Calibration of Beam Intensity Monitors :

This HOWTO is written as a part of preparation for the 01036 experiment.
Beam intensity monitors are calibrated to Faraday Cup reading (FC).
FC is read using one of the NCS tools (Chart recorder) over a time period of approximately 30 seconds.
Read in beam currents are averaged and compared to scaler readings from beam intensity monitors.

So far we have total 4 NaI(Tl) crystals mounted onto the Target Box (charged particle counters, because the bias voltage of 300V, called TA_SUMNaI ) and two gamma monitors sitting in the corner underneath the Target Box (BaF called TA_BaF and NaI called TA_NaI ).

Procedures to perform calibration:

  1. Open ‘Chart Recorder 32' from NCS folder. There is a shortcut on the desktop of u1pc1 win2000 machine:

 

  1. In the Chart Recorder open pre-existing configuration from “C:\01036\faraday cup001” or just simply write “Z001-FC” into the leftmost window.
  2. Set your beam current (either using attenuators or asking operators to change beam intensity) you want to use as a calibration point.
  3. Insert FC (Z001-FC the one before the target) into the beam and after cca. 30s write the FC data to file (.txt) by calling “Write Trace Data to File…” (see Figure on the following page).
  4. Retract the FC (Z001-FC) and start a new run. After cca. 1-2 min. stop the run and repeat steps 3-5 with a different primary beam intensity.

It is important to develop systematic naming convention for *.txt files with faraday cup reading and run numbers. (The best way is to call them the same: e.g. run1234-4096.evt and 1234.txt for the faraday cup reading)