PMT Background Spectra

PMT 14 was run with a bias voltage of -1100 V with and without scintillator 1-66-? in the darkroom. The connection to the DAQ board was modified with varying attenuators. Each event was self-triggered with a varying trigger threshold for a total of 100k events.

Table 1: Data files used
Run	Scintillator?	Attenuation	Trigger Threshold	Data file
1	yes	none	8280	130911_pmt14_background_8280_1100v_x10.dat
2	yes	10x	8230	130917_pmt14_background_8230_1100v_x10_x10atten_1.dat
3	no	none	8280	130920_pmt14_background_8280_1100v_x10_no-scint.dat

Unattenuated Background Run with Scintillator

Figure 1: Baseline Standard Deviation

The red line at a standard deviation of 6 in Figure 1 is the highest baseline standard deviation allowed in the subsequent plots for the unattenuated background run.

Figure 2: Pulse saturation

The red line in Figure 2 represents the saturation limit of 4500 channels for the pulse amplitude. This pulses used to make this histogram have a baseline standard deviation less than 6.

Figure 3: Pulse maximum amplitude and area

Both histograms in Figure 3 exclude pulses with an amplitude greater than 4500 channels or a baseline standard deviation greater than 6. the histogram of area under the pulse also excludes pulses with a secondary pulse before the main pulse.

10x Attenuated Background Run with Scintillator

Figure 4: Baseline Standard Deviation

The red line at a standard deviation of 6 in Figure 4 is the highest baseline standard deviation allowed in the subsequent plots for the unattenuated background run.

Figure 5: Pulse saturation

The red line in Figure 5 represents the saturation limit of 4500 channels for the pulse amplitude. This pulses used to make this histogram have a baseline standard deviation less than 6.

Figure 6: Pulse maximum amplitude and area

Both histograms in Figure 6 exclude pulses with an amplitude greater than 4500 channels or a baseline standard deviation greater than 6. the histogram of area under the pulse also excludes pulses with a secondary pulse before the main pulse.

Unattenuated Background Run without Scintillator

Figure 7: Baseline Standard Deviation

The red line at a standard deviation of 6 in Figure 7 is the highest baseline standard deviation allowed in the subsequent plots for the unattenuated background run.

Figure 8: Pulse saturation

The red line in Figure 8 represents the saturation limit of 4500 channels for the pulse amplitude. This pulses used to make this histogram have a baseline standard deviation less than 6.

Figure 9: Pulse maximum amplitude and area

Both histograms in Figure 9 exclude pulses with an amplitude greater than 4500 channels or a baseline standard deviation greater than 6. the histogram of area under the pulse also excludes pulses with a secondary pulse before the main pulse.