−Table of Contents
Cf-252 Measurements (write-up of work from 20170701 to 20170716
External trigger
Baseline subtraction issues
Issues were encountered with subtracting a constant baseline when the TB4 board was externally triggered. Two different methods were explored to improve this baseline subtraction. First, a constant baseline was subtracted. Then, Landau and Gaussian functions were fit to a histogram of the revised pulse amplitudes to determine a correction factor, which was then subtracted from the waveform.
| Figure: Waveforms for long window, external trigger of TB4 SiPMs, Event 70 | ||
|---|---|---|
| Fit Type | Fit Histogram | Waveform |
| Channel 0 | ||
| Landau |  |  |
| Gauss |  |  |
| Channel 1 | ||
| Landau |  |  |
| Gauss |  |  |
| Channel 2 | ||
| Landau |  |  |
| Gauss |  |  |
| Figure: Waveforms for long window, external trigger of TB4 SiPMs, Event 9070 | ||
|---|---|---|
| Fit Type | Fit Histogram | Waveform |
| Channel 0 | ||
| Landau |  |  |
| Gauss |  |  |
| Channel 1 | ||
| Landau |  |  |
| Gauss |  |  |
| Channel 2 | ||
| Landau |  |  |
| Gauss |  |  |
| Figure: Waveforms for long window, external trigger of TB4 SiPMs, Event 17070 | ||
|---|---|---|
| Fit Type | Fit Histogram | Waveform |
| Channel 0 | ||
| Landau |  |  |
| Gauss |  |  |
| Channel 1 | ||
| Landau |  |  |
| Gauss |  |  |
| Channel 2 | ||
| Landau |  |  |
| Gauss |  |  |
Histograms of Dark Count Amplitudes and Areas for External Trigger
| Figure: Histograms of Dark Count Amplitudes and Areas for External Trigger | |
|---|---|
| Amplitude | Area |
 |  |
 |  |
 |  |
No difference in dark counts between “Shield” and “Gd Vial” runs.
SiPM trigger: only one channel
Baseline subtraction method: average over first 30 bins and subtract from pulse
SiPM trigger: coincidence between channels 0 and 1
Baseline subtraction method: average over first 30 bins and subtract from pulse