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User name mhuang
Log entry time 20:07:40 on April11,2012
Entry number 372814
Followups:
keyword=Only see half of the events with second right septum settingThis is dp=0% optics run from second right septum setting (5-4-2 coils in up-right, same 2-6-6 coils in bottom-right).
If cut on vertexZ, you can only see top half of sieve slit holes (negative tg_th is top). This means only events going through top half part of septum eventually got to HRS (Figure 1).
If plot sieve hole without any cut, you can see almost full pattern, but the down part of holes are from downstream scattering (larger Vz than in Figure 1) as in Figure 2.
I am guessing this is because we set the current to compensate the missing coils in top right septum, but this caused bottom part field too intense to bend the particles into HRS.
So tonight with this new right septum setting (bottom part stayed the same, top part 5-0-2 coils), we will do septum current scan in wide range to see if we can have events from both part into HRS.
FIGURE 1
FIGURE 2
