LAC, FLE and FHE thresholds

Python script for LAC, FLE, FHE

I wrote a python script to easily run the code (genHists* and fit* and monitoring code) for LAC, FLE, FHE. It also plot threshold distribution if asked.
The script is located here : /a/sulky36/g.glast.u33/sanchez/CALcalib.py

A script only to plot threshold distribution (/a/sulky36/g.glast.u33/sanchez/PlotRun.py)

First look at genTrigMonitorHists and fitTrigMonitorHists

Zach wrote a code to monitor FLE and FHE threshold with nomSciOps runs. We used run 077018082.

PED : digitization-licos-v3r9p3_077014293_digi_DIGI.FLIGHT_GAIN.calPed.txt
MuSlope : digitization-licos-v3r9p3_077014313_digi_DIGI.FLIGHT_GAIN.muSlope.txt

The following figure shows threshold values. We have two populations : low energy should be FLE threshold value and hight energy FHE threshold. For FLE the mean value is around 150 Mev. There is not enough statistic for FHE threshold.

The code works find at SLAC. I have some issues to run it on my laptop sue to version conflict)

A look at the new version of the code with nomSciOps runs.

We used run 077018082.
PED : digitization-licos-v3r9p3_077014293_digi_DIGI.FLIGHT_GAIN.calPed.txt
MuSlope : digitization-licos-v3r9p3_077014313_digi_DIGI.FLIGHT_GAIN.muSlope.txt

Zach made some changes in the code to be less sensitive to the trigger noise. The main change is a better definition of 'firstNonZeroBin' variable. Here is part of his mail.

Basically I have replaced David's 'firstNonZeroBin' variable w/ a 'firstBin>15%max' which should serve the same purpose - it should avoid sensitivity to any noise triggers in the LAC circuit.

Also I have a gemDeltaEventTime < 500 microseconds cut in genLACHists.exe which should also reduce noise hits.

Also I restricted the threshold fit parameter, making it a little more stable.

LAC value distribution for run 077018222. The new code greatly improve the fit. Only few LAC value are obviously not found.

LEX8 signal histograms for 2 channel badly fitted

LEX8 signal histogram for crystal T3L5C8 which was badly fitted with previous version.

Impact on LAC runs, TVAC run 077016907.

There is no major impact. Fitted LAC values remain almost the same.

Conclusions

We are ready to monitor LAC, FLE, FHE threshold.

Finding LAC value with nomSciOps runs

Berrie and I (David Sanchez) had a look at how the code works with nomSciOps runs.
We found that some events have direct diode deposit on the opposite face. This case is not yet taking into account in the code that generated LAC histogram leading to bad LAC value.

This plot is the LAC value distribution for run 077018222. X axis is p0-Ped . We used the following configurations files:

PED : digitization-licos-v3r9p3_077014293_digi_DIGI.FLIGHT_GAIN.calPed.txt
MuSlope : digitization-licos-v3r9p3_077014313_digi_DIGI.FLIGHT_GAIN.muSlope.txt

All files can be found at /afs/slac.stanford.edu/g/glast/ground/releases/calibrations/CAL/LAT-flight_gain/

This is the LEX8 signal histogram for tower 9, layer 4, crystal 0 Face 1. X axis is ADC value . This crystal is one with weird LAC value. This is due to non-empty low energy bin. In fact the fitting procedure use the first non-empty bin as a reference. In such case, this first bin is not relevant. To tackle this issue we have modify the code that generate LAC histograms to cut the events with direct diode deposit.

the following plot are LAC value distribution and LEX8 signal histograms for the same run and crystal

It remains no bad value. It is probably useful to modify all scripts generating LAC, FLE, FHE histograms to take this case into account.