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    User name E. Schulte

    Log entry time 08:03:20 on February 12, 2007

    Entry number 192498

    keyword=2/12 Owl Shift Summary

    00:00 Started shift on Kinematics G with B4C target in place. Some discussion about the plight of the poor HRS-R VDC's lead the current to be reduced to 3uA to keep the current to about 10uA in the HRS-R VDC's. This reduced the HRS-R rate to about 160kHz. Alexander, who is despirately trying to figure out the "dead time problem" would like the HRS-R rate at about 4kHz, but short of putting in the sieve, that just isn't happening.

    01:08 Request change of target to Li.

    01:15 Request 3uA back from MCC. Start production on Li target. Check rates at 3uA & prepare to request 5uA.

    01:18 Request current increase to 5uA. HRS-R rates about 65kHz at 3uA.

    02:28 Request target change to Ta & move spectrometer to Kinematics H 55.5 degrees.

    02:37 Finished configuration change and requested beam back at 15uA.

    03:18 Alexander requests that the prescale for T4 be investigated as the source of the dead time issues we've been seeing. He requests that for a high rate target (carbon or boron carbide) we take a short run with p4=1 & then pre-scale p4 away to see if there is a change in the reported value.

    04:41 Complete Ta running & request target change to carbon.

    04:43 Complete change of target & request 10uA from MCC.

    06:10 MCC called to let us know they have lost the beam and will need several minutes to get it back. Stopped run #6239 at 20 minutes completed (second 1hr file). Will re-start when beam restored. They performed their "QE" at this time--perhaps this was the problem...

    06:26 MCC called to let us know that they were getting ready to send beam back. We requested the settings as before 10uA.

    06:42 Beam Back! Started new run #6240

    07:00 Lost beam again. MCC working on problem. Ended run #6240. Run has several minutes with no beam at the end.

    07:14 Decided beam looked OK enough (positions & current) to try restarting the DAQ again.

    07:56 Request switch to B4C target.

    08:00 Ended shift trying to get the B4C target in place, MCC forgot to mask the FSD!