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User name A. Puckett
Log entry time 18:20:37 on October25,2006
Entry number 188273
keyword=And off we go!
Starting with run 1753, we have downloaded the trigger for the 4He production settings, adjusted prescale factors so that T1-4 are roughly 10-20 Hz each, PS5=1, and the T5 rate with 60 microamps on 4He is roughly 240 Hz. At this rate, the goal of 154M conicidence triggers will take approximately 7.4 beam-days at 60 microamps. Right now 80 microamps would be too high because we only have ~10 W of spare HPH capacity on the target at 60 muA to keep the temperature constant. Some of the runs we took are bad:
1748: spot check, current scan to find heat-load current limit on 4He. Otherwise junk, we are still trying to recover left arm dipole
1749: Junk, still recovering left arm dipole. During this run, the NMR regulator started working inexplicably, I'm not sure what we did to fix it, but now it's fixed and we don't have to change it anymore. Stopped the run.
1750: FPP straight throughs. The carbon doors were open. the T3 rate was about 10 kHz, so I set PS3=5, PS5=1, and all others "infinite". We got 2M events in ~15 minutes.
1751: FPP doors closed, forgot to download new coin. trigger. JUNK
1752: Downloaded coin. trigger. Forgot to set prescales right. JUNK
1753: Set prescales so that, roughly speaking, T1=T2=T3=T4=10 Hz. PS5=1 and T5 is roughly 240 Hz. Checked online replay, coincidence spectra are sensible. It appears we are going smoothly now and production data are incoming!