spx0 cavity and cryomodule systems wbs 01.02.01.03.05
DESCRIPTION
SPX0 Cavity and Cryomodule Systems WBS 01.02.01.03.05. Genfa Wu SRF Scientist ASD/RF SPX0 Review 23-24 August 2012. For the JLAB/ANL/SLAC Collaboration T eam. Outline. WBS Scope of this system Requirements Design Interfaces Risks considered (Fault Analysis) Summary. - PowerPoint PPT PresentationTRANSCRIPT
SPX0 Cavity and Cryomodule Systems
WBS 01.02.01.03.05
Genfa WuSRF ScientistASD/RF
SPX0 Review23-24 August 2012
SPX0 Review of the Advanced Photon Source Upgrade Project 23-24 August 2012
For the JLAB/ANL/SLAC Collaboration Team
Outline WBS Scope of this system Requirements Design Interfaces Risks considered (Fault Analysis) Summary
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SPX0 Review of the Advanced Photon Source Upgrade Project 23-24 August 2012
Cavity and Cryomodule System Scope
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Fabricate and test major cavity system components. Fabricate, test and install a single cryomodule containing two
SRF deflecting cavities (MARK II) with LOM/HOM waveguide dampers and tuners in Sector 5 of the APS storage ring.
SPX0 Review of the Advanced Photon Source Upgrade Project 23-24 August 2012
Cavity and Cryomodule System Requirements
Discuss requirements, PRD, ESD as exist. What KPP’s are supported (if applicable) Discuss the technical goals / science (if appropriate)
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SPX0 Review of the Advanced Photon Source Upgrade Project 23-24 August 2012
SPX0 Physics
To demonstrate operation of two fully-powered independently-controlled superconducting deflecting cavities with beam, including quantitative measurements of their impact on the beam. This test will require low-level rf control, high-power rf, interlock systems, timing and synchronization systems, cavity alignment, beam diagnostics, controls, and beam feedback.
To demonstrate synchronization of a beamline laser with the deflecting cavities at the sub-ps level.
When operated in phase, the two cavities will increase vertical beam size everywhere around the ring, and therefore in this configuration will not be compatible with normal user operation. The tests will only be conducted during storage ring beam study periods. When operated in opposite phases with zero net deflecting voltage, no significant effect on the beam is expected, so that the cavities could be operated and tested during user operations. However, this mode of operation will need to be confirmed as acceptable for the user operations first.
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SPX0 Physics Requirement Document
SPX0 Review of the Advanced Photon Source Upgrade Project 23-24 August 2012
SPX0 Main ParametersQuantity Value
Electron beam current 100 mA
Number of cavities 2
Total voltage 1.0 MV
RF Frequency 2815.486 MHz
Cavity tunability 200 kHz
Source tunability 1.5 kHz
Operating temperature 2 K
Longitudinal non-deflecting mode impedance <0.44 M-GHz
Horizontal non-deflecting mode impedance <1.3 M/m
Vertical non-deflecting mode impedance <3.9 M/m
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SPX0 Physics Requirement DocumentSPX0 Cryomodule Engineering Specification Document
SPX0 Review of the Advanced Photon Source Upgrade Project 23-24 August 2012
Cryomodule Engineering Specification* (1)
Cavity nominal operating deflecting voltage 0.5 MV with Q0 ≥ 1e9 Cavity Qext = 1e6, RF source 5 kW Cavity Tuner: 2815.486 MHz ±200kHz, resolution < 40Hz Cavity alignment:
– X : ±0.5 mm, Y : ±0.5 mm, Z : ±1.0 mm Cryomodule alignment:
– X : ±0.5 mm, Y : ±0.2 mm, Z : ±1.0 mm Cryogenic total heatload goal
– 2 K heatload < 50 W (+/-5 W)– 80 K heatload < 260 W
Profile needs to fit APS tunnel (Sector 5 envelop)– 73.4” flange to flange– Maximum height from beam line < 40” – Floor to beam < 52.52”
Advanced Photon Source Upgrade (APS-U) project
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*See Engineering Parameters Table for complete details
Cryomodule Engineering Specification* (2) Bellows
– Inter-cavity rigid connection– Warm to cold transition bellows
• Unshielded• Longitudinal movement ±0.5 mm, transverse movement ±1.0 mm
Magnetic shielding: ≤ 5 mili-Gauss Dampers
– External LOM load (2 kW)– Internal HOM load ( 500 W, water cooled)
Windows– LOM broad band, 5 kW average power– FPC broad band, 5 kW - 20 kW average power
Interfaces: water, vacuum, RF, instrumentation.
