Radial Ion Pump, BPMs, & Radial Ion Pump, BPMs, & HOM BellowsHOM BellowsRadial Ion Pump, BPMs, & Radial Ion Pump, BPMs, & HOM BellowsHOM Bellows

Machine Advisory Committee MeetingMachine Advisory Committee MeetingDecember 14, 2004December 14, 2004

Nadine KuritaNadine Kurita

Machine Advisory Committee MeetingMachine Advisory Committee MeetingDecember 14, 2004December 14, 2004

Nadine KuritaNadine Kurita

PEP-II Vacuum p2

Radial Ion PumpRadial Ion Pump

Beam Position MonitorsBeam Position Monitors

HOM BellowsHOM Bellows Q4/Q5 Bellows + absorber

Straight HOM Bellows

Q2 HOM Bellows

OutlineOutline

PEP-II Vacuum p3

Contributers/ Upgrade StaffContributers/ Upgrade Staff

PhysicistsPhysicists Michael Sullivan

John Seeman

Stan Ecklund

Sasha Novokhatski

Stephen Weathersby

Cho K. Ng

Artem Kulikov

Uli Wienands

DesignersDesigners Ho Dong

Manual Trigos

Michael Kosovsky

EngineeringEngineering Nadine Kurita

Dan Wright

PEP-II Vacuum p4

B1 Radial Ion PumpB1 Radial Ion Pump

Pump modeled after Pump modeled after PEP-I, SPEAR and the PEP-I, SPEAR and the Damping Ring. Damping Ring.

Detail design of cell Detail design of cell arrays engineered by C. arrays engineered by C. Perkins 1998.Perkins 1998.

PEP-II Vacuum p5

B1 Radial Ion PumpB1 Radial Ion Pump

Prodec Anode cell structure

Tantalum Cathode Plates

Ceramic Standoff

2mm holes

Baffles

Modified to Ta from Ti to increase noble gas pumping and eliminate the argon instability.

Additional BPM set

Reduced to 4 cell arrays from 6.

Shorten pump to add BPM set.

PEP-II Vacuum p6

B1 Radial Ion PumpB1 Radial Ion Pump

Create two independent pumping cells

Pro: if a cell fails you still have another operational unit

Con: you are 2 times as likely to have a failure.

Standard pump feedthrough

Current feedthrough rated fo 6 kV

Pump operates at 5.5 kV

Standard feedthrougs rated for 12 kV, 10A

PEP-II Vacuum p7

B1 Radial Ion PumpB1 Radial Ion Pump Pump cell array is Pump cell array is

unchanged unchanged Cell diameter optimized

for pumping speed and operating pressure

.36 cm for a Penning cell in a 15 kilogauss field at 1 x 10-9 Torr pressure.

Speed versus diameter curve is flat above .2 cm so the hole size is driven by manufacturability.

2:1 cell height to cell diameter ratio gives optimum surface coverage for sputtering on the anode.

.48 cm Need to review depth

PEP-II Vacuum p8

Ion PumpIon Pump

Holes & baffles unchanged .094” x .245 deep

Baffles to prevent SR from striking anodes or cathodes.

No direct line of sight

PEP-II Vacuum p9

Ion Pump MilestonesIon Pump Milestones

Final Design Review 1/05Final Design Review 1/05

Order long lead items 1/05 Order long lead items 1/05 Tantalum plates

Complete piece detail part drawings 3/05Complete piece detail part drawings 3/05

Receive piece parts 5/05Receive piece parts 5/05

Assemble, bake 7/05Assemble, bake 7/05

PEP-II Vacuum p10

Beam Position Monitor (BPM)Beam Position Monitor (BPM)

Upgrade improvementsUpgrade improvements Added BPM set at each radial ion pump. The new set is separated in z by ~f * 7.9 cm from the

BPM’s in the B1 chamber, where f = 2. 7.9 cm corresponds to a quarter wavelength of 952

MHz, the BPM procesing frequency. In the electronics they can then synthesize independent

linear combinations of the signals which correspond to the two beams moving in opposite directions.

~2*7.9

PEP-II Vacuum p11

Q4R looking downbeam

e-

Q5L looking downbeam

e-

BPM’s in Replacement ChambersBPM’s in Replacement Chambers HER Q4 & Q5 ChambersHER Q4 & Q5 Chambers

Located at the outboard end of Q4 and outboard end of Q5.

