User name X. Zheng
Log entry time 17:00:01 on June 7,2001
Entry number 62379
Followups:
keyword=3He elastic rate from ref.cell run #14383He elastic rate from reference cell run #1438:
run time: 19.5 minutes;
beam current: 10 microA;
ref cell: 3He, 68 psig, 5.6 amg.
Total events: 394133, rate(pres/real)=337Hz/673Hz
Window: 256386, rate(pres/real)=250Hz/500Hz
3He total: 89038, rate(pres/real)=75Hz/150Hz
3He cut in elastic momentum: 10658
-> from 10658 events, estimate contribution from QE is about 55%, so about 6000 events are real 3He elastic events.
-> 3He elastic rate(pres/real) = 5Hz/10Hz
Estimation for 3He elastic asymmetry:
with beam current 15 microAmp, target 10 atm:
Window rate: 750 Hz
3He total: 405 Hz
3He elastic: 26.8 Hz
Estimation in run plan:
prescale 12, 3He elastic rate 40 Hz,
total 13.3 hours (effective time = 8.0 hours) for 3%.
Estimation from this run:
prescale 1, 3He elastic rate 27 Hz,
total 16.2 hours (effective time 9.7 hours) for 3%.
Two plots:
left: spec_l.p, cut in reactz=(-0.9,0.9), it shows big QE and small elastic peak.
right: spec_l.reactz, window contributes about 70% of total events for this run.
FIGURE 1
FIGURE 2
