# Checking the FCAL gains

Goal makes a list of all bad and/or suspicious channels. The monitoring is to be repeated each time the FCAL energy calibration is changed.

The macro can be found here: https://halldweb.jlab.org/primexd/he-phase2/

1/ Period 4 to 28 should be checked

2/ For each period:

a/ Look at the report: be_phase2_method0_period_[4-8].pdf & he_phase2_method0_period_[14-21].pdf
b/ There are two ways to check for the bad and/or suspicious channels.
* Look at the individual diphoton invariant mass for each blocks, a clear pi0 resonance should be observed for all blocks except for blocks belonging to the two outer rings of FCAL:  checking_be_phase2_method0_period_[4-8].py & checking_he_phase2_method0_period_[14-21].py
* Use check_fcal.c to look at the histogram root file runpi0.root for each period


3/ Check for the block listed as bad and/or suspicious, the diphoton invariant mass, and time difference distributions to see if it is a possible calibration issue (energy and/or time). To do so use check_block.c

HOW-TO use check_fcal.c: root -l runpi0.root 'check_fcal.c(argument1, argument2, argument3)' argument1 is a string that can be empty, "", or corresponds to an ASCII file containing only one column argument2 is an integer that can range from 0 to 5

- 0 hit pattern for all central block cluster energy
- 1 hit pattern for all central block cluster energy above 1 GeV
- 2 hit pattern for all central block cluster energy above 2 GeV
- etc ...


argument3 is an integer that ranges from 1 to 3

- 1 to draw a square and write the block number for each block
- 2 to draw a square and write the block number for each block which is 3\sigma outside the optimal gain value (1.05)
- 3 to draw a square and write the block number for the block listed in the ASCII file mentioned above


HOW-TO use check_block.c: root -l runpi0.root 'check_block.c(argument)' argument is a string that corresponds to an ASCII file containing only one column