Minutes of the DRAGON meeting November 12, 2002.

Those present: JR, SE, JDA, DO, DH, AO, LB, AL DG, CJ, SB (late)

By: LB

Minutes: After minor corrections accepted.

Business arising:

Number of DSSSD detectors: One alive, built in, 1 or 2 to be ordered.

Computer controlled NMR: The expert showed up, but it appears that at the
            moment we are still on run and knob mode.

Digital camera: works with nice photographs of the beam. Implantation into the
                network is in progress.

Elastic monitor: The problem with the insulated feed-through for
 the detectors has been fixed.

Actual News: In the yield measurements 2x10^8 s^-1 ^20Na were observed
with the new SiC target and 45 uA of proton  current.
              The energy calibration with ^20Ne beam 
at DRAGON showed differences of 0-3 keV/u between Prague magnet and MD1. The
Prague magnet calibration looks therefore alright or as good as it gets. 

Adventures in Belgium: SE reported about her visit to LLN: The recoil separator
ARES is under test. The ^19F(p,gamma)^20Ne reaction has been used. The
angular acceptance of the separator is 12 mrad, leading to considerable 
losses. The beam suppression without detection seems of the order of 10^-6.
A DE-E ionization chamber-Si detector separates the leaky beam from the
reaction products. A 19Ne(p,gamma)20Na run is just taking place now.

The design of the LLN LiF targets for 15N production was presented;
i.e. a graphite matrix with voids charged with LiF. A similar
^15O beam production at the CP 42 was discussed.

Upcoming 12C run: After the TUDA run, DRAGON will receive a 12C beam.
It will be tried as 2^+ beam from Olis, i.e. without stripper.
That may require some tuning time. It is proposed to start at the
1.08 MeV/u 4^+ resonance and move upward from there.
It was discussed to use two elastic monitors, as the alpha recoils
should be visible in the 55deg detectors. The question of the implementation
of BGO-RF coincidences was also discussed.

^21Na(p,gamma)22Mg data analysis and article: SB gave a summary
of the cuts applied, the short of it is that JR gets the same number
of valid counts in the analysis. However, we would like to have
a table compiled with all the input numbers for the final omega-gamma.
This includes errors in the charge state distribution, gamma efficiencies,
transmission, Si-efficiency, energy loss. Fig. 3 of the draft PRL article
was discussed. JR provided an alternate figure with four panels showing
2D TOF-EG, EG gated, TOF, and HI gated. A discussion about the validity
of the April data arose in which runs no elastic TOF was available.
The question of beam normalization via the beta monitor should be investigated.
In the long run, the shape of the gamma spectrum should be understood to,
in principle, conclude on branching ratios and angular distributions.

Upcoming ^21Na run: The program for the upcoming ^21Na run was discussed.
It was agreed to do the two resonances around 500 keV/u again, and 
look for other things, if time permits.