see section 7).

HA030012 Fault Finding


8.2 Fault PreventionIt is assumed that with a system in regular use and that the system was installed in a suitableenvironment and in regular use, faults will be repaired as they occur.

To maintain the equipment to the best operating conditions a maintenance schedule is suggestedas part of a fault prevention programme, the following items are suggested to be included in such aprogramme. The frequency of checking will depend on the usage of the equipment.

ITEM REGULARLY OCCASIONALLY

Isolate equipment and Inspect all cables and connectors forsigns of wear and that they are securely retained in position.

X

Check all control knobs are secure and operate correctly XCheck all interlocks are operating correctly XCheck all earthing cables and connections are secure XReduce water flow rate to check WATER interlock trips XCheck water flow is at least 3.0 litres/min X

Table 8.2 - Fault Prevention

Appendix HA030012


9 Appendix9.1 Appendix 1

RETURNED GOODS - HEALTH AND SAFETY CLEARANCEPart No.: ____________ Serial Number: _________Warranty ClaimDate delivered: _____________ Invoice No.: ___________ VG Order No.: ___________________________________________________________________________________ _Clean Components

This section to be completed if the equipment is not contaminated, if in doubt please fill in contaminatedcomponents section.

These goods have not come into contact with any toxic, hazardous or radioactive substances at any time.

Signed ...................................................... Position ..........................................................

________________ ________________________________________________________ _Contaminated ComponentsThis section to be completed if the equipment has been exposed to, or fitted onto a system which employs,ANY toxic or radioactive materials hazardous to human health.Important note: Thermo VG Scientific will not accept (for example) components for repair or credit whichhave been fitted to the growth chambers of MBE or CBE systems.Please list below all contaminants, including gases, any decontamination process employed and any cleaningmaterials used.If any potentially hazardous contaminants are noted on the certificate, please contact customer serviceat Thermo VG Scientific before returning the equipment.

Contaminants

The dispatch of any contaminated goods will be in accordance with the appropriate regulations covering packaging, transportation andlabelling of dangerous substances. I hereby declare that to the best of my knowledge the information supplied above is complete andaccurate.

Signed..............................................................................For (Company/Institution)...............................................................

Name:............................................................................... Address.................................................................……................

Position....................................................................................................................................................................................

Date.................................................................................

Telephone and fax......................................................................................................

PLEASE ATTACH ONE COPY TO THE OUTSIDE OF THE CONSIGNMENT. FAX ONE COPY TO CUSTOMERSERVICE +44(0) 1342 324613Procedure File Name: CC011.DOC 2nd May 2000 Issue 2 1 of 1

Copyright © Thermo VG Scientific 2000

Appendix 1 -Form CC011 - Returned goods - Health and Safety Clearance form

HA030012 Appendix


9.2 Appendix 2

Warranty Claim, Repairs and Returns Procedure

Warranty Claim

Electronic and basic servicing capabilities exist at most in-country Thermo companies and at appointedagents, however all components are sold with a return to factory warranty (unless otherwise stated)which covers failure during the first 12 months after delivery. Returns must be sent carriage paid,Thermo VG Scientific will cover the return carriage costs. This covers defects, which arise as a resultof a failure in design or manufacturing. It is a condition of warranty that equipment must be used inaccordance with the manufacturers instructions and not have been subjected to misuse. This warrantydoes not cover consumable items such as channeltrons, filaments and electron multipliers.To make a claim under the terms of this warranty provision contact the Customer Service Departmentat your local Thermo VG Scientific Representative in the first instance.

Chargeable Repairs

Always contact your in-country Thermo VG Scientific Representative in the first instance. They will bepleased to assist you and will be able to provide an estimate of repair costs, many offer local repairfacilities.Factory Repair Service. (Standard)For routine repairs where down-time is not critical. The target return time at Thermo VG Scientific isless than 30 days.

