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    Make New Entry, Make Followup Entry

    User name R.M. et.al.

    Log entry time 15:56:17 on November29,2009

    Entry number 303542

    This entry is a followup to: 303537

    keyword=Compton tests, part III

    Persons doing the test:

    A. Camsonne, M. Friend. D. Wang, R. Michaels, O. Glamazdin,
    M. Dalton

    15:22 ... 5 uA CW beam appears. Compton Edet at 40 mm.
    Current drawn on Edet hardly changed between beam on and off,
    but we see "a bit of rate" in triggers. It's pretty clean.

    15:24 .. Need to reboot iochawt1 (IOC for Edet motion).
    Apparently it crashes often.

    15:26 .. Ask MCC to go up to 10 uA. Then close the slits
    to achieve 1 uA.

    Edet moved to 20 mm.

    At 10 uA with Edet at 20 mm, observe 700 to 1000 nA current drawn.

    Slits being closed.

    15:45 .. See 0.8 uA beam. Moving Edet to 10.0 (GUI) which is
    actually about 18 mm. IPM1P02B.YPOS is around -1.0 (ok).
    Edet with threshold of 30 (~15 mV) we see 80 kHz (rather high).

    15:46 ... Start run 21305 ... Electrons only. Thresh = 30 mV.
    Compton photon detector 1725V.

    Expect ~600 Hz signal, so won't see much with 80 kHz.

    15:52 Realized stepping motor was on. Decide to turn it off since
    it causes noise.

    Run 21306 with stepping motor turned off. The rate 60 to 80 kHz.
    Edet still at 10 mm (GUI setting), Thresh 30 (GUI).