Minutes of January 30, 2002 DRAGON meeting

Present: DH(recorder), AC, AL, MC, SE, DL, DG

1. Minutes and business arising
	Correction to minutes of January 15: Uwe Greife's submission to
EMIS is on measuring beam properties, not gas target performance.
	Correction to minutes of January 22: "BCM1 was found to be about
1.25mm high"

Business arising from January 22 minutes:
* BCM6 has been fixed by PM.  A signal wire had come loose inside.
* ED1 power supply problem (tripping) was investigated, but no cause
positively identified.  Anode and cathode supplies were swapped and no
trip happened in the following 1.5 hours.
* the MCP was installed and tested with a Gd source.  Cables have been
run to the main electronics racks but not yet connected to ADC,TDC.
* re-survey of the gas target cell and tubes showed that the cell was not
rotated, as had been thought at the time of the previous meeting.  There
is 0.5-1.0mm shift of the cell to the SW of the survey line and also
relative to the nearest pumping tubes.  The cell and the pumping tubes
nearest to it are 1.5-2.0mm higher than the survey line, as is the
farthest-upstream pumping tube; the farthest-downstream tube was 0.5mm
high.  Because the cell was not rotated and the discrepancy relative to
nearest tubes on order 0.5mm, there was no attempt to adjust the cell
relative to the target vacuum box.  Surveyors measured the elevation marks
at the north and south sides of ISAC Hall to be the same within 0.1mm, so
the vertical discrepancies are not likely sinking/rising of the Hall.

2. Status/plans for the present stable beam runs
* beam energy calibration runs on the 1160 keV/u resonance in
20Ne(p,g) have been done at 2 energies.  For smallish pressure changes the
z-mask centroid sometimes shifted in the 'wrong' direction -- need to
investigate whether this is statistically signifcant and, if so, how it
could happen.
* plan is to complete the energy calibration tonight, then start the yield
measurements at 1160 keV/u 20Ne(p,g) tomorrow (Thursday).  It sounds
unlikely that the L-bend needed to run 24Mg will be ready for installation
during today's Maintenance, but could be done early next week.  Our run
plan  has at least another 2-3 days of work that can be done with Ne
beams, so the L-bend is not yet a hold-up.  After the 20Ne(p,g) yield
checks, the plan is to revisit 21Ne(p,g) at 265 keV/u for comparison of
old-vs-new quad settings and to diagnose source of leaky beam.
* SE will analyze last night's data for a quick Quality Assurance check on
our method.

3. Other business
* DH measured the voltages across Q9, Q10 coils (before the Q10 P/S died
and was replaced by a temporary supply).  Voltages plus resistances
measured during field-mapping indicate true currents approximately 1.4
times the currents indicated in EPICS.  This would explain the
"low" Q9/Q10 settings (relative to GIOS theory) which we needed to get a
focus at the Final slits.
* there are nearly 40 applicants for the DRAGON summer student job.  DH
and AO have made successively shorter lists and AC currently has the
file.   Another process going on at the same time is placing 'scholarship'
students, and there is a good candidate who is interested in DRAGON.
We want to be able to have a challenging project for at least some of the
student's time.  The overlap of student availability and beamtime to
DRAGON is only 2 weeks, in mid-May; we should look into having a TUDA
student take part in DRAGON beam runs and vice versa.