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User name T. Badman
Log entry time 01:41:48 on December19,2011
Entry number 360842
Followups:
keyword=bcm scaler issue on LHRSI have produced a plot of charge asymmetry in upstream BCM vs. event number (figure 1) for LHRS run number 1924. At around event number 9200 the helicity+ BCM count jumps substantially. I looked in the raw data file for this event and noticed that there is indeed a helicity+ jump at event 9200 in agreement with the plot.
It looks as though the hex value 0xFFFFFF is being added to the ring buffer for both BCM up and down at random (also seen in the raw data file), this value is also being added to either plus or minus gated BCM scaler depending on the helicity state.
Ungated BCM scalers, RHRS and third arm look normal, this looks to only be caused by the SIS3801 for LHRS, possibly a bad module?
This also makes sense of the problem with LHRS end of run halog posts.
FIGURE 1