Use spare PEP-II BPMs for Al chambers (LER arc style).

PEP-II Vacuum p12

Improvements HER Q4/Q5 BPM’sImprovements HER Q4/Q5 BPM’s Bellows allows the Q5 BPM to be rigidly

supported (xx, y z). Q4 BPM is held in x, yy

Greater thermal stability Lowered thermal gradients

Support BPM to Quad magnet

No calibration required – QMS/BBA

BPM’s are centered on the beam in the x-direction,

BPM center to BPM center x- spacing determined by (R. Johnson, S. Smith (2004).

Place BPM’s on flat surfaces.

PEP-II Vacuum p13

BPM’s (cont.)BPM’s (cont.)

SparesSpares HER Arc Style (CuNi Housing) – 3 units

LER Arc Style (Tin seal housing) – 44 units

Straight Style (SS Housing) – 2 units

Total quantity neededTotal quantity needed Radial ion pump – 8

HER Q4/Q5 – 16

LER Q4/Q5 – 16 Could use LER Arc Style, but HER Arc style preferred

Total 44 BPM’s Equals spare quantity of LER arc style

No loss of units, no additional sets if possible

PEP-II Vacuum p14

BPM HistoryBPM History PEP-II - purchased alumina borosilicate glass feedthroughs PEP-II - purchased alumina borosilicate glass feedthroughs

from Kaman Instrumentation. from Kaman Instrumentation.

~2002 Meggit Safety Systems purchased Kaman ~2002 Meggit Safety Systems purchased Kaman Instrumentation.Instrumentation.

2003 Meggit produced spare BPM's for SPEAR3 2003 Meggit produced spare BPM's for SPEAR3 XPS analysis shows product to be incompatible with vacuum.

~2002 Times Microwave starts up a new division with the ~2002 Times Microwave starts up a new division with the Kaman engineers to produce borosilicate connectors and Kaman engineers to produce borosilicate connectors and feedthroughs. feedthroughs.

Times has no rights to our PEP-II or SPEAR3 design.

New process and ceramic to produce the seal. This technology is better for vacuum cleanliness, but we have no history on the integrity of the seal.

~2004 Bejing receives BPM's from Times that leaked after ~2004 Bejing receives BPM's from Times that leaked after welding. welding.

PEP-II Vacuum p15

BPM Vendor SelectionBPM Vendor Selection MeggitMeggit

Pros: They have detailed drawings and procedures to fabricate our BPM's.

Cons: They are not as responsive as Kaman was. Cons: They have not successfully built a clean vacuum component.

TimesTimes Pros: They have the original engineers that helped develop the PEP-II

BPMs. Pros: They are responsive. Cons: Unproven design and manufacturing of the seals. We would

require R&D funds to validate their sealing technology and connector reliability.

Cons: It would be beneficial to develop another company that could produce BPM's for the lab in the future.

Cons: Long term viability of the RF instrumentation division.

PEP-II Vacuum p16

BPM Future TasksBPM Future Tasks

Clean the Meggit SPEAR3 BPMs with a non-Clean the Meggit SPEAR3 BPMs with a non-corrosive solution, bake and RGA scan. corrosive solution, bake and RGA scan.

Re-develop with Times a comparable BPM's. Re-develop with Times a comparable BPM's.

These BPM's should be electrically identical to These BPM's should be electrically identical to the PEP-II BPM's and they must meet our the PEP-II BPM's and they must meet our technical specification. technical specification.

Testing per the SLAC specification

Estimated lead time for fabrication is 10 weeks Estimated lead time for fabrication is 10 weeks from Times. Potentially longer lead time for from Times. Potentially longer lead time for Meggit.Meggit.

PEP-II Vacuum p17

Q4/Q5 Bellows & AbsorberQ4/Q5 Bellows & Absorber

Major RequirementsMajor Requirements HER: 2.2A, 9Gev

Beam stay clear 12 + 0 mm in X

9 + 0 mm in Y

Luminosity Cone : 6.24

Synchrotron Radiation No SR power strikes the bellows module

Mis-steer RF fingers protected by chambers

± 1 mrad in X – requirement

± 2 mrad in Y – requirement

Forward > 5 mrad

Backward > 25 mrad

HOM power, Scattered SR, Ohmic Engineering estimate: 1 KW/m

PEP-II Vacuum p18

Q4/Q5 Bellows Requirements (cont.)Q4/Q5 Bellows Requirements (cont.)

