User name R. Michaels
Log entry time 00:25:41 on October13,2005
Entry number 156686
keyword=cranked HV on Left Horiz.Increased HV to 2100 (increase of 200V) on Left Horizontal segment.
See cosmics in scalers now (1 to 3 Hz).
For 0.2 uA we see rates on L-arm
Vert. Segment 12 kHz
Horiz. Segment 1.3 kHz (1/10th)
On R-arm the 2 segments are more balanced, about 75 & 83 kHz
Crank HV on L-arm Horiz another 100V to 2200V.
Vert 13 Hz
Horiz 2.2 kHz
Run 2817 with dP = -2% on L-arm, but dP = 0 on R-arm.
P_L = 3.0654 still.
P_R = 3.1776 (new optimum)
Wrong prescales on T2. Run 2818 is a repeat with better PS.
Now its clear the L-arm Horiz segment makes a signal (fig 1)
but the amplitude is way out of whack (1/5 th of other 3 PMTs).
David L. wants to take access to remove a filter.
We could probably do the alignment with this unbalanced rate
(would need a slightly more careful offline analysis to avoid
bias from the dominant detector) but we decide its best to
verify we understand what the detector is doing ...
I (Bob) am leaving now. Rob F. to take over this part.
FIGURE 1
