Present: Chris Allgower, Andy Bacher, Jack Doskow, Anders Gardestig, Hermann Nann, Paul Pancella, Tom Rinckel, Ed Stephenson
The meeting came to order in the south large conference room at 10:10 am.
Tom Rinckel presented some Gantt pages for the rest of the CE78 installation. It should be possible to have all components ready to install by August 1 of this year, even considering various vacations. We still need to do some thinking about magnetic shielding for individual lead glass phototubes. We must also try to figure out how to make the downstream detectors larger, in view of the fact that John V. is very busy now. It should not be necessary to enlarge the downstream beam pipe. No other major jobs seem to be missing from the plan, and the target box seems to still be on schedule.
Design of supports for the lead glass stacks has begun. Jack Doskow presented drawings of the early concept, concentrating on the more difficult side, beam right. The group came to agree that it might be worthwhile to eliminate one of the plate shelves and place the lower cosmic ray paddle on the plate that supports a pair of Thompson rails, between the rails. This probably excludes the use of an existing scintillator, but a new one will not be very complex or difficult to build. On beam left the Roots blower will have to move, and perhaps some shielding blocks as well. Tom doesn't see this as a problem.
Pancella presented some early analysis of the channel test run. First was a measurement of the Cooler closed orbit circumference based on the online width of the 3He cone at WC1. Good agreement is seen among about a dozen measurements and with previous results, although the preferred value may be a centimeter larger than the 86.77 m previously published. Second, he showed that the pattern in WC1 cleans up nicely when the sample is restricted to events with multiplicity=1 in all 3 planes (xyu) of that detector. The apparent- ly "hot" y-wire disappears, and the shapes are as expected. A break- down of the different multiplicities shows some random noise, some inefficiency, and some real 2-prong events in the sample. The multiplicity pattern depends on which particles are observed. Preliminary analysis of the shape of the projections indicates that with a cone of 1.45 degrees we lost only about 5% of the 3He particles due to the vertical size of the downstream scintillators. A more detailed report on the Cooler circumference measurement is available on request.
Stephenson then presented the latest outlook on the future Cooler running schedule. Relevant to this project is the likelihood that Nuclear Physics operations will cease at the end of September, 2002. CE78/82 is slated to receive much of the remaining Cooler beam time, but that still leaves very little margin for error if we are to get the desired statistics. It also means the cancellation of PINTEX small angle running, so we have to rethink our calibration procedures. Lab policy for the rest of this time is that Cooler and cyclotrons will always run simultaneously.
Both machines will be shut down for the first 3 weeks of July, at which time our channel will be pulled out of the way and the Tagger system restored to working order. Sometime in August and September of this year, the Tagger experiment will have its final shot, either with the new liquid hydrogen target or a scintillator target. October and November are then scheduled for the final installation of our CSB experiment, with its new target box and lead glass array. Polarized deuteron beam development and a proton calibration run could take place late in 2000 or early 2001, followed as soon as possible by production running with deuteron beam. The beam is scheduled to be off for three months in the summer of 2002.
After some discussion, the meeting adjourned at about 11:45 am.