• Main INDEX
  • Monthly INDEX
  • PREV
  • NEXT

    User name lkaufman

    Log entry time 00:02:47 on September 24, 2005

    Entry number 155747

    keyword=Large Aq scans for detector linearity (Runs 5315 and 5316)

    Took two scans designed to generate large charge asymmetry, in order
    to better test detector non-linearity. Most methods for generating
    charge asymmetry also generates position differences, but we'll have
    to live with that.

    Each scan covered approximately 1/2 oscillation (peak-to-trough) of
    the 4-theta term in the halfwave scan. A PITA offset delta = -180 V
    was used to turn this into a significant charge asymmetry change.
    This was done for the OUT halfwave plate state for 2 different beam
    currents. The IA cell was set to 5.03 V. Feedback and dithering were
    turned off.Hall C was off during these scans.

    The auto_rhwp macro was used, with steps of 5 degrees and 180 sec per
    point. Scan clean will point to good data at stable set points.

    Run 5315: IHWP OUT, RHWP scan [10,60], PC Pos = 4.75, Neg = 6.81, beam
    current = 37 uA
    Run 5316: IHWP OUT, RHWP scan [10,60], PC Pos = 4.75, Neg = 6.81, beam
    current = 25 uA