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SRF Vertical Test Cryostat Design Review

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Review outline. Location of and purpose of facility in IB1 (Joe Ozelis) ... ILCTA-VTC Design Review. 17. Integration with IB1 Refrigerator ... – PowerPoint PPT presentation

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Title: SRF Vertical Test Cryostat Design Review


1
SRF Vertical Test CryostatDesign Review
  • 16 May 2006
  • IB1

2
Introduction
  • Welcome and introductions
  • Charge to the committee
  • Assess the technical design of the ILCTA IB1 SRF
    Vertical Cryostat and its readiness for the
    procurement/fabrication process
  • Comment on all technical aspects of the Cryostat
    design, including integration to the IB1
    cryogenic system
  • Provide a written report.

3
  • not a facility safety review
  • Focus on
  • Cryostat technical specifications
  • Readiness for procurement
  • Review outline
  • Location of and purpose of facility in IB1 (Joe
    Ozelis)
  • Cryostat system requirements (Mayling Wong)
  • Integration with IB1 Cryogenic System, PID, and
    Cryogenic Design Parameters
  • (Roger Rabehl and Yuenian Huang)
  • 3D model overview (Clark Reid / Mayling Wong)
  • Documentation requirements (Mayling Wong)
  • Cost estimate, procurement plan, and schedule
    (Cosmore Sylvester)

4
  • Goals of the ILC Vertical Cavity Test Program
  • Verify cavity processing improvements by
    quantifying cavity performance in a reliable,
    reproducible, and efficient manner.
  • Measure Q0 vs Temperature
  • Measure Q0 vs E
  • Measure Field Emission (radiation)
  • Investigate effect of low temperature externally
    performed bakeout on Q-drop
  • Initial throughput expected to be 2
    cavities/month, increasing to 2 cavities/week.
    Multiple tests/cavity (Q-drop) increase this.
  • System is to be capable of testing cavities
    designed for the ILC Main Linac cryomodule.
  • Baseline Design Tesla cell shape, 9 cells, 1.3
    GHz. Alternate geometries, cells,
    superstructures, may also be evaluated.

5
Cavity Test Facility Location
6
Cavity Test Facility Location
Existing cryogenic services
Approx size/location of cryostat pit/hole
7
  • Cavity Test Facility Cryostat/Cryogenic
    Requirements
  • LHe bath capable of operation between 4.3 and
    1.6K
  • Cooldown rate from 300K to 4K that minimizes
    Qdisease susceptibility (minimize time spent
    between 100-150K)
  • Sufficient volume of LHe above cavity to preclude
    need for active LHe level control during testing
    (190-200cm 165cm to top cavity flange)
  • Instrumentation to provide readout of Dewar
    pressure, temperature, and LHe level
  • Fast turnaround
  • Cooldown fill 4-6 hours
  • Pumpdown 2-4 hours (can be concurrent w/ fill
    if not performing Q0 vs T measurements)
  • Remnant LHe boiloff 3-5 hours (150-180W for
    800L)
  • Warmup to 300K 10-12 hours (400K He gas at
    2g/s)

8
Example Test Cycle (w/ Q0 vs T measurement) Inser
t stand into Dewar Leak check Dewar seal Leak
check test stand Attach RF instrumentation
cables Pump/purge Dewar w/ GHe, check for
contamination Cooldown Fill _at_ 4K Cable
calibrations _at_ 4K Measure cavity frequencies (all
modes) Perform low field (2-3 MV/m) Q0
measurement (1W amplifier) Begin pumpdown to
1.5K, take low field Q0 data Warm back up to
2K Perform Q vs E measurements at 2K Boiloff
remnant LHe Warm Dewar
0.5hr 0.5hr 1hr 0.25hr 1hr 1.5hrs 4hrs 0.5hr 0.25h
r 0.5hr 3hrs 0.5hr 2hrs 4hrs 12hrs
Total warm-warm cycle time 31.5hrs
9
Example Test Cycle (w/o Q0 vs T
measurement) Insert stand into Dewar Leak check
Dewar seal Leak check test stand Attach RF
instrumentation cables Pump/purge Dewar w/ GHe,
check for contamination Cooldown Fill _at_ 4K, begin
pumping to 2K when LHE collects Cable
calibrations _at_ 2K Measure cavity frequencies (all
modes) Perform Q vs E measurements at 2K Boiloff
remnant LHe Warm Dewar
0.5hr 0.5hr 1hr 0.25hr 1hr 1.5hrs 4hrs 0.5hr 0.25h
r 2hrs 4hrs 12hrs
Total warm-warm cycle time 27.5hrs
10
Example Test Schedule (includes Q0 vs T
msmt) Day 1 Load test stand, all checkouts,
cooldown fill to 4K Day 2 Q0 vs T, Q0 vs E,
boiloff Lhe and begin Dewar warmup Day 3 Remove
test stand, setup for 120 C bake 24 hours Day
4 Load test stand, all checkouts, cooldown
fill to 4K Day 5 Q0 vs T, Q0 vs E, boiloff LHe
and begin Dewar warmup This scenario supports 2
tests per week of the same cavity, with a 24hr
120 C bake between tests. If Day 3 is a Friday,
can do a 48hr bake over a weekend.
11
Example Test Schedule (w/o Q0 vs T msmt) Day 1
Load test stand, all checkouts, cooldown, fill,
pump to 2K, Q vs E, start boiloff warmup script
(long day) Day 2 Remove test stand, setup for
120 C bake 48 hours, swap cavities Day 3
Load test stand, all checkouts, cooldown, fill,
pump to 2K, Q vs E, start boiloff warmup script
(long day) Day 4 Remove test stand, setup for
120 C bake 48 hours, swap cavities (baked
one) Day 5 Load test stand, all checkouts,
cooldown, fill, pump to 2K, Q vs E, start boiloff
warmup script (long day) This scenario
supports 3 tests per week, 2 different cavities,
one of which gets a 48hr 120 C bake between
tests.
12
  • Conclusions
  • The aggressive test schedules described here can
    be fully supported by a
  • cryostat/cryogenic system that provides
  • LHe bath capable of operation between 4.3 and
    1.6K
  • Cooldown rate from 300K to 4K that minimizes
    Qdisease susceptibility (minimize time spent
    between 100-150K)
  • Fast turnaround
  • Cooldown fill 4-6 hours
  • Pumpdown 2-4 hours (can be concurrent w/ fill
    if not performing Q0 vs T measurements)
  • Remnant LHe boiloff 3-5 hours (150-180W for
    800L)
  • Warmup to 300K 10-12 hours (400K He gas at
    2-4g/s)
  • The present design will be shown to meet these
    requirements.
  • Additionally, it does not preclude testing of
    alternate cavity designs or
  • more extensive (RD) testing.

