Signal cable timing

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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* [math]\Delta t[/math] 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