Minutes of September 10, 2002 DRAGON Weekly Meeting

Present: Joel Rogers (JR), Dave Hutcheon (DAH), John D'Auria (JDA), Dave
Ottewell (DO), Allison Laird (AL), Art Olin (AO), Mohan Chatterjee (MC),
Lothar Buchmann (LB), Peter Machule (PM), Cybele Jewett (CJ), Dario
Gigliotti (DG) recorder.

1) Corrections to Previous Minutes
(to be supplied later)
2) Facility
-DO reports a leak in the gas target box
-an attempt will be made to reseal and pump the box down again
-JR did some work on the elastic monitors and he reports that noise
appeared as low energy tail on the peak which contained ~25% of the peak
counts
-one of the two elastic monitors is currently unavailable (has not been 
used regularily)
-gap left by the cable has been covered with tape to prevent leakage from 
inner gas cell to outer
-after replacement of the cable and re-soldering of some connections the 
noise in the alpha peak has disappeared
-it was suggested that some re-engineering of the gas cell be done to
help with ease of assembly and disassembly
-AO suggested conditioning of dipoles in upcoming run
-DAH reports all necessary DRAGON equipment is functioning properly for
running conditions
-there was a suggestion by DAH to modify the procedure for providing 
locking NMR's over a wide range using EPICS
-is there interest in persuing this possibility?
3) DSSSD report by JDA on behalf of Chris Wrede (See Attachment for
further details)
-a new design for the cooling system uses a copper tube to shield the
detector from radiation
-an improvement in cooling of about 12 degrees was observed with the new
system
-initial measurements show a small increase in resolution but further
testing is required and will be carried out to be assured of this point
-in light of these initial results there were some questions from members 
of the group whether to
pursue the cooling tests further
-it was noted that cooling will affect resolution of heavy ions less than
alphas
***Post Meeting Chris Asked to have the following added to the minutes
-it should be noted that the INITIAL resolution data was taken with an old
detector and caution should be taken when viewing these first results
-to be sure of the effects of cooling a good/new working detector needs to
be tested
-energy resolution being the same a cooled detector is still better than one
which is not
4) MC Presented a report with Suggestions and Possible work/Test Plan for
the PGAC
-for details of the presentation see the attached slides
-it was noted by JDA that plan and development for the PGAC will be
returned to
5) Upcoming Run
-check circulated email of Mg24 Run Plan from Sept 9 by
DAH for details of upcoming run
-scaling for the elastic monitors and DSSSD has been changed so that 100
channels = 1 MeV
-elastic monitors now see an alpha source placed in
the box
-it was requested that the amplifier gain NOT BE CHANGED for the
elastic monitors
-threshold may and can be changed if required
-monitors are operating normally
-for the upcoming and future runs be sure to fill out BOTH the BEAM
PROPERTIES sheet and RUN SHEET for each energy change or run as required

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