Present: Chris Allgower, Andy Bacher, Paul Pancella, Tom Rinckel, Sitaram Shastry, Ed Stephenson
Meeting came to order at 3:10 pm.
FABRICATION TASKS, WIRE CHAMBERS
Tom brought drawings of the septum magnet and surrounding area for consideration. The magnet and its vacuum chamber are built, and work is starting on the magnetic shielding for the Cooler beam pipe. The geometry is still very tight, but it appears to be possible to mount this shielding along with everything else. Idea is still to map the field inside the shielding at the correct position of the Cooler beam relative to the septum magnet. Alignment requirements and challenges were discussed in view of the required precision.
Wire chamber construction is coming along. Circuit boards are back and shop is machining some O-ring grooves. It is still possible these will be ready in time for the channel test run.
Pumping of the channel vacuum was discussed. One or two mechanical pumps (two separate volumes could be joined by tubing) will be used, as channel vacuum is always isolated from the Cooler high vacuum. Oil traps will be employed to keep the windows clean.
It was decided that the first vacuum window (exit of 6 degree magnet chamber) should be 5 mil thick Kapton, and the next three can be 3 mil thick, as they are all of modest size. The final exit window at the end of the channel is another story, as it will be considerably larger. The availability of Kapton film thicker than 5 mil is in question. Walt Fox has done a calculation indicating that 8 mil might be sufficient, but safety factor is only about 1.7. This requires further study before a final design is made for the large exit window.
SCINTILLATORS
All materials are in house for the first generation of scintillation detectors, including new PMTs, and drawings are complete. The first deltaE detector will be read by one phototube, as will the two veto detectors. The other two detectors will be read by phototubes on both sides. It appears that machining of the light guides has begun in our shop, so these detectors should also be ready in plenty of time for the test run.
ELECTRONICS, OTHER REQUIRED EQUIPMENT
The request to Brookhaven for something more than 66 modules has been approved to the level of the Physics Division there. Probably time to start thinking about delivery. A request for remaining modules has been submitted to LANL, but due to the sorry state of the pool there, we should not expect immediate action. The head of the electronics pool at Fermilab is sympathetic to our needs, but there the bureaucracy is a challenge. Ed also discussed the matter with MSU. There the problem is a 6-month scheduling cycle, meaning that only short-term loans without much advance notice are possible. We still need to look carefully at our FERA options.
In the meantime, Chris has obtained a large number of scintillation counters from Argonne which he can use for spare phototubes.
Don't forget about the visiting committee December 18-19. We may be asked to prepare more than one poster in addition to Ed's talk.
The meeting adjourned at about 4:40 pm.