Operators: clasie degrush yxiao
Continued data taking from last shift with unpol H2. After taking two H2 runs, the target gas was turned off and the transverse holding field was turned on. The wire chambers still had a small signal:noise ratio even after turning them off for more than an hour. This ratio was 1:4 to 1:3 in the worst superlayers ( r_0, l_0, r_3 and l_3) and 1:1 at best.
There were problems with the left beam slit and with the holding field power supply:
The left slit jammed in the "in" position. CCR could fill with this in, so we continued anyway. The slit eventually moved during a run (junk run 3095), however, it moved very slowly. The detectors would finish ramping up voltage before the slit had moved into position. The left slit is now kept at the setting -2.53 during and after fills.
When the holding field was turned on, it was at 504A (transverse only) and the holding field readout was Bx=203G, By=120G. During a run (junk run 3096) the holding field current dropped to 499A as checked in the D-tunnel and the holding field readout INCREASED to 451G, 272G. CCR noticed this first by seeing a jump in the power supply current readout in the control room. The beam was retuned for the 499A setting.
With these conditions (left slit fixed and 499A transverse holding coil current), run numbers 3098 and 3099 were taken.
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