Returns

All returns to Thermo VG Scientific require the following procedure to be followed:

1. Contact the local Thermo VG Scientific Instrument Representative and request a ReturnsAuthorisation Number.

2. Complete a “Returned Goods Health and Safety” form and returned equipment fault report form,(appendix 1).

3. Attach a copy of the completed form to the outside of the package with the usual shippingdocuments.

Packaging and Carriage

All goods shipped to the factory must be sealed inside a clean plastic bag and packed in the originalcarton with the original packing inserts. Where a metal protective can was originally fitted this must beused, and backfilled if relevant. If the original packaging is not available Thermo VG Scientific should becontacted for advice. Thermo VG Scientific will not be responsible for damage resulting from inadequatereturns packaging or contamination of delicate structures by stray particles under any circumstances. Allnon-warranty goods returned to the factory must be sent carriage pre-paid, (Free Domicile). They will bereturned carriage forward (Ex-Works).

_____________________________________________________________________________________HK000102 2 July 1998 Issue 3 Page 1 of 1

Appendix 2 -Form HK000102A - Warranty Claim, Repair and Returns Procedure form

Appendix HA030012


9.3 Appendix 3

Returned Equipment Report

Returns Authorisation No.

Please list below each separate piece of equipment being returned, including part and serial numbers-

Item 1

Item 2

Item 3

Item 4

Item 5

Item 6

Item 7

Item 8

Item 9

Item 10

Please enter below the failure symptoms, and particulars of any rectification attempt made, in the fullestpossible detail -

Procedure File Name: CC009.DOC 03rd May 2000 Issue 2 1 of 1 Copyright © Thermo VG Scientific 2000

Appendix 3 -Form CC009 - Returned Equipment Report form

HA030012 Index


10 IndexAligning the Monochromator 38Aluminium Window 18Aluminium Window Replacement 43Appendix 50Appendix Contents 6

Bakeout 30

Cable Connections 33Chapter Contents 4Check Calibration of the Analyser 38Coarse Adjustment of the Monochromator 38Conformity 7Contact Information 14Contents 3Cooling Water 34Copyright Notice 3COSHH 7Crystal Manipulator Assembly 17Crystals 18

Degassing of the Monochromator 35Degassing Procedure 13Description 15Differential Pumping 29Disclaimer 8Dual Crystal Manipulator 42

Electronic Units 46E4870PR4 Water Chiller Recirculator 20E4870PR4 Water Chiller Maintenance 47Equipment 15Evacuation / bakeout 30

Fault Finding 48Fault Prevention 49Fine Adjustment of the Monochromator 39Fit Crystal Manipulator 32Fitting the Manipulator 42Flow Switch Assembly 26

Good Working Practices 12

Hardware Installation 28Hazard Labels used on Equipment 8Hazard Signal Words 8Hazard Signals and Signs 8Hazard to Operator 10Hazardous Materials 11Health and Safety 7

Illustrations 6Index 53Interlocks 20Introduction 14Installation 27Installation General 27Instrument Functionality Signs 9

Lower Leg Assembly 44

Maintenance - General Notes 41Maintenance 41

Manual Layout 3Micrometer Adjusters 42Model 8706 Connections 24Model 8706 Controls 23Model 8706 Power Supply Specification 16Model 8706 Power Supply 23Model 8706 Replacement 46Model 8732 Connections 22Model 8732 Controls 21Model 8732 Control Unit Specification 16Model 8732 Control Unit 21Model 8732 Replacement 46Model T-182/T-184 Connections 26Model T-182/T-184 Controls 25Model T-182/T-184 Power Supply Spec. 17Model T-182 or T-184 Power Supply 25Monochromator Start Up 40Monochromator Specific Safety Hazards 13Monochromator System 17Monochromator X-ray Gun Specification 16Monochromator X-ray Source 19

Notes 54

Operation 33Operators and Service Engineers 8Optional Items 15Overview 16

Personal Operational Risks 10Pipework 29Preparation 27Procedure Notes 34

Radiation Hazards 13Radiation Testing 35Removing the Manipulator 42Replacing the Mono Gun Anode 44Replacing the Electron Gun Filament 45Return of Goods 14Risk Analysis 10

Safety Interlocks 13Safety Policy 7Serious Damage to Instruments 10Servicing 8Shut Down 40Spare Parts 47System / Component Bakeout 31System Wiring 32

Tables 6Technical Specification 16Trouble Shooting / Fault Finding 48

Unpacking Checklist 27

Warning Labels used in Manuals 9Water 13

Notes HA030012


11 Notes

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