DRAGON Meeting Minutes 02/01/2007

Happy New Year!

Present: DAH, DFOT, CV, MT, CR (Recorder), PM, JDA, LB

0. Business arising:

        - DFOT to contact Mitutoyo regarding new linear drive measuring 
device with battery powered memory.
        - EEC results Apparently there is a new classification system for 
experiment priorities. 25Mg(p,g) and 33S(p,g) got medium priority, while 
18F(p,g) got medium-high priority. 

1. Hardware:

        - ED2 negative bias tripped off over the holidays for unknown reasons, 
but is now back on.
        - final slit box vaccuum is sitting at 3.5E-07 Torr (n/inc DSSD box).
        - It was discovered (by R. Kietel) that our left and right QSLITS had 
different smoothing-time constants in EPICS!!! No-one knows why this was 
so, although since controls are the only people capable of doing this it 
cannot have been a mistake on our part.
        - Under 'budget' item on next weeks agenda, we will discuss possible 
new hardware items.

2. Alignment/acceptance:

        - From Dave H's tests, results seemed to suggest several elements 
may be off axis by 1-2mm, though steering and correction algorithms 
compensate for this. 
        - Also, pointers to fact that MD1 may be slightly tilted, throwing 
beam 'uphill'. This is a small effect, but will be checked anyway using a 
bubble level by Dave O. 
        - We also require an LED or similar device to enable checking the 
gas target alignment using the CCD telescope when the box is under 
vaccuum.      

3. 22Na target box:

        - Several comments on the design were made by the Seattle group.
        - One concern is to reduce the number of o-rings by welding the box 
rather than having faces bolted to a frame, as  is standard. The box would 
need to be stainless steel therefore. The concern was that o-rings would 
contribute to         outgassing, although it should be noted that the Seattle 
beamline appears to have cold traps installed. 
        - One other issue was that the downstream end of the chamber must 
detach.
        - The question was asked whether or not the gate valve operation 
would 'jolt' the chamber since there is a hard mechanical contact between 
the two. 
        - The cold straps connecting the upstream and downstream shrouds 
had no bend in them in the drawing, leading to the concern that on cooling 
they may move the shroud(s) out of alignment. LB suggested using copper 
grounding cable.
        - The whole weight of the shroud is supported by the brittle 
insulators, as pointed out in Kurt Snover's email. 
        There are various design solutions for this which will be 
investigated when our designer returns. 
        - PM suggested widening the pipe between the box and the gate 
valve to increase pumping speed, ie, avoid 'throttling' down the aperture 
as it is at the moment. 
        - The digital electronics from St Mary's University are at TRIUMF 
and will be tested using the 22Na lifetime experiment setup.
        

4. Other Business:

        - Solar Cell detector (REA 747) to be left on the sidelines for now, 
since DSSD x-y stage is being designed.
        - The TUDRAGON job is also a higher priority.
        - RIA Workshop - Chicago: J. Blackmon requested Dragon figures (26Al 
specifically). 
        - Several conferences this year which should be considered, 
e.g. FINUSTAR (Crete), EMIS (Normandy).
        - 40Ca: need to check with C.V.O to see when draft is going to be 
available - perhaps this month?
        - 22Ne: need to extract some useful info out of this in the near 
future (MT).