*See Engineering Parameters Table for complete details
Advanced Photon Source Upgrade (APS-U) project
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Deflecting Cavities
SPX0 Review of the Advanced Photon Source Upgrade Project, 23-24 August 2012
HOM Damper
LOM Damper
HOM Damper
CCA3 design
CCA3 fabrication
Input Coupler
Specification
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Deflecting Cavity Performance
SPX0 Review of the Advanced Photon Source Upgrade Project, 23-24 August 2012
CCB1 is fully satisfied to the spec
CCA2 achieved gradient requirement
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SPX0 Review of the Advanced Photon Source Upgrade Project, 23-24 August 2012
ls P
VR2
2
GHzMfR ps 44.0*
Stability Threshold
Monopole Impedance
Monopole Stability Threshold
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2
20
rkP
VR
l
rrt
mMRt /3.1
mMRt /9.3 Horizontal dipole
Vertical dipole
Dipole Stability Threshold
Vertical Dipole Impedance
Stability Threshold
Stability Threshold
Horizontal Dipole Impedance
Total HOM/LOM power for Mark-II: <0.5/1.8kW for APS 200mA, 24 beam bunch mode
Impedance Calculations for Single Cavity
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SPX0 Review of the Advanced Photon Source Upgrade Project, 23-24 August 2012
Impedance Calculations for Multiple Cavities
The propagating modes up to 5 GHz are also damped to meet the desire requirements. There is no trapped mode between the cavities.
Liling Xiao et al., Higher Order Modes Damping Analysis for the SPX Deflecting Cavity Cryomodule, IPAC 2012
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SPX0 Helium Vessel Design
SPX0 Review of the Advanced Photon Source Upgrade Project, 23-24 August 2012
Helium Return
Helium Supply
Tuner Attachment Points
Nitronic Rod Mount
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Stress Analysis of a Dressed Cavity
SPX0 Review of the Advanced Photon Source Upgrade Project, 23-24 August 2012
With the small bellows design, the peak stress in warm CC-A3 cavity dropped to 6,100 psi, which is below the allowable of 6,310 psi. (Conservative to design to peak stress.)
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SPX0 Tuner Design
SPX0 Review of the Advanced Photon Source Upgrade Project, 23-24 August 2012
SPX Tuner Design Specifications 12Gev Upgrade SPX
C100 Style CavityCC-A3
3.5mm wall
Tuning Sensitivity kHz / mm 310 9000Stiffness lbs / in 9851 170000
Deflection required for 200 kHz frequency shift
um 645 22
Force required for 200 kHz frequency shift lbs 250 149
Stepper Motor Resolution Steps/rev 200 800Harmonic Drive Ratio 100 100
Ball Screw Pitch mm/rev 5 2
Resolution from Stepper**full step Hz / increment 13.6 31.6half step Hz / increment 6.8 15.8
quarter step Hz / increment 3.4 7.9
Piezo Range(drive axis) um 60 60
(cavity axis) kHz 3.3 75.8Piezo Resolution
(drive axis) nm 0.13 0.13(cavity axis) Hz 0.01 0.16
* - SPX numbers taken from J. Liu FEA** - Stepper controller enables up to 1/256 microstepping. As smaller steps are used there is a tradeoff of resolution for torque. Testing is required to determine what level of micro-stepping is achievable.
Cavity Related Info*
Tuner Related Info
Tuning Range• +/- 200 kHz
Tuning Resolution• 40 Hz
Rapid Detuning• 3 kHz• < 1msec
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SPX0 Tuner Design Status: Cavity Measurements
SPX Cavity (CCA3-1) Exercised in Modified C100 Tuner Test Stand – Cavity instrumented with 4 strain gages– Axial Force, Length, and Frequency measured as
cavity stretched
SPX0 Review of the Advanced Photon Source Upgrade Project, 23-24 August 2012
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SPX Tuner Design Status: Cavity Measurements
SPX0 Review of the Advanced Photon Source Upgrade Project, 23-24 August 2012
Tuning Sensitivity (Mhz/mm)*
Cavity Stiffness (klbs / in)**
Predicted 12.2 113.5Measured 13.0 101.6
* - The tuning sensitivity with a He vessel is expected to decrease by 26%** - The stiffness with a He vessel is expected to increase by 12%
Modeling Validated
Horizontal Test Stand
18Advanced Photon Source Upgrade (APS-U) project
Horizontal cavity test 5 kW amplifier 50 W Cooling @2K Analog and Digital RF
Horizontal test of a dressed cavity is scheduled in October 2012
ATLAS test area
Advanced Photon Source Upgrade (APS-U) projectSPX Review, March 3-4 2011
19Advanced Photon Source Upgrade (APS-U) project
Cavity Layout for SPX0 Alignment
Advanced Photon Source Upgrade (APS-U) project
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One room temperature shielded beam line bellows each side (not shown)
Bellows adjustment and beam steering ranges
Advanced Photon Source Upgrade (APS-U) project
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Transition bellows allows +/- 0.5mm Beam line bellows allows +/- 1.0 mm Beam steering during beam studies allows +/- 0.66mm
If a cavity misses beam line by 0.5 mm, adjusting cryomodule alone can bring cavities back to perfect alignment of electric centers.
