Minutes of the DRAGON group meeting November 6, 2007



Present: CD, LB, PM, PB, UH, CV, GR, MA, AO, DH (recorder)



1. Minutes of previous meeting: business arising

	- Yale source: no one at this meeting had authoritative update

	  from last week.

2. Hardware

	- Turbo TP32 kept tripping off.  At first it was believed to be

	  related to the EPICS Auto-backing feature, but problem turned

	  out to be failure of a fan on the turbo controller box.  The

	  fan has been replaced.  PM/UH asked about the "BP off

	  for 15 minutes" feature in Auto mode.  DH did not recollect

	  why/how this feature was introduced.

	- End station upgrade (CV): there have been more discussions

	  and measurements involving Dan R. of the Design Office.  He

	  has produced a concept drawing of the Final slit box, showing

	  relocated slits, MCP, a second MCP and the Faraday cup ("no

	  collision with MCP will be possible").  The

	  MCP foil holder will be mounted on the mirror frame.  Existing

	  drawings were incorrect in many instances.  It is expected that

	  the detailed drawings can be done by the end of 2007 and that

	  the new top plate and side plate will take ~1 week in the 

	  Machine Shop.  (Moving the Box downstream will be a bigger 

	  deal--conduit, grout,...)



3. Solar cells  (UH)

	- A pulser signal was sent in the absence of alphas: not all

	  channels responded equally.  The alpha rate was a few per

	  minute, rather than the expected 15-20 per second.  One issue

	  may be the bias resistor which is putting a high offset (in

	  some cases close to the max. of 1024 counts) on the waveform

	  digitizers.  (They are optimized for TACTIC.)  GR will see

	  about getting resistors changed.  There are 3 cell which are

	  excessively noisy or have no signal.



4. EEC proposals and priorities

	- there was no disagreement with the CR's list of beams ordered

	  by feasibility: Na-22, S-33, Mg-23, Ne-19, F-18, F-17, Al-25,

	  C-11, Al-26m, N-13, P-30, O-15.  To be inserted yet: Mg-25,

	  C-14.  The DRAGON presentation should present the physics

	  priorities disregarding availability, then the feasibility-

	  ordered lists for radioactive beams and stable beams.

	- except for N-13, the one-page updates or the new proposals

	  have been circulated; CR is working on N-13.  Meaning of

	  "percent of research time devoted to experiment" is unclear.

	  Spokespersons will have to sort this out with collaborators

	  before submission deadline on Friday.