Agenda

1) Progress on HA power supplies for ATF2 -- Paul Bellomo
2) Update on magnets for ATF2 -- Cherrill Spencer
3) Update on IR shielding -- Alberto Fasso
4) Updates on losses in 2 & 20/14mr extraction -- Sasha Drozhdin, Yuri Nosochkov
5) Missing bend strategy and upgrade to gg and back

Summary

Tests of High Availability power supplies is ongoing at SLAC aiming to deliver prototype at the end of March. Criteria for evaluation of the prototype were suggested. A work-around during decision period was suggested which can mitigate schedule issues if decision on the types of power supplies for ATF2 will be delayed even as far as end of July.

Cherrill discussed progress with ATF2 quads at IHEP after the trip last week, in particular the issue of schedule (not all quads can be ready by the end of march) and jumps in measured strength, attributed at the moment to rotating coil measuring system (not confirmed yet).

Alberto presented IR shielding for non-self-shielding detector, with concrete wall. The wall is 10m away from the point where 18MW beam can be lost. The minimal thickness of the wall is about 3m, to reach the 25rem/hr limit.

Yuri Nosochkov summarized results from Sasha Drozhdin et al, for detailed studies of losses in 14mrad and 2mrad extraction lines. For 14mrad, the results are very similar to Yuri's earlier calculations. New information in Sasha's studies is SR from disrupted beam, which in some cases give noticeable contribution to total losses, up to as much as 0.76MW for 2mrad 1TeV CM case.

Item 5) of agenda could not be discussed due to lack of time.

Andrei Seryi, 03/01/06