Adjustment bounding boxes
Alignment Progression
Advanced Photon Source Upgrade (APS-U) project
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1. Wire stretch on CMM allows relation of alignment balls to electrical center line of cavity
2. Comparison to pre-HV measurements provide reference
3. Create custom spool piece to link cavities and Use fiducials + wire stretch to confirm that pair electrical center matches combination of pair centers
4. Use alignment balls to transfer fiducialization from beam line to space from on rabbit ears
30 um error each time fiducialization transferred
Courtesy of Josh Feingold
1 2 3
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JLAB Stretched Wire Measurement
Advanced Photon Source Upgrade (APS-U) project
23Slide from Josh Feingold
Low Impedance Unshielded Bellows
Advanced Photon Source Upgrade (APS-U) project
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BellowsBunch length [mm]
Nominal loss factor Kloss [mV/pC]
Shielding
APS 3 64 YesSOLEIL 3 20 YesSPEAR3 3 67 YesNSLS-II 3 18 YesAmerican BOA IV
3 455 No
American BOA IV
10 1.517 No
Loss Factor: 1.517 V/nC
Prototype bellows are being fabricated
Materials: Copper plated Stainless Steel or Phosphor copper alloy
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SPX0 Review of the Advanced Photon Source Upgrade Project 23-24 August 2012
CLEAN ROOMCAVITY STRING
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SPX0 Review of the Advanced Photon Source Upgrade Project 23-24 August 2012
COLDMASS
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SPX0 Review of the Advanced Photon Source Upgrade Project 23-24 August 2012
COLDMASS
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SPX0 Review of the Advanced Photon Source Upgrade Project 23-24 August 2012
CRYOMODULE ASSEMBLY
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SPX0 Cryogenic Design
SPX0 will use existing CEBAF prototype end cans – No 5K circuit
• 5K heat load will be sunk to 2K with heat straps added to stabilize thermal loads as required (waveguides, beamtubes)
– Heat exchanger will be external to cryostat SPX0 will run with liquid dewars and vacuum pumping
– Goal - 2 K heat load for the cryostat is 50 watts– The vacuum pump planned for SPX0 has been measured at 64 watts at 23 torr (2.0 K)– If more pumping is needed there is an option to add additional pumping
Helium riser heat flux limit estimated by Gary Cheng– 98 watts at 2.0K, 59 watts at 2.07K
Thermal shield will use LN2 for SPX0– Will test at JLAB with ~50K helium
Heat load estimates do not include male bayonets and distribution system
SPX0 Review of the Advanced Photon Source Upgrade Project, 23-24 August 2012
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Cryomodule Heat LoadSPX0 Heat Load components 2 k Shield per per per per per perHeat loads per Item # Static Dynamic Total Total Static Dynamic Total Total
Cavity 2 7 14 0
HOM 4 1 1.3 2.3 9.2 0.37 0.72 1.09 4.36
LOM 2 1.36 0.21 1.57 3.14 12.05 0.35 12.4 24.8
FPC 2 1.14 0.48 1.62 3.24 5.09 0.45 5.54 11.08
Beam Tubes 2 0.14 0.16 0.3 0.6
Component Totals 9.28 20.90 30.18 35.8 4.5 40.24
Static Cryostat Estimate 12 12 144 144
Total 42.18 184.2
SPX0 Review of the Advanced Photon Source Upgrade Project, 23-24 August 2012
LOM
FPC
HOM
Beam pipe
Interfaces
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Director's CD-2 Review of the Advanced Photon Source Upgrade Project 11-13 September 2012
Cryogenic P&I D
Interfaces
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Director's CD-2 Review of the Advanced Photon Source Upgrade Project 11-13 September 2012
4 HOM dampers, 2 per cavity
Each HOM damper
(1) Water flows FI SPX 23
(1) Water temp ITQ SPX 23
(2) Heaters CHR SPX 23 & 23A
(2) T-couple (inside vacuum tank) ITQ SPX 23 A & B
Field probe outside of thermal shield RFP SPX 23
(2) diodes on vacuum waveguide CTD SPX 23A & 23B
Cavity P&I D
HOM as an example:
Cavity and Cryomodule Fault Analysis Summary (1) Accidental venting of beam line, insulating vacuum Cryogenic trip or power outage Helium circuit leak to insulating vacuum Helium circuit leak to beamline vacuum Cavity quench Window arcing Tuner failure Beam line valve failure Cavity performance degradation Excessive heating to 2K circuit Beam line mis-alignment greater than spec
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Director's CD-2 Review of the Advanced Photon Source Upgrade Project 11-13 September 2012
Cavity and Cryomodule Fault Analysis Summary (2) Cavity mis-alignment HOM load bonding failure HOM load SiC performance degradation HOM load water flow stops HOM load water leak in insulating vacuum space Excessive microphonics Field probe faults Cryogenic acoustic resonance
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Director's CD-2 Review of the Advanced Photon Source Upgrade Project 11-13 September 2012
Summary
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• SPX0 Design solutions have been developed• Cavity prototypes qualified• Prototypes of critical components are in progress
• Vertical alignment is critical• Low impedance bellows need beam test• LOM/HOM damping must be very strong
• Cryomodule design mostly completed, ready for procurement/fabrication
Director's CD-2 Review of the Advanced Photon Source Upgrade Project 11-13 September 2012