User name riordan
Log entry time 15:09:17 on March 20, 2006
Entry number 167599
Followups:
- 167604 03/20/06 15:29 riordan Corrected Momentum for New Kinematic
- 167606 03/20/06 15:54 riordan Time of Flight Cuts
Rob and I worked on extracting the number of elastic events from the
combined runs 3088 and 3089. We first started by making the appropriate
corrections to the momentum (which as not been calibrated for our new
kinematic). The momentum difference between what we calculate and what
we expect from electron scattering angle versus focal plane x is in figure 1.
We then confirmed a coplanarity cut using the shower X and neutron arm
cluster X (figure 2). The red squares represent the selection for the cut.
Then, looking at the momentum difference, we looked at the effect of
adding in a time of flight cut, which did not appear to reduce what we
found from elastics, but did reduce background. (Figure 3)
We found from a fit that we had approximately 525 elastic events in
figure 3. I will continue to look at how many elastics we find strictly
from the BigBite to find the efficiency for the neutron arm.
Figure 1 - P_diff vs FP X
Figure 2 - Coplanarity Cut
Figure 3 - ToF cuts
