Minutes 2006-03-14
begin 14:00
present DFOT,DH,JC,CR,MT,CP,GR,PM,AH,CV (recorder)

1) last week's minutes:
   concerning 24Mg(p,g) for 26Al(p,g): resonance energies are ok, 
calculated resonance strength was off  (query from Uwe Greife)
   some misspelling of peoples name

2) alpha acceptance:
   JP reports:
   measurements at the tail end with MCP in (as it was for the 26Al run) 
 showed only 15 mrad acceptance, could be reproduced with GEANT and 
 realistic alpha source energy distribution.
   moved DSSSD back to charge slits to investigate larger y distribution, 
 now closer to the focal plain. He shows a plot of sigma of y-distribution 
 vs. Q1 detune (attachment1.pdf). A minimum was found at a 5% lower Q1 
 field. According to Sabine's thesis the strength of Q1 was increased by 
 10% compared to the original tune, but mainly to achieve a first order 
 focus in x according to the wobbler studies. 
   DH dug out some numbers of Q1/Q2 Hall probe ratios:
     GIOS+field maps:          1.03
     standard tune on web:     1.05
     run15419 (40Ca in Aug05): 1.01

3) upcoming beam times:
   DH: at Monday's internal ops meeting Bob said they wouldn't be ready to 
 take beam for ISAC-II development before end of next week or Monday the 
 week after (March 27), but that was the time scheduled for Keerthi to 
 start with 40Ca. The plan now is to start with 40Ca next week and keep 
 running until ISAC-II development is ready, and to continue the time 
 after. Keerthi is on vacation this week, but is reachable and will 
 probably start on Friday with 40Ca.
   DFOT: Preparations for 40Ca can be done in 1-2 days, which includes 
 installation of final turbo at the gas target (TP7), fixing leak 
 (requires some leak checking) and installation of CSB.
   PM: roots blower fan, the cheaper solution would not be ready for the 
 next run
   DH: alpha test should be stopped Friday morning to have enough time 
 for preparations.
   Bob and/or Marco should be available for tuning early next week. 
 There is a good chance to see beam on Tuesday.
   JP: for the remaining thee days of alpha acceptance studies the plan 
 is the following:
        1) at charge focus: varying Q2 at some Q1 settings, varying Q1 and Q2 
	by the same factor
        2) Wed move to mass focus: check the tune there
        3) Thu move to tail end: check the tune there
   CR: wants to finish GEANT simulation for 26Al with different Q1 settings. 
 It seems like the transmission is not dramatically affected because the 
 angular distribution peaks at a few mrad and only a small tail is above 
 15 mrad, mainly because of the cascade transition. After that he wants to 
 run a batch job for alpha studies for comparison with the measurements.
   some discussion about what are the right parameters to look at, setpoint, 
 readback, measured field, max. field, pole tip field... EPICS scales only 
 setpoint, but actual field should be checked.
   CV: there are two settings for the Hall probe, 2 kG and 20 kG, the field 
 output differs up to 2%.  

4) 40Ca run plan:
   CV: shows refined R-value plot from Nov05 run. CV checked a few runs 
 (attachment2.pdf) and got a tighter distribution, CO found a bug in his 
 code and both evaluations agree now. A slight dependence on pressure is 
 visible (higher R-value at lower pressures). Not sure what the cause is. 
 He also shows a short outline of preparations and run plan 
 (attachment3.pdf). 
   Effective target length should be measured with small apertures at 
 entrance/exit of gas target cell. Could be combined with ISAC-II beam 
 development because it requires some modification at the target.

5) AOB:
   JP: we have to move several GBs of run data (mostly from E989 and E1024) 
 on ibm00, because DRAGON was the No. 1 user. Files will be moved before 
 the next run to a new disk which is not backed up. However, data files 
 are still on isdaq04. If the hard disk is full a new one should be 
 installed, since they are cheap now and more convenient than tapes.
   JP: the window manager (roody) was updated, should run more stably now.
   DH: EPICS for DRAGON will be updated this week.
   CR: York solar cell could be tested during 40Ca beam time since MCP ladder 
 is not used.
   JR: Safety was checking 'our' sources, apparently a 60Co source is missing

6) Items for next week’s agenda:
   alpha acceptance studies
   discussion about draft of 26Al paper

end of meeting 14:45