Minutes of DRAGON Meeting held December 10, 2002

Present: L.Buchmann, J.D'Auria, S.Engel, D.Gigliotti, D.Hutcheon,D.Jenkins,
A.Laird, P.Machule, A.Olin, D.Ottewell, J.Rogers (recorder), C.Wrede,
S.Bishop(late)

1. Minutes of last meeting were accepted without comment.

2. Post mortem of just-ended beam run - The run was successful except for
a few computer glitches. A feature of the yellow pages on isdaq04 is that
if isdaq04 does not boot (as it did not due to a disk mount problem),
isdaq03 can't be used by dragon either, though tuda still works since it's
yellow pages are on isdaq03.

3. PRL paper on Shawn's thesis data - A.Olin asked for a discussion of
errors, especially charge-state fraction, gamma efficiency, and dE/dx.
J.Rogers claimed that the beam normalization errors also need discussing.

4. Gamma array efficiency - D.Gigliotti showed a comparison of his GEANT
simulation for a 3-inch NaI cylinder with published simulations by Marion
and Young. The agreement was within 5% across the energy range from 0.5
to 10 MeV, which gives us some confidence that our simulations are OK. Art

Olin said he wanted to see data to back up the BGO simulations. J.Rogers
countered that the GEANT simulation should be good enough for the PRL
paper.
S.Engel suggested using 3.5 MeV gamma rays from stable beam data for
which the H-singles to Coincidence ratio gives the overall gamma array
efficiency.

5. 12C(a,g)16O data analysis - J.Rogers presented data analysis of the
recent data at 1066 keV/u resonance, which decays by 2-gamma cascade. The
Midas Analyzer was modified to bin the data by gamma angle, which showed
that the first-gamma (4.5 MeV) has approximately the expected shape (see
attachment), as presented yesterday by L.Buchmann to the EEC. The angular
distribution depends critically on the gamma detector efficiency as a
function of angle, as opposed to the earlier yields which depend only
on the efficiency as a function of z-position.

6. Requests for stable beam running - Starting in February 2003, stable
beam will be available. The DRAGON users are requested to forward
individual requests to J.D'Auria for finalization the first week of 2003.
RIB will not be available until March, and the ECR source not for some
months after that.

7. Awakening the DRAGON - Sabine Engel rehearsed her talk to be presented
tomorrow at the TRIUMF Annual General Meeting. She will talk for 20
minutes on facility development followed by Shawn Bishop for 20 minutes on
21Na(p,g)22Mg and the Na-Ne cycle in novae.