Signal cable timing
Procedure and setup
PMT timing relative to D30T001 is measured by splitting a pulse from a pulse generator.
PMT top-bottom difference is the mean time difference of the 2 PMT's using the TDC spectrum of a coincidence run with the CF-252 source. The source was placed in the center of all detectors and 150.5 cm above the floor. The trigger detector was located 5.5 cm below the very bottom of the source.
Detector PMT thresholds at 50 mv.
Trigger PMT threshold at 35 mv.
All high voltages are set to -1700 V
Results
| Detector | PMT | sig. cable | Variable index* | relative to D30T001 [ns] | bottom - top [ns] | Run # | Run time [sec] | |
|---|---|---|---|---|---|---|---|---|
| angle | color
| |||||||
| 30 | Red | Top | D30T001 | 1 | +0 (by definition) | +12.5 | r5218 | 1221 |
| Bot | D30B002 | 2 | +12.5 | |||||
| 90 | Yellow | Top | D90T003 | 3 | +1 | +10.5 | ||
| Bot | D90B004 | 4 | +11.5 | |||||
| 150 | Blue | Top | D150T005 | 1 | +1 | +13 | r5217 | 1106 |
| Bot | D150B006 | 2 | +14 | |||||
| 225 | Wood | Top | D225T007 | 3 | -3 | +23 | ||
| Bot | D225B008 | 4 | +20 | |||||
* for ROOT, e.g. evt.TDC1190[1][i], where i is the variable index.
Trigger plugged into patch panel 223A15 : -8 ns