Modular Design – 4.25” Operating Temperatures

Tmax Finger < 100ºC 500 C @ 10 hrs w/ minimal stress relaxation

0ºC - 100ºC, Installed 200ºC Bake Out, Manufacturing

Chamber Operating Temperatures Cold Day 0C ~Tave = 45C

Allows for misalignment and manufacturing tolerances of mating chambers.

Allows for thermal expansion of mating chambers. Installation space for chambers. Load bolts from bellows.

Space is tight – may need to remove corrector

PEP-II Vacuum p19

Q4/Q5 Bellows LayoutQ4/Q5 Bellows Layout

Q4 side, 10” Q4 side, 10” flangeflange

Q5 side 12” flangeQ5 side 12” flange

GlidCop GlidCop StubStub

Inconel Spring Inconel Spring FingerFinger

GlidCop RF GlidCop RF Shield FingerShield Finger

Welded Welded BellowsBellows

Cooling – not shownCooling – not shown

Absorbing TileAbsorbing Tile

PEP-II Vacuum p20

Q4/Q5 Blws Detail DesignQ4/Q5 Blws Detail Design

HER Arc Bellows concept with HER Arc Bellows concept with absorberabsorber

Ensure failure does not result in Ensure failure does not result in the RF shield falling into beam the RF shield falling into beam tubetube

Shield fingers slide on outside of chamber stub

Keep high stress areas away Keep high stress areas away from high heat areasfrom high heat areas

Keep steps to a minimum, Keep steps to a minimum, reduce impedancereduce impedance

Plating to minimize wear, Plating to minimize wear, decrease cold welding, solid decrease cold welding, solid lubricationlubrication

PEP-II Vacuum p21

Q4/Q5 Blws ApertureQ4/Q5 Blws Aperture

SR passes both SR passes both directionsdirections

Stub can’t protect thin RF shield fingers

Backward side Mask on chambers protect

bellows from large misteers

Forward side Chamber walls protect bellows

from 5 mrad misteere- Forward

e- Backward

.080 step at stub

BSC grows in Q5BSC grows in Q5

No taper – step at stub No taper – step at stub onlyonly e+ Backward

PEP-II Vacuum p22

Q4/Q5 Blws - AbsorberQ4/Q5 Blws - Absorber

Three options for absorber Three options for absorber placement.placement.

#1 - Directly above RF shield fingers

#2 - Above the Spring Fingers #3 - In the bellows cavity space

Tile is located in the HOM cavity Creates another vacuum joint Makes GlidCop stub a mechanical

braze & not a vacuum braze. Latest design uses option #3.

All options probably absorb the trap mode between the RF shield fingers and the welded bellows

Sasha/Stephen have a model of option 1. Option 3 next week.

Option 1

Option 3

PEP-II Vacuum p23

Q4/Q5 Blws - Absorber AnalysisQ4/Q5 Blws - Absorber Analysis Tile Tile

Actual size and quantity TBD. Engineering evaluation assumes optimal tile volume.

Size .4 x .47 x .5

14 tiles in module

Ceralloy 13740 K = 30 W/m-C

Flexural strength 43.5 ksi

HOM powerHOM power 2 KW assumed

Ansys ResultsAnsys Results Tcool = 51C Tmax tile = 240C

tile z25 ksi

ANSYS 8.0DEC 7 200423:11:45PLOT NO. 2NODAL SOLUTIONSTEP=1SUB =1TIME=1TEMPTEPC=12.673SMN =33.436SMX =240.263

1

MN

MX

X

Y

Z

33.43656.41779.398102.378125.359148.34171.321194.301217.282240.263

Q4Q5 Bel R4, Ceralloy 13740, h=1.5, tb=30, qtot=2kw

PEP-II Vacuum p24

HOM Absorbing HOM Absorbing BellowsBellows

PEP-II Vacuum p25

HOM Absorbing BellowsHOM Absorbing Bellows

New bellows designs that also function as New bellows designs that also function as beamline HOM absorbers.beamline HOM absorbers.

