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    User name K. Aniol

    Log entry time 16:11:00 on July11,2000

    Entry number 45598

    keyword=shift summary

    08:00 Moeller measurements in progress, beam ~ 2uA

    08:45 - J.P. Chen requests that we do the e-arm singles at 25 degrees at 1.5,0.9,
    and 0.55 GeV after the 45 degree runs are finished. After the singles runs are
    completed we should contact M. Stevens, if there is to be a significant accelerator downtime ( more than one hour), to setup the spectrometers for the data production.

    09:30 - switching to compton run

    10:03 - start run 2800 at p_e= 0.55, junk run with machine trips and beam off center
    10:14 end run 2800

    10:15 start run 2801 p_e =0.55 ,th_e = 45.5 deg, beam spot drifting
    10:25 end run 2801

    10:30 start run 2802 notice that the bpm 1h00b shows the beam spot is on target(0,0) whereas spot++ gives a center position of x = +1mm, y = +0.5mm. 1.8M events

    10:38 start run 2803, beam off for half the run
    11:01 end run 2803 0.337 M events

    12:15 discussion with JP Chen to increase ps1 for the 0.55 GeV parasitic run.
    Even with the 0.5uA Moeller runs the dead time is 94%. The beam is off center by about -6.7mm. There may be a large background due to beam scraping the pipe or hitting a frame.

    12:30 increased ps1 to 20 and still getting 94% deadtime at .5uA/Moeller. ?

    1:00 The prescale factor had not actually been saved to prescale.dat. Once beam comes back we can try the run with an actual change in ps1.

    1:30 Closed all the target windows on cryotarg. Restarted target programs as per instruction book. Put charts on clasxt28. Charts are ok now.

    14:00-14:11 runs 2810 and 2811 are "ok" except, because of the Moeller run, the current was at .5uA and the beam was off by x=-.5, y=-6.4, dead time = 3% with ps1=20.

    14:12 switch to compton run.

    14:19 start run 2812 - compton parasitic run - bpmx = -.05, bpmy = .4
    at 66uA, ps1 = 100, dead time = 0%, coda = 2060 KB/s , 1.69M, end at 14:33, pe= 0.55

    14:34 start run 2813 bpm, x=-.07, y = .29, ps1 = 50, dead time = 1% coda rate = 4100, pe = 0.55, end run 14:44, 1.8M events

    14:44 start run 2814, end run 14:51, same as run 2813

    14:52 start run 2815, end run 14:59, same as run 2813

    14:59 start run 2816, end at 15:06, same as r2813

    15:07 start run 2817, end at 15:14, same as r2813

    15:14 start run 2818, end at 15:19 with 1.05M events, same as r2813

    Good compton runs for pe = 0.55 at th_e = 45.46deg are runs 2812 through 2818

    16:00 moved electron spectrometer to 25 degrees 24.97 deg (25floor, 30vernier)
    and change the momentum to 2.7 GeV. Discussed with JP Chen and Rikki. Rikki's calculations for 25 degrees are

    W..........pe
    1.9........2.7
    2.6........1.6
    3.0........0.85

    Do the pe = 2.7 GeV point during the next compton run. The remaining two points may be done during subsequent compton runs if the spin dance goes to 8:00AM on Wed. morning. In any case, take data even during the Moeller runs.