1. 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

2. 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

3. 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

4. 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

5. 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

6. 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

7. 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

8. 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 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

9. 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

10. 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

11. 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

12. 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

13. 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

14. 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

15. 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