Calibration Summary

1. Fine time

Three calibration methods were tested.

Common linear calibration:

all channels use the same fine-bin to time transformation: time[i] -= (Hits_nFineTime[i]-31)*0.0102

Differential linear calibration:

for each channel the range of fine bin distribution is used: time[i] -= 5*(Hits_nFineTime[i]-min)/(max-min)

Variation of min and max values:

Using integration:

time[i] -=5*(integral[i]/total)


calibration stays constant with time (see e. g. here.)

=> First method produces double peaks and gives bad resolution (>60ps with trb_calib runs ).

=> The last method is better than second (15 ps vs. 20 ps mean resolution). The picture shows time resolution of trb runs for second(blue) and third method(red) method. For more see here

Example of fit:

2. TOT offsets

Correlation between mean and LE front:

3. TOT walk correction

Examples: before and after

Resolution for picoquant15173222549.hld.root:

4. LE offsets

Correlation between mean and LE front:

5. Event time offset

Distribution of event offsets for different runs: