NOTE: Place Change. Meetings are held every THURSDAY, 1:00 PM IN (BLDG. 58), TEST LAB CONF ROOM, unless otherwise notified.

ATTENDEES: S. Benson, G. Biallas, J. Bisognano, C. Bohn, J.C. Denard, D. Douglas (3/7 only), L. Harwood, K. Jordan, D. Kashy, D. Kehne, G. Krafft, R. Legg (3/14 only), C. Murray, G. Neil, J. Parkinson, M. Wiseman, B. Yunn.

Decisions/Comments:

D. Douglas reports that the design of the wiggler-downstream option continues to converge. The design uses 13 more quads for the drift regions He continued to recommend going ahead with roughing in the designs of end magnets, and the quads and ordering the material for the end magnets on that basis.

The last two quads in the injector region seem to be too close to each other to avoid cross talk. The dipoles will be very narrow when including their effective length. We need to address these issues.

The two optical chicanes could be considered a string of magnets on one supply. Both arcs can be on the same string.

There may be an operational need to have a bypass around the wiggler. D. Douglas is studying it at a lower priority level

The preliminary judgment of those at the meeting of 3/14 was that the phase adjustment to be built into the end dipoles was +-20°. This could be achieved by a combination of occasional movements of the dipoles by surveyors using the adjustment cartridges on the stands and modification of the orbit by several mm using adjustments in the end dipole strings. This still needs to be checked with D. Douglas.

G. Biallas announced that to meet the budget goals for the project; he had to simplify the design of the vacuum system, removing valves, bellows and flanges. The machine will have to be welded in situ in some instances. The magnets also required simplification. He will no longer put in coils that can be used at 100 MeV. If any of these tasks becomes more complex than he envisions, we will have to have a change request and get money out of contingency.

Action Items:

G. Biallas/J. Parkinson - Do the appropriate calculations and get Sign-off on relaxed vacuum requirements near cryomodule by R. Sundelin & P. Kneisel. We need the hard interlock values for closing valves. No progress.

D. Douglas - Add the bunch lengths to zones on the layout drawing so impedance issues can be assessed. No progress.

C. Murray - Add a 6 inch wide tube to the chamber intersections at the injection crotch, dump crotch and laser mirror ports. Half complete

J. Bisognano/B. Yunn - Make a list of impedance issues and begin analyses. Known issues discussed to date include impedances of the crotch chambers associated with the wiggler, and vacuum-pipe transitions. Some progress. B. Yunn appealed for references on the Cookie Cutter design because the ABC code doesn't

C. Bohn - Address injector issues in the comments.

K. Jordan - Resolve the question of whether we need a 5th OTR in the Wiggler region.

J. C Denard - Calculate from the Hall C data how much scatter the BPMs can take. Scheduled for after the review.

C. Murray - Put parallel faces on the optical chicane dipoles.

Completed Action Items:

C. Murray/D. Douglas - Shift the injector upstream to the correct origin, shorten the magnets to 2/5 length and make the magnets wedge style. Complete.

C. Murray - Add cookie cutter beam tube transitions to all positions that have a tube going from large to small. Complete.

J. Parkinson - Find out how effective the electrostatic precipitator at the front end of the first linac was. Unable to be assessed, the precipitator was washed without analysis. As a future action item, we should assess a precipitator at the next shut down. Complete.

S. Benson/R. Boies - Layout the proposed Optical Cavity. Complete.