Meeting minutes Tuesday 13th May 2003

Present: AB (scribe), CG, CJ, CR, CW, DG, DH, JDA, JR, LB, MA, ML, PM, SE, ZL

First we would like to welcome Cassi Galt to our group for the summer from the 
University of Toronto.

1. Corrections to last week's minutes: None.

2. Faculty mini status report.
	Progress has been made on purchasing a chiller. The used damaged 
	detectors will be used for test runs.
	DH: a) The side plate is out of the shop. b) A short out has occurred
	in the MCP between the positive and negative power supply by one of 
	the mirror wires. c) Backing pump BP31 should automatically come on 
	when CG31A reaches 0.4 Torr, which it did not. The EPICS backing pump 
	control was not working and it was not clear how to get it started 
	properly. d) The solid graphite target system is currently being 
	assembled.
	JR: Software malfunction over the weekend. Error messages were found 
	in MIDAS.LOG (see attachment 1). These messages appear on the 
	downstairs computer, but on the computer upstairs in the counting room,
	only the last message is given. ZL noticed the analyzer, which takes 
	the data to the logger, was missing from the list around midnight on 
	Monday. JR has clean up the 10'000 or so error messages. Early on, a 
	reboot would have cleared the messages. We lost the last hbook file 
	from the last 12C run. Discussion of maybe installing a voice message 
	alarm to isdaq04.

3. Status/plans for 12C(a,g)   LB
	Scaling program troubles reported by LB.
	FCCH/FC4 ratio graph ? too much scatter (around 30%).
	Recoil counts ratios between singles and coincidences are not 
	consistent. Except for strong resonances, the apparent BGO 
	efficiencies are too low.
	Normalized yields for the ground state and for cascade transition as a 
	function of beam energy.
	Normal resonances were observed, but peak-to-valley ratios sometimes 
	did not match literature values.
	JR is going to closely analyze the four lowest energies of LB data.

4. AOB
	Currently the ECR is not working yet. It is uncertain when we'll get 
	radioactive beam. We need to understand these 12C bugs before the next 
	beam, before the EEC deadline.

	DH: (see attachment 2) The widths and centroids of the coincidence and 
	singles peak are different. The ratio of counts gives an apparent low 
	BGO efficiency. Is something getting lost in the coincidence spectra, 
	or could it be oxygen knocked off the metal walls of the gas target? 
	Some background appears around 12C(4+). There are questions over what 
	the other stuff may be.

	Germanium detectors to resolve the transitions between 6 and 7 MeV, 
	was discussed. JDA suggested borrowing one from 8pi.

	DG: Continuation from last week's report. DG has now looked at the 
	effect of simulating varying the diameter of the NaI crystal in GEANT 
	(see attachment 3 page 1) for comparison with the measurement that was 
	done earlier. Four lots of data was taken with a Al casing of 0.6mm, 
	and another two lots of data was taken with an Al casing of 2mm. All 
	data was taken with the same simulated crystal (which separates the 
	crystal from the PMT), except for the last lot of data with the 2mm Al 
	casing which using a second simulated crystal which is connected 
	straight to the PMT and the Al casing covers the entire detector (see 
	attachment 3 page 2). This second simulated crystal better modeled the 
	geometry of the actual crystal.