DRAGON Meeting 13.12.05

Present: JDA (John D’Auria), DFOT (Dave Ottewell), MT (Mike Trinczek), CR (Chris Ruiz), GR (Goetz Ruprecht), 
PM (Peter Machule), LB (Lothar Buchman), JP (Jonty Pearson), AP (Anuj Parikh), CV (Cristof Vockenhuber), 
LF (Lisa Fogarty) – recorder

1)	Minutes of previous meeting
Approved

2)	Status of Hardware

JP – BGO HV module which provides PMT HV is dead.  JP will replace it.

PM – Fan on one of the Roots blowers is still broken and needs to be fixed, cannot be done while running 
and so will be done in January.

The new slit shields as installed during 40Ca run will remain in place.

JDA – Leak on the quads? PM – This has been fixed.

The solar cell is in to be tested for TUDA.

DH (absent) wants to put the 30 degree Si detector in the target.

The upcoming run will use the ion chamber and the normal gas target windows (with H2 target)
CV wants to run also with He2 and with the 1.5mm gas target windows to determine the effective length of 
the target.

DAQ for the ion chamber will need to be put in place.
Isobutane for the ion chamber will be sorted out also.

The run will start Thursday morning (15th) and run until Monday morning (19th). The beam is mass 31.

3)	E1024

The operators say they performed 52 energy changes for the 40Ca run! Kudos to them!

CV – The run went well and the beam was very good. A 1mm beamspot was obtained. Unfortunately this seemed 
to punch holes in the SiN foils quite quickly, whereas with a more dispersed beamspot the foils lasted for days.
The experiment went lower in energy than the previous prompt gamma measurements and some resonances are seen 
at these lower energies.
Two more weeks of running would be useful to even lower energies.

CV – beam centering on the slits is now possible since the shields were installed but there is a negative 
offset that makes it hard to see the balance point, so a striptool was used also. Possibly we could redesign 
the shields?

JDA – What is the status of the new “laser-plasma ablation” stripper foils?
CV – Implementing them requires a change of procedure.

4)	E989

Mini-meeting held yesterday. Discussed Normalisation, Events Analysis, Plan for the CSD measurements and 
Publication.

Normalisation is under control, all that remains is the scaler timing factor, LF has done this.

The separator efficiency: In GEANT the separator is 1m shorter than it should be. This is probably some kind 
of bug.

CR repeated BGO efficiency calculation done by Heather Crawford during the summer. The efficiency is about 68%.

AP has been analysing the 27Si events using two different methods and they are consistent.

Publication: will depend on the number arrived at for the resonance strength, which depends on the CSD 
measurements this week.

5)	Plans for 2006

12C(alpha, gamma)
40Ca(alpha, gamma)
17O(alpha, gamma) – given medium priority and all shifts asked for by the EEC.

6)	AOB

JP – the timing problem with the scalers affects all data. The scalers should not be used for timing 
information.
JP added new code to account for pauses in the run, this should be good to 10s, but may be good to 5s.

This affects the 21Na experiment as the scalers were used for timing in calculating the normalising “R” 
values.

Meeting Adjourned 11:20