User name choi
Log entry time 15:21:16 on January21,2003
Entry number 92824
This entry is a followup to: 92269
keyword=beam halo studyDue to some worry about beam quality, I have checked a few empty target runs using left spectrometer. Here are list of runs I checked with kinematic settings.
Run Color p_left beam_energy comment
20295 Black 2.35 4 supposedly good tune on Sunday Jan. 12
20337 Red 2.76 4 tune has been modified compared to 20295
20389 Blue 3.20 4
20455 Magenta 3.20 5 pre-buncher was OFF
The plot shows "normalized" yield, that is, I have divided by total charge. Right panel is just a blown-up plot of the left panel. In short, three colors (red, blue, purple) are consistent while black shows higher yield from the center of the empty reference cell. There is kinematic change (p_left from 2.35 to 2.76) which may explain why black curve is much higher than the other ones. Turning off pre-buncher seems to have very little effect (compare blue with purple although they are at different beam energies).
FIGURE 1
FIGURE 2
