Minutes Dragon Meeting March 13th 2007

present: DH, CD, JDA, LB, PM, CR, MT, GR, DFOT, CV (recorder)

begin 14:00

0) previous minutes:
  correction of the correction: source has to move 2cm in order to account for the 0.2% change
  JDA was here, but not DH

1) hardware
  linear drive: Don Dale has been contacted for implementation in EPICS. DFOT hast a solution 
for the external mount.
  Vacuum dips: DH is recording vacuum activity in final slit box. Strange dip around 4am has 
been observed.
  Turbo @ low speed: engineering change request to fix two things: 1) low speed light yellow, 
not red; ignoring the false error message from controller causing EPICS to turn off the turbo. 
2) documentation on valve interlock logic.
  Quad fixtures: received from the shop, DH tested one.  Next step: mounting on devices.
  Auto mode: PM had one incident where he couldn¡Çt turn on backing pump in auto mode, although 
no interlocks were unhappy. We need to find the fault to investigate that strange behavior further.

2) 40Ca(a,g)44Ti
  CV presents semi-final results:
  Excitation function shows good agreement between the results from different beam times (except 
on a few points).
  Reaction rate from DRAGON is about a factor of 3 higher than the rate derived from prompt 
gamma studies. AMS rate (Nassar2006) is higher, but within the uncertainty band of the DRAGON 
rate in the covered temperature range.
  Measured stopping power is 10% lower than SRIM2003 predicts. Should also influence the AMS rate, 
which was calculated using SRIM2003.
  Next step: comparison of CV¡Çs results with CVO (has not finished yet). Implementation of the 
new reaction rate in network calculations (will be done by Lin-Sih The from Clemson).

3) Lifetime measurement of Au isotopes:
  GR presents preliminary results
  (Rolfs published a 4% longer half-life in a pure Au sample cooled to ~10K)
  an irradiated Gold sample has been received from Dresden. Was shipped by Lufthansa Cargo and 
arrived 48h after the irradiation at TRIUMF. Activities of 196Au (strong) and 198Au (weak) are 
present. The decay curve of 198Au seems to be a little longer after one half-life (2.7 days) 
but it¡Çs too early for a final result. A reactivation with neutrons will be necessary.

4) REA
  TUDRAGON: drawing went in shop last Friday, must be ready in four weeks (beam time starts Aril 17). 
Top lid will be provided by Edinburgh, detectors are coming from York.
  UWash chamber:  Corri is working again. Pdfs of the drawings were send to UWash, some minor 
concerns of machining CF, support structure and cryo pump. Looking for a 12x8x8 standard box to 
speed up process. Lena will be contacted for safety report.

End: 15:30