13
Cryogenic System Requirements
14
Cryogenic System Requirements
15
IB1 Refrigeration Capability
  • Calculated cooling capacity of 125 W at 2 K.
  • Assumes 88-90 efficient J-T heat exchanger
    pre-cooling the supplied LHe. This HX is
    identical to one used in the MTF LHC quadrupole
    feed box.
  • Assumes 3 Torr pressure drop through the pumping
    line between the new test facility and the Kinney
    pumps.

16
ILCTA-IB1 Vertical Dewar PID
17
Integration with IB1 Refrigerator
  • LHe supplied across the roof of IB1 through the
    existing transfer line from the 10 kl dewar.
    Drawn off a phase separator, 5 K boiloff will
    cool a dewar intercept and a baffle.
  • GHe pumped away via Kinney pumps, returned
    directly to compressor suction, or vented to
    atmosphere. The first option requires a new
    pumping line, the last two options will use
    existing VMTF piping.
  • LN2 supplied from 10 kgal dewar, tying into
    existing VMTF piping.
  • GN2 vented to atmosphere, tying into existing
    VMTF piping.

18
Helium Vessel Thermal Design
  • Heat load to 2 K helium bath is controlled 80 K
    shield and heat intercepts at 80 K and 5 K level
  • 80 K shield and intercept will be cooled by LN2
  • 5 K heat intercept will be cooled by GHe vapor
    from phase separator, 10 W heater to control
    vapor flow
  • Heat load to 2 K from other sources (pumping line
    and instrumentations wired) will be estimated
    later, however, it should be around 2 W or so
    level

19
Helium Vapor Pressure Drop
  • The total vapor pressure drop will be about 3
    torr and thats our design goal
  • 2 line is 150 ft and 6 line is 300 ft
  • Total vapor pressure drop breaks down to three
    parts in the pumping line in our calculation
  • Pressure drop within JT heat exchanger, lt 1 torr
  • Pressure drop along 150 ft, 2 insulated piping,
    3.5 K inlet and 5 K outlet, the average pressure
    drop is 1.01 torr
  • Pressure drop along 300 ft, un-insulated 6
    piping, 5 K inlet and 300 K outlet, the average
    pressure drop is estimated to be 0.843 torr

20
Cryostat Layout
21
Helium Vessel
  • ASME BPVC vessel
  • Dimensions - 304SS shell
  • 28-inch OD
  • 0.094-inch thick
  • Thickness driven by external pressure (due to
    leak in insulating vacuum)
  • To minimize thickness ( conduction heat load)
    use Stiffeners every 30-inch along length
  • L1X1X1/4-inch angle bent intermittently welded
  • 16-feet long

22
Helium Vessel (contd)
  • Relief system
  • Burst disc
  • 65-psig set pressure
  • 1.5-inch - Sized assuming complete helium
    vaporization during leak of insulating vacuum
    (resulting flux of 0.6 W/cm2)
  • Code Relief valve
  • 50-psig set pressure
  • Connected to top plate of removable insert (not
    part of this assembly/procurement)
  • Heater for dewar warm-up
  • Temperature of helium 420K
  • Helium pressure 3-psig

23
Top flange of helium vessel
  • Thickness 1-inch
  • Sized to ensure welded joint to the helium vessel
    shell is adequate, following guidelines of ASME
    BPVC

Top flange of Helium vessel
24
Status of Documentation
  • Engineering drawings
  • 75 exist for initial design iteration
  • Engineering notes
  • Helium vessel 75 complete
  • Vacuum vessel
  • Pressure drop calculations
  • Heat load analysis
  • Relief valve sizing
  • Technical specification for vendor (required at
    the time the RFP is issued)

25
Cost Estimate
26
Procurement Plan
  • Complete the Design of the Cryostat assembly and
    release via. an RFP. Select the best qualified
    vendor based on a technical evaluation of the
    vendors proposal - not solely on lowest bid.
  • While cryostat Procurement is underway-
  • Continue to work towards a final design of the
    magnetic shielding and release these drawings for
    fabrication (estimated del 6 weeks ARO)
  • Continue to work on the final design of the top
    plate and suspension components and then release
    these for fabrication
  • located a supplier of the Lead and has a quote
    and estimated delivery (6 weeks ARO)
  • located a supplier for an encapsulant (rated for
    4.5K use) which could be used on the exposed lead
    surfaces

27
Schedule
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