http://indico.cern.ch/event/373053/

Beam Instrumentation during LS1Ray Veness on behalf of the BE/BI group

Ray Veness, BE-BI 2

Overview

• Introduction• Activities around the beam lines• Non-beam vacuum activities• Overview of main issues

• Safety• Interactions with other groups and services • Scheduling• Resources in BI• Towards LS2• Conclusions

Ray Veness, BE-BI 3

Instruments Removed during LS1

• Typical activities• Participation in CERN-wide activities (eg, SMACC, LSS1

cabling, layout changes)• Consolidation and maintenance of instruments (eg, impedance

issues in LHC-BSRTM, fatigue lifetime in LHC-BWS)• New or replacement instruments (eg, SPS-BWSRE, LHC-BGV)

Machine Complex

In-Vacuum Beam Instruments

Non-Vacuum Beam Instruments

Total in place Removed Total in place Removed

PS 457 87 109 159

SPS 496 63 410 30

LHC 1220 73 3993 2300

Total 2173 223 4508 2489

Ray Veness, BE-BI 4

LHC Beam Loss Monitoring System

• More than half of the 3989 ionisation chambers removed and replaced for SMACC and other interventions

• 834 chambers re-located with new supports

• All re-calibrated with radioactive sources• More than 70 km of new cables installed• Exchange of tunnel and surface electronics

racks• Effective participation from a Russian

collaboration team

5

BLM Relocation for UFO Detection• BLM system designed to protect from

beam losses at maximum-beta locations (quadrupoles)

• During Run1 there were 3 BLMs per beam per Quadrupole

• Middle BLM moved to main dipole interconnect in order to protect efficiently from UFO losses• Gain a factor 30 in sensitivity

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Synchrotron Light Extraction Mirror (BSRTM)

Mirror heating clearly correlated to

• beam intensity• beam spectrum• bunch length

Failure of mirror holder + blistering of mirror coating

Metallic mirror holder + Silicon bulk mirror

Complete Re-design• EM Simulations• Lab Measurements

Metallic holderSilicon bulk mirror

BeamSR

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Synchrotron Light Extraction MirrorOLD Extraction Mirror

NEW Extraction Mirror

Solution for Run II with low RF ‘footprint’ and shielded cavities

The Challenges of LHC Operation at 7TeV 8

The Beam Gas Vertex Detector (BGV)• Prototype installed on one

beam during LS1• Detectors based on

scintillating fibres read out with SiPMs

Rhodri Jones @ IBIC14 – 17/9/2014

• LHCb (CERN)• EPFL (CH)• Aachen (DE)

Ray Veness, BE-BI 9

(Examples of) LS1 non-Beamline Activities

• Temperature controlled racks for LHC BPMs and BLMs• Some 45 new racks in surface buildings with 150

crates• EN-CV were an essential partner

• New beam position system infrastructure in the SPS (MOPOS project)• 100’s of Km’s of optical fibres pulled by EN-EL

• New controls infrastructure• Installation and commissioning of 100+ front-end

computers• DOROS (Diode ORbit and OScillation) project

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LHC Orbit Stability Improvements• Planned improvements

• Thermalised racks• Maintains temperature within

±0.2°C• Implementation

• 45 new racks with 150 crates• Cooling system from EN-CV

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Ray Veness, BE-BI 11

Overview of main issues

• Categories of interventions• Interventions for CERN-wide projects, changes of layout etc:

• Generally worked well as they were clearly defined and planned in advance

• New prototypes (eg,BGV, BWSRE)• Working on ‘best effort’ basis reliant on other (overloaded) services• BI worked with MEF and committees (eg, LMC) to closely follow priority

and schedule

• Interventions where the solution to the problem was not clear at the start of the shutdown, or the problem was discovered during the shutdown• Changes in accelerator operating parameters or instrument impedance,

vacuum, performance) caused most problems (BWS, BQS, BSRT)• These are not possible to plan in advance as the effort required is not

known

Ray Veness, BE-BI 12

Safety• Radiation Protection

• Statistics• Highest individual dose 1.7 mSv for the 2-years of LS1, • Integrated group dose 37.0 mSv, or an average of 0.29 mSv per BI film badge holder

(Staff+MPA+FSU)• Radioactive transports

• Approximately 600 radioactive transports from BI during LS1• All radioactive labs now in B.867 (Prevessin), but the only workshop is B.109

(Meyrin)• B.109 proved sufficient during LS1, but a radioactive workshop in B.867 would

reduce radioactive transports between sites• Mechanical safety

• No serious incidents, one minor accident• Access

• IMPACT, biometry, MADs, TREK all take time for the equipment groups• Introduce new rules and procedures at least 6 months before a long shutdown• Ensure good communication and training for changed procedures/tools

• Safety training good

Ray Veness, BE-BI 13

Interactions with other groups and services I

• MME• Design activities: Weekly meetings made this work well• Metallurgy - Essential for diagnosing problems: Worked well• Manufacture: Quality good, but overloaded, in particular EB welding, metrology.

