# Presentation: 453746

## Design Status of Fermilab SRF Cryomodules

- 3.9 GHz (for DESY)
- &
- TTF III+ (kit from DESY)
- &
- FNAL Generation III+
- &
- ILC T4CM
- Don Mitchell, FNAL
- January 11, 2006

## 3.9 GHz Cryomodule for DESY

- Don Mitchell, FNAL

## 3.9 GHz Cryomodule Design

- Design effort currently on cavity processing and testing fixtures.
- Effort will then focus on completing the following design details: helium vessel, bladetuner, magnetic shields, and misc. coldmass components; all of which are at the 90% - 95% level of completion

- Don Mitchell, FNAL

## TTF III+ is our design referencefor ALL 1.3 GHz Cryomodules

- Don Mitchell, FNAL

## TTF III+ Cryomodule

- Build kit to be sent by DESY to Fermilab (NO Quad magnet!)

- Don Mitchell, FNAL

## Americanized TTF III+ Cryomodule

- Virtually the same as TTF III+, detailed in metric but drawn for American vendors. This is all part of the American Industrialization plan.

- 2nd Cryomodule fabricated in the U.S. (NO Quad magnet!)

- Don Mitchell, FNAL

## Americanized TTF III+ (cont.)

- Work has begun on:
- Cryostat Vessel
- Cavity
- Helium Vessel
- Main Couplers

- Work _not_ started:
- HOM Antennas
- Coldmass components
- Coldmass supports
- Vacuum system
- Support Stand

- Current work stoppage while the 3rd Harmonic project is being finished.

- Don Mitchell, FNAL

## ILC Design Considerations

- Move quad package to middle of cryomodule to achieve better support and alignment.
- Shorten cavity-to-cavity interconnect and simplify for ease of fabrication and cost reduction. Possible superconducting joint.
- Minimize direct heat load to cavity through MC.
- Simplify the assembly procedure.
- MLI redesign to reduce hands-on labor costs.
- More robust to survive shipping.
- Reliability of tuner motors in cold operation.
- Etc. (we’ve heard many suggestions)

- Don Mitchell, FNAL

## Slide 9

- Don Mitchell, FNAL

## ILC Generation 4 (not the final ILC design)

- Small changes to address major concerns.
- Magnet alignment and vibration issues.
- Cryomodule with and without magnet pkg.
- Possible option for separate magnet cryovessel

- Current Cryo3

- Don Mitchell, FNAL

## Slide 11

- Don Mitchell, FNAL

## Slide 12

- Don Mitchell, FNAL

## T4CM Proposed Cavity w/ Bladetuner

- Don Mitchell, FNAL

## Slide 14

- Don Mitchell, FNAL

## Generation 4, T4CM

- Don Mitchell, FNAL

## Proposed 4th Generation Design

- 2 Vessels, Δ 1293.8 mm in length (w & w/o Magnet package)
- Cavity string supported and aligned by 3 support posts.
- Magnet independently aligned but still supported from the 300mm HGR pipe. (HGR Pipe may need to be resized)
- Support post locations may be identical in both vessels to simplify the tooling.
- HOM absorber in interconnect region.
- Smaller cav-to-cav connection (71.8mm)
- BPM, Quad magnet, and steering magnets are combined into onemagnet package. Total length currently assumed to be 1222 mm.
- TTF III cavity utilizes short end-tube for both ends. Length reduced by 37mm.
- Possible use of Bladetuner due to the shortened cavity length.
- New Magnetic Shield design.
- All ports and flanges will be metric and ISO style.

- Don Mitchell, FNAL

## T4CM will differ from Type III+ in the following general areas

- Cavity iris-to-iris spacing reduced to 283 mm
- Reduces length from 12.20 to about 11.8 m, get ~0.75 packing (but increased magnet length negates this save in overall length, in fact, making T4CM 356.4 mm longer)
- Slow tuner modified to allow closer cavity-to-cavity spacing (could mean switching to bladetuner design, but choice still open)
- Fast tuner -- new design
- Quad/corrector/BPM package under center post, hung from 300 mm tube, not on rollers (diverging from X-FEL)
- Two major module types, one with quad and one without

- Don Mitchell, FNAL

## More differences of T4CMfrom Type III+

- Interconnect features modified to accommodate input coupler at end of cryostat.
- Quad current leads may be new, with local impact on thermal shields and vacuum vessel ports. May need access ports as well.
- Provisions for quad power lead connection at center of module.
- Some pipe sizes will be increased for lower pressure drops with high flow rates -- would like to retain long cryogenic unit lengths up to limit of 300 mm pipe and cryo plants.  Present effort includes re-analysis of heat loads, flow rates, and cryogenic system thermal process.

- Don Mitchell, FNAL

## Some critical open design issues

**Quad/corrector/BPM package is a major unknown right now and goes into the heart of the module **
- Tuner details, slow and fast, but especially fast tuner** **
- Vibrational analysis, which will be compared to measurements for verification of the model for future design work
- Development of module and module component test plans
- Verification of cavity positional stability with thermal cycles
- Design of test instrumentation for the module
- Robustness for shipping, analysis of shipping restraints and loads, shipping specifications
- Active quad movers(?)  A complication

- Don Mitchell, FNAL

## Probable Design Schedule

- 3.9 GHz Cryomodule Design Completion: 2nd QTR 06
- BCP fixture processing currently underway
- Small design modifications needed to cryomodule components
- Drawings must be checked, approved, and released
- Few resources available at this time
- Americanized CRYO III+
- 3 to 4 months of detail drawings Feb – May ’06
- ~ 3 detailers and 1 engineer
- ILC T4CM
- 12 - 24 months (2006 - 2007)
- 1st international meeting in January 2006, CERN
- Assign responsibilities (FNAL to possibly take lead)
- Engineering issues must be primary focus
- Magnet/BPM package (internal or external to cryomodule)
- Vibration issues
- Tuners, etc.
- Integrate into module design
- Designers will get involved once engineering issues are solved

- Don Mitchell, FNAL