User name R. Michaels
Log entry time 00:41:24 on October 11,1999
Entry number 28140
Followups:
- 28144 10/11/99 02:27 R. Michaels Re: strange TDC spectra
- 28147 10/11/99 02:50 R. Michaels Bizarre pedestal correlation
Jiang asked me about some TDC spectra on H-arm, seeing
double peaks. At first I thought they may be T4, but when I
filtered out T3 only I get spectra in figure 1. There are selftiming
peaks on S1. Normally they only appear on S2. My feeling is
this is due to particles much slower than "protons of 1.936 GeV"
(some background ?) but I haven't proven this.
Another peculiarity noted is that some ADC spectra have unusually
broad and low-valued pedestal (see fig 2). Normally if pedestal
suppression is off, the pedestal is a narrow peak at 300 to 500.
I've seen spectra like this before when a channel had a lot
of positive-going noise (instead of negative-going signal), but
its suspicous that it is seen on both left and right PMT.
FIGURE 1
FIGURE 2
