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    User name LeRose

    Log entry time 11:59:34 on October16,2001

    Entry number 74827

    keyword=Left Arm max P0

    10:20 set P0=4.1 GeV/c
    10:35 just as all three quads reached 4.1 got a quench fault in q2 (Mark is investigating)
    q1: 3085 amps
    q2: 0 amps
    q3: 1632 amps
    10:54 dipole reaches 4.1 (1556 amps)
    10:56 set P0=4.2
    11:00 q1 and q3 reach 4.2
    q1: 3160 amps
    q2: 0
    q3: 1672 amps
    11:10 lost q1 He level went to zero abruptly, Mark says there's also a DC overcurrent failure which he's never seen before. The overcurrent emergency shutoff maybe what's causing the sudden He loss. He'll check it out after he finishes with q2, which he says is almost ready.
    dipole reached 4.2 (1615 amps)
    11:33 q2 is ramping up. The word from downstairs is that it's fixed. q1 may have a serious problem (a hardware failure that's causing an interlock trip arbitrarily. Mark went to get "the book", which Ed says is never a good sign)
    11:38 q2 reaches 4.2 (1809 amps)
    q3: 1672 amps
    11:40 going to 4.3 (without q1)
    11:42 q2 and q3 reach 4.3
    q2: 1852 amps
    q3: 1712 amps
    dipole is ramping
    11:46 report from the Hall: Problem on q1 power supply is that the DC overcurrent set point has drifted and needs to be adjusted. (Question: is this a symptom or the cause? We shall see.) Adjustment will require running the magnet up to max current so we're leaving the other three energized at 4.3.
    11:47 lost q2 again!
    11:55 Dipole reaches 4.3 (1677 amps)
    Tech's are going to lunch, me too!

    FIGURE 1

    FIGURE 2