1. 650 MHz Cryomodule -- Discussions at RRCAT October 2010 Tom Peterson, with Harry Carter, Camille Ginsburg, and Jim Kerby 19 Nov 2010

2. Reports about cryomodule work at RRCAT See Prashant Khare’s summary talk: “650 MHz Cryomodule Design at RRCAT”

3. 650 MHz CM work at RRCAT A lot of very nice work has been done Study of existing cryomodules –SNS, Cornell ERL, New Light Source (UK) 3-D CAD model of 650 MHz cryomodule developed in UGNX-4 Building a mechanical model of the cavity support system –Cavity support system modified to include shims between HGR pipe weldment and dressed cavity to compensate for as- delivered pipe not being straight Thermal shield analyses –Eliminate lower half of 5 K thermal shield Vacuum vessel engineering design note Other analyses, piping, etc.

4. 650 MHz CRYOMODULE & ITS SUBSYSTEMS 650 MHz SCRF CAVITY-UNDER FABRICATION AT RRCAT He VESSEL to be fabricatedCAVITY SUPORT SYSTEM UNDER PROTOTYPING AT RRCAT VACUUM VESSEL FOR CRYOMODULE UNDER DESIGNING AT RRCAT THERMAL SHIELD UNDER DESIGNING AT RRCAT CRYOGENIC SUPPORT POST UNDER PROTOTYPING AT RRCAT

5. SCRF Cavity supported on HGR pipe Information required on  Magnet package  Tuner details  Power Coupler B. Glimpses of 3-D Model (contd…)  The model incorporates a modified Cavity support system.  2K helium supply line includes a bellow in vertical configuration

6. Thermal Shield with dressed Cavity  80K- Thermal shield  5K-Thermal shield is partial.(Upper Part only).  Thermal shield 80K shield.  Thermal shield 5K shield is partial. B. Glimpses of 3-D Model (contd…)

7. Reports about work at Fermilab Presentations provided at RRCAT on helium vessel and cryomodule design concepts (from work by Chuck Grimm, Serena Barbanotti, Mike Foley, and Tom Peterson)

8. Information provided to RRCAT Three talks in one large file “650MHzHeliumVessel-Oct2010.ppt” –650 MHz helium vessel design criteria and comments Start to develop a “functional specification” and a “technical specification” Here only a general summary of design considerations –Technical comments from Tom Peterson Copies of slides developed during consideration of various thermal, pressure, and piping issues for 325 MHz and 1.3 GHz cryomodules as well as 650 MHz This provided material for detailed discussions on Friday and Saturday –Background and status details from Chuck Grimm, Serena Barbanotti, Mike Foley Slides from a recent talk assembled by Chuck, Serena, and Mike on the cavity and helium vessel design

9. Discussion of near-term CM tasks The following slides helped to guide our discussion at RRCAT about the work list for the next six months

10. Draft of a near-term task list - 1 650 CM requirements and functional specification (Fermilab) –Continue to collect list of features and requirements –Draft functional specification Refine and update the 650 MHz cryomodule/cryogenic flow schematic (Fermilab) –Illustrate the case of single stand-alone 650 MHz cryomodules –Perhaps include other features like 4.5 K phase separation Consider a BESSY-type scheme with an open-ended cryomodule, cold magnets, but single cryomodule liquid management length, and the option of variable string lengths. –Other ongoing refinements and considerations

11. Draft of a near-term task list - 2 Flow rate analyses and pipe sizing (Fermilab and RRCAT) –Agree on a maximum credible air inlet port size –Review upset condition venting pipe sizing requirements –Review steady-state pipe sizing requirements Continue review of cryomodule operational experience at other labs, especially with respect to CW operation and pressure stability (Fermilab and RRCAT) –Correlate this experience with design features –Visit CW cryomodule labs: Cornell, JLab, BESSY (Berlin) –(I was at Cornell this week. Jlab visit planned 2 - 3 Dec.) –Possible Berlin/DESY visit week of 21 Feb., before TTC in Milan including RRCAT colleagues (Avinash, Prashant, others?)

12. Draft of a near-term task list - 3 Refine pressure change buffering considerations (Fermilab and RRCAT) –Understand (perhaps with a special VTS test) the rate of return to pressure-temperature equilibrium following a vapor pressure change over a 2 K bath –Refine assumptions for heat pulse or pressure pulse drivers –Reconsider liquid and vapor volume advantages Consider warm magnets between beta = 0.9 cryomodules

13. Draft of a near-term task list - 4 Begin a 3-D CAD model of a closed-ended 650 MHz TESLA-type cryomodule (RRCAT) –Cross section like presently conceived at RRCAT and Fermilab (Youri Orlov) –Bayonet connection design detail and heat exchanger size (not details) can be provided by Fermilab –Minimal end length including warm-cold transition. End concepts may be taken from SNS, from Fermilab 325 MHz cryomodule model, from end boxes, and from other sources –New thermal contraction constraints and fixed points –Cavity support scheme and position stability Reconcile results (slot lengths, drift spaces) with beam dynamics people (Fermilab) –Consider warm magnets between beta = 0.9 cryomodules

14. Draft of a near-term task list - 5 Begin a 3-D CAD model of a closed-ended 650 MHz SSR-type cryomodule (Fermilab) –Cross section like presently conceived at Fermilab for SSR (Youri Orlov) –Bayonet connection design detail and heat exchanger size –Minimal end length including warm-cold transition. End concepts may be taken from SNS, from Fermilab 325 MHz cryomodule model, from end boxes, and from other sources –New thermal contraction constraints and fixed points –Cavity support scheme and position stability

15. Meetings every other week 650 MHz joint cavity/cryomodule meetings –Camille, Chuck, Yuriy O., Mike F., others –Avinash, Prashant, Jishnu, others –A details meeting Fermilab and RRCAT already had our first Webex meeting Tuesday morning, 9 Nov. –6:30 AM at Fermilab, 6 PM at RRCAT –Reviewed our work status –Next meeting Tuesday, 23 Nov., same time

16. A concern at RRCAT -- schedule Supplement 1 to Addendum III (to MoU) between Fermilab and Indian DAE Laboratories (BARC, RRCAT, VECC) and IUAC Switch from beta = 0.8, 1.3 GHz to 650 MHz and still evolving requirements makes Q4 2011 design completion unrealistic RRCAT needs the schedule adjusted as necessary when our work forces a slip, such as the lack of specifications due to the evolving concepts of Project X