Minutes of DRAGON meeting, 16 March 2004

Present: John D'Auria (JDA), Art Olin (AO), Jonty Pearson (JP), Lothar Buchmann (LB),
Goetz Ruprecht (GR), Dave Hutcheon (DH), Dave Ottewell (DFOT), Alison Laird (AL),
Cybele Jewett (CJ), Chris Ruiz (CR), Doug Watson (DW) - York, Josh Slater (JS) - recorder



1. Correction to Previous Minutes:

Minutes of 9 March 2004 were accepted without change



2. Facility Status:

DFOT - Elastic detector will be in for C12(a,g)
     - New 55 degree holder was made and mounted.  "Looks good"
     - Needs pre-amps for it though
AO - Questions whether shield will be in for the run, whether shield makes a difference
JDA - suggests retesting the shield during the run

DH - Readout on final Faraday cup dead on one channel, switched to old style, works again but 
     factor 10 less beam measured.
   - EDs running low voltage for weeks now, need conditioning.



3. Status of C12(C12,g) run:

DW - Thanks everyone with DRAGON who helped with the run.  Calls the run "reasonably successful".
   - Looked at resonances in paper, 6, 6.5, 8 MeV, data taken for each.  Data taken off resonance 
     as well between 6 and 6.7 MeV.  Hopefully more off resonance data tonight.
   - Each resonance appears to decay to same state, as peaks shift with beam energy
   - Appears to be an asymmetry in BGOs triggered in coincidence with recoil detection.

DH - More counts on the NorthEast hemisphere than SouthWest hemisphere.  Reason unknown.       
     Suggestions JS look at it in GEANT simulations

DW - Most data has been moved to York already, but asks DRAGON not to "ZAP" the data yet.
   - JP has been helping David Jenkins with data programs
   - Plan is to do data analysis and publish quickly



4. Tentative Plans for C12(alpha, gamma) run:

LB - Run starts on Friday March 26th.
   - Carl Brune (Ohio University) sending a graduate student, Catalin Matei, who also wants 
     to take data.

Tentative plan circulated in meeting agenda:
        1. Go to 1.764 MeV/u. check system 
        2. Get elastic counters working. 
        3. Long runs at this energies..check acceptance, 
           check, if yield stays constant (e.g. after foil changes) 
           obtain very good statistics both in recoils and gammas. 
        4. Go in 30 keV/u steps to highest energies. 
        5. Back to 1.764 MeV/u. Check yield. 
        6. Move down in 30 keV/u steps to 1.63 MeV/u 0+ resonance. 
        7. Good statistics run on 1.63 resonance. 
        8. Continue stepping in 30 keV/u steps towards 1.45 2+ MeV 
           resonance (may skip one or two steps nearby resonance). 
        9. Good statistics run at 1.36 MeV/u. 
        10. Good statistics run at 1.29 MeV/u. 
        11. Good statistics run at 1.22 MeV/u 
        12. good statistics run at 1.13 MeV/u. 

LB - Wants the DSSSD, not the ion chamber, to resolve angular distributions.  MCP not needed either.

DH - Asks whether the time of flight was looked at for "funny" sets from previous run
LB - Hadn't looked at TOF, but looked at centroids of peaks, unsure what caused the puzzling data.

JDA - will work on shift schedule for the run.  Plans on 1 person/shift, with DRAGON flying 
      on her own overnight.  JS, GR, JP still on learning curve and schedule will reflect that.
    - Mike Trinczek going to be working on GEANT simulations of C12(alpha, gamma)

DH - side note, custom software ordered for ccd camera.  Some new features, such as ability to make 
     larger apertures to integrate across bull's-eye and subtract background, logging to disk 
     after X seconds.


Meeting ends with some discussion about which ion source is best for DRAGON if ECR doesn't work.  
     Laser ion source (for Al) seems to be best choice, but negative source could also be used 
     for F beam.