J. C. Sheppard SLAC September 29, 2006 ILC Positron TDR and R&D Collaboration Meeting 1: Oxford Summary Discussion and Meeting Critique Discussions 9 and 10 J. C. Sheppard SLAC September 29, 2006 1 September 29, 2006

ILC Positron System Design and R&D Goals in Support of the TDR Discussion 9: Z2 Summary ILC Positron System Design and R&D Goals in Support of the TDR Z2: Meeting Summary Discussion: Action Items Z3: Meeting Format Discussion: What Works What Does Not Work What Do We Do Differently 2 September 29, 2006

ILC Positron System Design and R&D Goals in Support of the TDR Discussion 9: Z2 Summary ILC Positron System Design and R&D Goals in Support of the TDR Topic leaders will write a short summary for each meeting with an emphasis on accomplishments and action items: ~One Page The meeting chair is responsible for collecting the topical summaries and writing an overall summary of progress and expected goals by the time of the next meeting. 3 September 29, 2006

Discussion 9: Z2 Summary Topic Action Items: Target Systems Ian Bailey/Tom Piggott Looking to urgently prototype target wheel in UK. No one else currently requesting funding. Test first prototype baseline target at DL in Summer 2007. LLNL, Liverpool, DL to present p’type drawings at Feb ’07 meeting. Estimate force on wheel from pulsed OMD. Jeff to coordinate. Specify how prototyping plans depend on outcome of OMD studies. RAL/DL report on impact of remote-handling strategies (see target hall session) on target design at Feb ’07 meeting. Number of R&D cycles, milestones and timeline will be agreed by main participants by Dec ’06. John S to coordinate. RAL/Liverpool to investigate materials for the target rim and provide material spec sheets for Feb ’07 meeting. Ian will coordinate. Viability of beam windows (eg between target and accelerating cavity) needs to be definitively investigated. Plan needs to be in place by Dec’06. Vinod will coordinate. Viability of liquid metal target depends on proven design of suitable beam window . Cornell may wish to report on this issue at the Feb ’07 meeting. 4 September 29, 2006

For pulsed OMD need development plan Discussion 9: Z2 Summary Topic Action Items: OMD Jeff Gronberg Need to answer question of immersion effects in order to make OMD choice: need simulation benchmarked with experiment For SC solenoid need to understand radiation, power depo conditions and rad damage (simulation) For pulsed OMD need development plan Investigate range of zero field on target OMDs (MK at KEK) Report results and plans of spinning wheel experiments at Feb meeting 5 September 29, 2006

Discussion 9: Z2 Summary Topic Action Items: Capture RF Juwen Wang Progress. Five-cell L-Band SW test structure for capture section is under fabrication. Almost all parts and subassemblies are either done or in process. Still a lot of work need to be done in order to complete the final assembly by the end of 2006 or the beginning of 2007. All of five sets of parts for L-Band RF windows are in hands. A completed window is under cold test. Five vacuum flanges for test structures and Couplers have been completed. 2. In order to have a solid design for both positron and electron sources, we should fund a R&D program for L-Band TW structures. There are many challenges in both electrical, mechanical designs as well as fabrication aspects: They are long, the balanced cooling and pumping systems needs to be carefully studied and inductive brazing technique needs to be practiced at SLAC. They have low group velocity (as low as 0.16%c), the impact of big transient effects needs to be investigated and tested. They work at long beam pulses (1 ms), the operational stabilization needs to be studied and tested. 6 September 29, 2006

Target Hall Vinod Bharadwaj Discussion 9: Z2 Summary Topic Action Items: Target Hall Vinod Bharadwaj More activation/damage calculations Identify what numbers are needed from the calculations Figure how to do the simulation – which program(s) etc. identify people to do the simulations include detailed layout of hardware: OMD, SW RF, TW RF, solenoids, shielding Define target hall dimension requirements target hall occupancy needs needed shielding what is in the hall and what is on the surface scenarios for all the needed repair/replacement operations KAS target hall Does ILC plan to have a central hot cell facility? e+ , dumps etc. will it be useful for the positron stuff Re-visit two/one target requirement (availability, R&R time,……) 7 September 29, 2006

Undulator Scheme Jim Clarke Discussion 9: Z2 Summary Topic Action Items: Undulator Scheme Jim Clarke Two sets of conflicting undulator parameters are proposed – ‘high K’ and ‘low K’. This should be resolved as a priority. Start to end simulations carried out with a benchmarked code are needed from the entrance of the undulator to after the positron capture section to understand the differences. Results to be reviewed at the next meeting. In the meantime the UK undulator parameters are adopted as the baseline. Period = 11.5mm, beam aperture = 5.85mm, Kx = Ky = 0.92. UK to prototype 4 m module in calendar 2007. Beam test plan should be reviewed at the next meeting. Need magnetic measurements plan for the long prototypes UK group to review 80% design margin by Feb 07. 8 September 29, 2006

F. Laser-Compton Scheme Masao Kuriki Discussion 9: Z2 Summary Topic Action Items: F. Laser-Compton Scheme Masao Kuriki Develop full design which is compatible with current ILC design: full source accelerator design: OMD, rf, yield calcs Simulation of compton ring dynamics, incl nonlinear beam dynamics Simulation of e+ stacking in the ILC DR. Optical cavity and laser experiments „Schedule“ for compton scheme development, now thru completion: how to we get from here to there 9 September 29, 2006

Conventional Scheme Bharadwaj/Sheppard nothing to report Discussion 9: Z2 Summary Topic Action Items: Conventional Scheme Bharadwaj/Sheppard nothing to report 10 September 29, 2006

Accelerator Physics Gudi Moortgat-Pick Discussion 9: Z2 Summary Topic Action Items: Accelerator Physics Gudi Moortgat-Pick Collect into a single report dilution and depolarization studies; what additional issues? Propose how to do commissioning w/o Keep Alive Source Start-to-end tracking w/ spin tracking, schedule Fix GigaZ parameters Optical Deck for specifications and tolerances Status of e+ tracking studies incl/ e- thru undulator insertion (ILC low emit folks,….) 11 September 29, 2006

Polarization Sabine Riemann Discussion 9: Z2 Summary Topic Action Items: Polarization Sabine Riemann Report on tools and scope of activities at Feb. meeting 12 September 29, 2006

ILC Positron TDR and R&D Collaboration Meeting 1: Oxford Discussion 9: Z2 Summary ILC Positron TDR and R&D Collaboration Meeting 1: Oxford Thanks for coming to this meeting and a special thanks to Yury Ivanyushenkov and Glyn Northing for organizing us and to RAL for hosting us Next Meeting: Asia, M. Kuriki prior to and in association with February GDE Beijing Meeting 13 September 29, 2006

ILC Positron System Design and R&D Goals in Support of the TDR Discussion 10: Z2 Summary ILC Positron System Design and R&D Goals in Support of the TDR Discussion: Every thing is open for discussion: format, discussion leaders, topics, organization, schedule, ILC Will have a session on Friday to discuss how this meeting has gone; what changes are required; what went well; what is clearly not working;……. I think that it will take about 3 meetings (1 year ) to settle out on this process (allow phone and video links to the 3 annual meetings Gudi Mortgat-Pick makes and maintains group mail server Declare a spokesman for collaboration: J Sheppard, for the time being 14 September 29, 2006

Discussion, comments, suggestions Discussion 10: Z2 Summary ILC Positron System Design and R&D Goals in Support of the TDR Discussion, comments, suggestions What Works What Does Not Work What Do We Do Differently 15 September 29, 2006