SLAC ILC R&D Progress Report-10/10/2005 (33)

1:30:30 PM-2:30:30 PM

 
Agenda: 1.) Mauro Pivi - Electron Cloud R&D
2.) Marc Ross - ATF Studies:
- Kicker studies - ATF ring BPMs
Summary: See talk summaries

1 .) id=97  Mauro Pivi --  Status of SEY & Electron Cloud R&D  (20 min)

Summary: The first grooved beam pipe is under contruction.

2 .) id=98  Marc Ross --  Status of R&D at the ATF  (30 min)

Summary: 1) Kicker RD.
In preparation for the Snowmass meeting 3 very fast kicker pulsers (<3ns rise time, 5KV) were tested at ATF in May 2005. The three came from LLNL/SLAC, DESY and KEK (FID company) and all 3 basically met the specification. At Snowmass, the kicker RD group stated that the kicker results were sufficient to allow for rings with 6 ns bunch spacing or larger. Further RD, to be done in 2005, included 1) droop correction, 2) pre-post kicker studies, 3) pulser 'lifetime' studies and 4) rise time reduction work. Last week, the KEK ATF group proposed a ring extraction scheme that requires only 1.5 m of kicker magnets, operating at about +/- 12KV. One of the easiest ways todo this is to use a very long stripline system with the LLNL pulser set to wide pulse operation. This would cost about 20K$ and would allow the generation of about 6 bunches with 300 ns spacing in the extraction line, a 'mini' ILC train. A more realistic scheme, with four shorter stripline magnets and pulsers matching their length would cost about 250K. The KEK group has this underconsideration and will be working with SLAC/LLNL to develop a realistic strategy.

2) ATF ring BPM RD.
Based on ring coupling, dispersion and emittance measurements, we think that the previous BPM improvement directly affected the ring performance, resulting in record low numbers ~ 4 pm-rad. By reducing the BPM resolution further, and correcting offsets and roll, both of which are known to be electronic in origin, we think we can reduce the emittance below 1pm-rad. This would allow more direct scrutiny of the ring operation and perhaps better understanding of mid-term (days) stability issues. To do this, given the FY05/06 budget alloted to the task, we will borrow 10(?) Echotek modules from SPEAR and prepare a front end down-mix receiver / calibration scheme for testing in February. At that time we will (Andy, Janice, Mark, SPEAR and me) go to ATF and test the BPM's and improved tuning process. We expect ~2um single pass resolution from the new BPM system, constant (live) averaging, constant (live) calibration using a fixed 'offset' tone and improved offsets. The SPEAR equipment will be returned after the experiment and, if successful, we will submit a proposal to KEK for funds to support the full system.