Minutes of DRAGON meeting  April 6, 2004


Present:  JdA  MT DO(recorder) JS PM CJ ML DH JC DG AO LB MP CR

Action:   A green crystalline crud  was found in turbo pump cooling 
circuits. It was removed and fresh water replaced.  Glen Battersby 
suggests that we put in resin and
monitor its condition with a conductivity meter.  JdA to get the green 
crystals analyzed.  Since the replacement of the recirculating pump,  
there are now brass fittings in the circuit that may be a cause.

We have quotes on a new elastic monitor silicon detector; we will order one.


12C(alpha, gamma)  progress   LB

The problem is in the larger acceptance, the 80 mR emittance of the 
recoils versus the 25 mR acceptance of the pumping tubes.  This shows 
up as asymmetry in the BGO's that changes over time.

Discussion ensued over where the losses are occurring, in the pumping 
tubes or the separator.

DH presented a simulation of +/- 2 mR steered recoils that put an 
odd/even asymmetry
in the BGO's.   A 5/3 mR steering was introduced in runs 12070 and12071.  
These results
failed to reproduce the simulation.  More counts were introduced into the 
positive side, the sign was correct, but odd even did not reverse, just 
changes in relative heights of the odd even peaks.

The problem seems to more fundamental than just a mistuned separator: 
something more is happening.

The scaling program may have problems, it was observed to predict 
different NMR values for identical energy/mass/charge values.  
DH to check out.

Simulations have been crashing due to IBM00 problems..May have to move 
to Westgrid?

Our best tune results in a huge asymmetry in the forward looking BGO's.  
Since we do not know the emittance, we could turn off the quads and see 
what slit settings allow 95 percent of the beam through.  There was 
discussion of the effect of  4mm entrance /10
Mm exit of the gas cell, compared to previous 6mm/8mm.  This may have 
a different density distribution of the gas.

26Al (p, gamma)  CR

The ion chamber may have separation problems, so the use a 2nd MCP  
and the DSSD was put forward.   A scintillator to look for delayed 
beta was talked about.

Radioactive Beam   The TUDA time of 4 days starting 18 May may be available.
The choice will be 26 Al or 21 Na.

EEC  7 May  Who presents what.  

Beams   If ECR fails, then only beams for next year will be 26Al or 21 Na.