Subject:Minutes of DRAGON meeting Oct. 8, 2002
From: Joel Rogers
To: Dragoneers

Attendees: J.D'Auria, D.Hutcheon, C.Jewett, D.Ottewell, J.Rogers

!. Minutes - of previous meeting were accepted without revision.

2. Report on recent run (DAH)
 Eprague = 1.059 x Emd1 based on 2 resonances in 21Ne(p,g)22Na.
 This is much larger than before.  It is the first comparison since
 the Prague magnet Hall probe and electronics was changed.

 The 21Ne(p,g) resonances at threshold energies 501 and 521 leV/u are
 appearing 5-6 keV/u lower than the literature values, according to
 MD1 fields.  The same difference was noted in the August IC tests.

 The yields of the two resonances are consistent and repeatable.

 The remaining time will be spent on a 382keV/u 14N(a,g) resonance.

3. CCD beam photo (DO)
 The interior LED light showed the inner cell apertures clearly on
the CCD camera. The beam spot appears to be white and crescent shaped,
sometimes with a tail on the left and sometimes on the right. The beam moves
left and right with upstream steering as expected. It is planned to make these
pictures available to the operators for routine centering of the beam in
the gas cell

4. Elastic time/pulse-height spectra (JR)
 A three-peak structure is present in the elastic pulse-height
spectra (see attached online spectra) and the same structure is suggested by
the time-r.f. spectra. Better time-resolution appears to be possible with
a fast-amplifier + constant-fraction-discriminator which was added in
parallel to the present delay-line amp + CF-TSCA setup. Tonight's data
should verify this improvement.

5. PRL paper exists in draft form on 212keV/u 21Na(p,g)22Mg (JdA)
 The paper needs a section on energy scale calibration. The following
stable beam reactions have been measured to determine the TRIUMF scale, and
should be summarized in the PRL paper:
 15N(p,pa)12C at E = 427 keV/u  (lab threshold energy)
 21Ne(p,g)22Na at E = 271 keV/u
 21Ne(p,g)22Na at Ecm = 763 keV/u
 20Ne(p,g)21Na E = 1160 keV/u
 24Mg(p,g)25Al Ecm = 214 keV

6. Upcoming EEC presentations (JdA)
 Two proposals for new uses of DRAGON will be presented at the Dec. 9
EEC meeting. Lothar will present a proposal for 12C(a,g)16O and Brian
Fulton will present 12C(12C,g)24Mg. DAH has a copy of Brian's proposal in
preliminary draft form. It would require modification of the DRAGON target
box to accommodate a solid carbon target. Lothar's proposal calls for high
intensity beam, about 1 particle microamp of 12C, which requires as high
intensity (gas) stripper be added to OLIS..

7. Summary of present thinking on 15O(a,g)19Ne (JdA)
  A proposal to the EEC is being prepared to address the need for a
connection to the existing off-line source box or charge-state-booster to
receive the 15O activity from the TR-13 cyclotron as a production source.

 Following Barry David's seminar it appears that capture to the lowest
state in 19Ne is not as strong as previously thought. This new information may
require our re-direction to measure higher lying states.