LER arc bellows

Straight bellows

Q2 bellows

New bellows designs that have absorbers that New bellows designs that have absorbers that protect themselves from modes that leak behind protect themselves from modes that leak behind their RF shields.their RF shields.

Vertex bellows

Q4/Q5 bellows

PEP-II Vacuum p26

Straight HOM Blws -Design DetailsStraight HOM Blws -Design Details

GlidCop GlidCop StubStub

Inconel Spring Inconel Spring FingerFinger

GlidCop RF GlidCop RF Shield FingerShield Finger

Welded Welded BellowsBellows

Absorbing TileAbsorbing Tile

2.75” long by .24” wide 2.75” long by .24” wide HOM Trapping SlotsHOM Trapping SlotsModes in the chamber propagate through the slots & are absorbed by the AlNiSiC.

Bellows CavityBellows Cavity

Modes that leak past the RF shield finger and are trapped in this area still see the absorber

PEP-II Vacuum p27

Straight Section HOM BellowsStraight Section HOM Bellows

Prototype of the HOM absorbing bellowsPrototype of the HOM absorbing bellows Simple round geometry

Locate near isolation valves to tests its impact on HOMs in neighboring components.

Conceptual design near completionConceptual design near completion

HOM calculations are being done to optimize tile HOM calculations are being done to optimize tile size and slot dimensions.size and slot dimensions.

Initial HOM analysis shows that the concept Initial HOM analysis shows that the concept works.works.

Reduces monopole absorption while optimizing dipole and quadrupole field absorption.

PEP-II Vacuum p28

Near IR LayoutNear IR Layout

PEP-II Vacuum p29

Q1/Q2 HOM BellowsQ1/Q2 HOM Bellows

FY2003 added 4 layers of tiles per module.FY2003 added 4 layers of tiles per module. Absorbing ~10 KW presentlyAbsorbing ~10 KW presently Predict ~ 50 KW in 2007Predict ~ 50 KW in 2007 Numerous iterations on HOM absorbers Numerous iterations on HOM absorbers

have been analyzed by S. Weathersby and have been analyzed by S. Weathersby and A. Novokhatski (A. Novokhatski (38 runs38 runs). ).

Goal: Create a HOM absorber that doesn’t generate ~50% of its absorption power.

Reduce monopole without significantly reducing dipole and quadrupole modes

Most effective design requires at minimum 4” slots as in the Straight HOM Bellows.

The optimized design for various modes must be chosen by February 2005.

A few more design/analytical iterations will be performed Reduce power absorption, but still reduce HOM power at

the vertex ends, vertex bellows and radial ion pump. Vertex bellows will have HOM tiles Gold plating will be extended on the vertex ends.

PEP-II Vacuum p30

Q1/Q2 Blws - HOM AnalysisQ1/Q2 Blws - HOM Analysis

4” long tile sets4” long tile sets Suppresses the monopole mode

without reducing the dipole and quadrupole mode

Sasha calculated the set back of the tiles

Focusing on 2” long tile setsFocusing on 2” long tile sets Reasonable length for the 5” bellows

module

PEP-II Vacuum p31

Q1/Q2 Blws - Design StatusQ1/Q2 Blws - Design Status New concept New concept

developed developed based on best

information available.

Maximum Maximum Tile/slot lengthTile/slot length

~2.4”

Absorbing tiles Absorbing tiles is open to the is open to the convolutionsconvolutions

No additional tile set needed in bellows cavity.

HER Arc Style HER Arc Style Bellows Bellows

Spring

Stub

RF shield

Possibly reduce further the travel and offset requirements to increase length.

PEP-II Vacuum p32

Q1/Q2 Blws - Major MilestonesQ1/Q2 Blws - Major Milestones

Finalize Physics/HOM Reqs Finalize Physics/HOM Reqs Feb ’05Feb ’05 Conceptual Design ReviewConceptual Design Review Mar ‘05Mar ‘05 Final Design ReviewFinal Design Review Apr ‘05Apr ‘05 Long Lead Procurements Long Lead Procurements Apr ‘05Apr ‘05 Detail Drawings CompleteDetail Drawings Complete Jun ‘05Jun ‘05 Receive PartsReceive Parts Aug Aug

‘05‘05 Final AssemblyFinal Assembly Sep ‘05Sep ‘05 Ready for installationReady for installation Sep ‘05Sep ‘05