User name I. Shin
Log entry time 16:19:26 on January 28,1999
Entry number 267
keyword=Charge survey for BCM2.Here are Beam Charge survey plots for BCM2.
In figure 1, there are two guys which are obviously strange. Those run number are
17029 and 17360. We got the good yield for 17029 with Beam on current Q_tot in
stead of BCM2 Q_tot. Run 17360 might have long pause of beam.
Followings are from gen17360.txt. BCM Q_tot is quite different from Beam on current Q_tot.
I_avg Q_tot Q_tot
(microAmps) (microCoulombs) (microAmp-hours)
BCM1 2.916 2118.689 0.589
BCM2 2.964 2153.535 0.598
BCM3 3.774 2742.709 0.762
***********
* Beam On *
***********
Threshold = 5.0
Beam on time = 25.78 sec ( 3.5 % )
I_avg Q_tot Q_tot
(microAmps) (microCoulombs) (microAmp-hours)
bocur 89.374 2303.823 0.640
Figure 2 is more closer look of figure 1. It seems that every charge ratio are smaller than or equal to 1.
Figure 3 was made to see whether correlation exist between time and charge or not.
The charge ratio decreases as time ratio decreases. We need not care about the one
run which is located at roughly (0.86,0.99) because it is not Physics run.
Charge ratio not equal to zero is largely due to current monitor offset when beam is off.
Conclusion : We should use gated charge.
And we will use smaller threshold than 5.0 micro Ampere in replay_4.FIGURE 1
FIGURE 2
FIGURE 3