• Propose: On-line tool for tracking progress of manufacture jobs. • Propose: Increased capacity and preventive maintenance for key technologies

(eg. EB welding) and resources for metrology during LS2• EL

• Discussed in detail during the recent EL review – specific comments on stores and catalogues

• EL were vital to success in several projects – flexibility much appreciated• Early discussions on what could and could not be done allowed BI to re-direct

manpower to other projects• TE/MPE-EM Electronics Modules

• This service was also heavily loaded during LS1 and follow-up proved difficult• Propose: on-line production tracking and regular meetings as with MME

Ray Veness, BE-BI 14

Interactions with other groups and services II

• This is key for BI scheduling: acceptance testing is by definition on the critical path as it must be the final activity on the completed instrument• A number of causes identified, working with VSC to improve this for LS2

• Resources are limited for the VSC-managed 40-30 leak detection contract: • Early discussions on expected workload early to ensure resources are planned

• Survey, transport• Relies on professional contacts, which work well• EDH transport tools worked well

Machine Complex # Vacuum Acceptance Tests

# Failure on First Test

Success Rate

PS 54 20 63%SPS 24 11 54%LHC 44 14 68%Total 68 25 63%

• VSC• Statistics for vacuum acceptance test acceptance was lower than expected throughout LS1

(see below)

Ray Veness, BE-BI 15

Scheduling• BI appreciated the strong, pro-active planning team• Several issues at the start of LS1:

• BI lost time during the first months as interventions were not ready to start• For LS2, we need to start our follow-up meetings several months before the

shutdown• There was a lack of cohesion between LHC and injector schedules for the first

months of the shutdown• This was fixed during LS1 – and should be strengthened for LS2

• The situation improved significantly as LS1 progressed.• Including planners and machine superintendents in the relevant BI coordination

meeting helped - propose to integrate a planner in BI for LS2• Should consider the most efficient format for machine planning meetings

• Some projects inherently on critical path for ALARA reasons (SPS-LSS1, TCCD…)• BI instruments are nearly all considered a high priority for the operations team

• Took advantage of LS1 to work on a long list of maintenance and improvement• A project is under way with OP to prioritise spares for operation

Ray Veness, BE-BI 16

Resources in BI

• Phased closure (PSB-PS-SPS-LHC) meant that experts were commissioning one machine whilst still making interventions in the others• This resulted in less than optimal presence in the CCC

• BI need to resource-level across ‘shutdown’ and ‘start-up’ – meaning less time available for LS2 interventions

• Many key staff were committed ~100% for LS1• This had an impact on other projects (LIU, ISOLDE…)• BI committed extra resources to EL and 40-30 to unblock bottlenecks

• These additional constraints need to be minimised, but planned where necessary

• Relied on availability of external collaboration personnel (eg. Russian team for BLMs) and FSU• This worked well, and will be repeated in LS2

Ray Veness, BE-BI 17

Looking towards LS2

• LS2 fully focusses on older, more radioactive injectors• BI inventory includes some 130 spare monitors in

radioactive storage• These must be re-checked and validated with VSC, or re-

designed/re-procured• Experience in the SPS (particularly NA) was that cables are

radiation damaged, making them brittle and often need replacing

• Change to long operating periods means a backlog of basic maintenance must be included in the schedule

• BI consolidation project (BOSS) to identify high-priority instruments and procure critical spares is underway, but this is planned to take a number of years

Ray Veness, BE-BI 18

Conclusions• 99.5% of the original baseline work was completed, and more things besides

• Baseline, core activities generally went smoothly (eg, BLM, BTV, BCT, LSS1, North Area consolidation)

• Issues arose mainly where a problem was not identified or understood before the shutdown (eg, BQS, LHC-BWS), or with pre-identified ‘best effort’ projects (eg, BGV, BWSRE)

• Working closely with MEF later in the shutdown helped the few critical late items• BI activities span all machines, experimental areas and transfer lines,

• LS2 needs global scheduling for all complexes, not neglecting the overlap between shutdown and commissioning in different machines

• Looking forward to LS2, BI already has a long list of high priorities• Need to target the top priorities for CERN, identify critical instruments and prepare

spares where budget allows – PLAN worked for LS1 and could be improved for LS2• Closer follow-up of progress, not only with MEF but also CERN services such as

mechanical and electronic design and manufacture• Be prepared to start activities as early as possible, and identify possible areas to

postpone if required

…to all the people, groups and services who helped make this

shutdown a success for BI

THANKS!

Ray Veness, BE-BI 19