Minutes of DRAGON meeting October 1, 2002

Present: D.Hutcheon (recorder), D.Ottewell, L.Buchmann, P.Machule,
C.Jewett, D.Gigliotti

1. Minutes and business arising
	- attachment of DH's comments on O-15 prospects was omitted.
	Will attach it to this week's minutes.
	- the Xantrex power supplies for SX3/SX4/Q9/Q10 have arrived.
	The Philtek supplies for MD1/MD2 are still being tested at the
	factory.
	- the elevated walkway is complete, except for one step.
	- M. LeRoss claims to be too busy on high prio. jobs to look
	at the ED ion pump readout needs.  No progress.
	- Leybold dry pump has been shipped off.

2. Announcements
	- housekeeping (DH)
	A small splitter box was left on top of MD1.  It had a 40-cm BNC
	coax cable dangling over the edge of the magnet and wedged into
	the high-current DC lead of the upper coil.  The outer insulation
	was melted on the bottom 3 cm of the coax.  This is potentially
	very dangerous for personnel.  Metal objects must not be left
	loose on the tops of magnets.

3. Plans for stable beam running Oct 3-8
	- priorities proposed in DH note circulated with the agenda were
	adopted: 21Ne(p,g) scans of the 501 and 733 keV resonances, to
	check out energy calibrations and yields.
	- hardware status: no known problems.  An LED has been put into
	the gas cell to provide light-on-demand for camera focussing.
	Target has been pumped down and appears leak-tight.
	- soccer and other conflicts in the shift schedule circulated by
	JDA will be worked out by those involved.  The proposed "shift in
	shifts" to 06-14, 14-22, 22-06 was not implemented because of lack
	of time to get full feedback on implications; we should plan to
	use it in the 21Na runs if no killer objection is raised.

4. Analysis results
	- ion chamber response  (CJ)  see attachment for plots
	The ~500 keV/u 21Ne(p,g) ion chamber results have been compared to
	to expectations based on SRIM.  The observed 21Ne or 22Na energy
	loss in anode 1 vs anodes 2-5 is low compared to the trend
	expected from SRIM.  
	For anodes 2-5 there is much better agreement between data and
	calculated energy losses if the entrance window is taken to be
	about 4x thicker than its nominal 55 ug/cm^2.  Measurement of
	the thickness of another foil from the same batch using E-loss
	of alpha particles should be sensitive enough to tell whether
	the window is the nominal 55 ug/cm^2 or 4x that value.

	- estimates of beam energy steps  (DH) [note of 24 Sept 02]
	For the recent scan on the 214 keV resonance in 24Mg(p,g)25Al we
	have measured energy changes by: Prague magnet, MD1, Elastic
	Monitor pulse height, and Elastic Monitor r.f. timing.
	The Prague magnet and MD1 agreed to 8 parts in 10000 on the
	energy scale, with variation 0.23% (sigma).  The Elastic Monitor
	pulse heights had 2% (sigma) variation compared to MD1.
	The r.f. time vs magnet was generally consistent, except for
	run 6857 which was 12 ns different from runs which followed with
	no requested change in beam energy.  
	Excluding run 6857, r.f. timing vs MD1 was consistent to 0.13%
	(sigma) and vs Prague magnet to 0.2%.

5. AOB
	-none