User name V. Sulkosky
Log entry time 00:18:05 on November 1,2007
Entry number 211054
Followups:
keyword=Data with Bad Beam Tune (509 MeV/c)On Tuesday, Owl shift after beam was restored back to 50 uA, the beam
optics was crossed focused at the two BPMs. The spokespersons were
concerned about the data quality.
Here is a summary of the data taken with the left and right
spectrometers at 120 degrees with P0 = 509 MeV/c.
Run_left # 1492 Run_right # 20276 / Helium
Run_left # 1493 Run_right # 20277 / Dummy 10 cm
Run_left # 1494 Run_right # 20278 / Carbon
Run_left # 1495 Run_right # 20279 / Iron
Run_left # 1497 Run_right # 20281 / Lead + Hydrogen
I did the full physics replay for these runs. They can be found in
the /adaql10/work1/E05110/onlana/ directory with file name:
onlphys_xxxx.dat.
Figure 1 shows the number of tracks and event type for run # 20281.
Without any cuts, there are about 600k events. When I place a cut
to require that the events have a hit, there are only about 18,600
events that have at least one track, i.e, only 3%.
Figure 2 shows the delta spectra. The top plot with only cuts to
ensure the event has at least one track and is a T1 event. The
bottom plot is displayed with generally loose acceptance and PID cuts.
FIGURE 1
FIGURE 2
