Log entry time 06:19:18 on August26,2009

Entry number 286080

Restricted to 30 uA due to ion chambers.

Run 11646   ovs=0.  Beam up to 30 uA but tripping a lot.
Luis is adjusting HV on Blumi.  Also adjusting BCM gains.

Run 11647 ... same as 46.

Run 11648
BCM1 hi gain, BCM2 low gain, thick tantalum, 30 uA, ovs=0

Plan is to do ovs=0,1,3,7 (i.e. no-oversamp, then x2, x4, x8)
and have a beam ramp in each run : 0 to 30uA in 2 minutes.

Use curmon=bcm1

Run 11649 ... ovs=1
Run 11650 ... same

The runs with ovs=1 show Blumi=100K at start of run, dropping
to 10K after a few min.  

Run 11651 ... ovs=3

Conclusion: Oversampling data is not useful.

Run 11652 ... ovs=0 again
Symptom similar to 11649/50.
Oops !  had rampdelay on RHRS = 200.  Must set to zero.

Run 11653 ... ovs=0 ... Rampdelays all zero.  Now, data looks normal.

So it looks like this different rampdelay, which led to zero
deadtime for ovs>0, is bad for other reasons !

During 11653 we do another current ramp.

Observed poor synch for run 11653 -- in synch mon, but also
lack of tight correlation of blumi to bcm.  Looks like the
ADCs in R-HRS are lagging behind.  Yuk.

06:18 Request access to swap PREX Quartz detector config.