Minutes from DRAGON meeting December 20, 2005
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Present: D.Ottewell, L.Fogarty, C.Ruiz, D.Hutcheon(recorder), J.Pearson, 
C.Vockenhuber, P.Machule

1. Report on Si charge state distribution run  (CR)
	Extraction of 28Si(1+) was not feasible due to N2 background.  
Instead, OLIS and RFQ ran on 28SiH3(1+), the DTL on 28Si(5+).  There was a 
A=31 was at the limit of OLIS HV range and above RFQ rf conditioning.  
There was a worry about 17O(3+) contamination, but this was shown not to 
be a problem by running attenuated beam into the ion chamber and looking 
at E-dE.  
	Measurements of FC1 or FCCH currents vs HEBT:FC4 were done for 
no-gas or cell pressures of 1, 1.5, 2, or 3 Torr.  Method was to record 
FC1 on stripchart for 7 minutes, then FCCH for 7 minutes with brief 
interruptions to check beam at FC4.  The FC1/FC4 ratio might not quite 
have reached equilibrium at 3 Torr; severe OLIS sparking at 63kV developed 
before a measurement could be done at 4 Torr.

1.5  Energy resolution of Ion Chamber vs DSSSD  (CV)
	The attenuated 28Si 180 keV/u beam was used to measure energy 
resolution of  the IC, for comparison with DSSSD data with attenuated 26Al 
201 keV/u beam,  The IC resolution was 4.4% FWHM vs DSSSD resonution of 
9%.  In addition, the IC spectrum had much reduced low-energy tail (see 
attached figure).  In this test, the IC entrance window was SiN; at least 
part of the difference in FWHM should be ascribed to greater energy 
straggling in the dead layer of the DSSSD.

2.  Six Months with DRAGON   (LF)
	Lisa Fogarty (National University of Ireland, Maynooth) summarized 
the results of various projects worked on during her 6 months with the 
DRAGON group:
	* beam normalisation for the 26Al(p,gamma) experiment (E989)
	* efficiency calibration of the "positron horn" and Ge detector
	  used to measure beam contaminants in E989
	* study of backgrounds in a Ge detector for the 22Na(p,gamma)
	  experiment (E1027) and their suppression by anti-coincidence
	  counters (NaI or plastic scintillator)
	* assembly and vacuum testing of a chamber + valve assembly for
	  use by E1027 at the University of Washington
Lisa presented the group with a copy of "The Hobbit" to be added to the 
DRAGON library.

3. Hardware
	* the BGO HV unit was replaced but there are problems talking to
	  the replacement via camac.   (JP)
	* there will be a power outage between Xmas and New Years which
	  will affect ISAC-1 hall.  DRAGON devices will be powered down
	  before the end of this week.  (DH/DO)