Minutes of the February 18, 2003 DRAGON meeting

Present:  JDA, CN (recorder), AB, DG, LB, SB, CW, ML, SE, AO, AL, CJ, DH, UG, PM, JR


1.  Minutes

    Several spelling mistakes corrected in February 11 minutes.

    Minutes will now be available online, but it was agreed not to
    post them until they had been corrected and approved in the
    following meeting.

    http://www.triumf.ca/dragon/minutes.html


2.  Status of PRL paper

    There was some discussion among the PRL paper's authors regarding
    the uncertainty in the BGO efficiency listed in the paper.

    There appeared to be a discrepancy in the analysis of the 7.5 MeV
    resonance in the Ne21 reaction, between users of Nova and users
    of MIDAS.  
    
    After much discussion, it was decided to change the efficiency listed
    in the paper from 0.51 to 0.48, and to reduce the uncertainty on the
    systematic error for the gamma array from 20% to 12%.

    See attached.


3.  Plans for stable beam

    UG requested a 21Ne beam at approx. 500 keV/u to re-check measurements
    made last August and test the operation of the ion chamber.

    JDA mentioned that the 13C(p,gamma)14N reaction could run at the same
    time as it would also need to use the ion chamber.
   
    DH mentioned that there may be beam available as soon as tomorrow
    evening (Wednesday, February 19).  This will last until Friday,
    with beam time being used for operator training, and testing of the
    system.  There will also be beam available from March 3 - 4, and from
    March 10 onward.

4.  Mini facility status reports

    a.  Power Supply (DH)

        The new power supplies have been hooked up and tested.  CN is
	currently working out the new field versus current relationship.

    b.  New Faraday Cup (DH)

        The new Faraday Cup still in the milling stage.  Progress is
	moving slowly.

    c.  HV Conditioning (DH)

        The high-voltage conditioning is continuing, though some problems
	with the software have been encountered.

    d.  New Beam Position Monitor (DH)

        The red cables for the new beam position monitor have been pulled
	into place.  The motor controller has not arrived yet.  Will wait
	until next week to proceed.

    e.  Target Wheel (DH)

        The target wheel for using solid targets is still in the design
	phases.

    f.  CCD Camera (PM)

        The CCD continues to stop operating at unexpected moments.  It will
	soon be necessary to update the user manual to reflect recent changes.

    g.  DAQ (AO)

        The DAQ is all set up with updated documentation available.  It
	was decided not to check the VME system.

    h.  Webpage (CN)

        Photos taken at meeting will be placed on the "People" section of
	the DRAGON webpage.

	http://www.triumf.ca/dragon/people.html


5.  Cooling system

    JDA mentioned the need to meet and discuss the chiller on the (DSSSD)
    focal plane silicon detector.

6.  Elastic monitor

    LB reminded us that problems had been encountered with the elastic
    monitor.  JR will work on it.

7.  Faraday cup current integrators

    AL reported that new current integrators were available for the Faraday
    cups.  She has tried them on TUDA, and found that they allow readings
    at lower currents (after some time delay - see attachment).
    
    It was decided to get two made for DRAGON - one for FC4, and one for
    FCCH.