The AcdPedestal script measure the pedestal by taking random triggers with the HV off.
We keep track of the following values.
Mean: the mean pha value from 100 random triggers
RMS: the rms of the pha values from 100 random triggers
Note that the gains are set such that a MIP is about 400 pha counts above pedestal, and that the
zero-suppression is set to 15 pha counts above pedestal.
The test points here include both "CPT" and "LPT" tests list in the full list of ACD test phases.
Comments:
The output of this test was given in two different formats.
Most of the test phases on had one type of output.
For the first two sets of plots the reference is data taken at GSFC
For the last two sets of plots the reference is data taken at SLAC
The pedestals show quite a bit of temperature dependence. This has been quantified. Link to follow.
The increase in RMS in phases 46 is b/c the HV bias was on in that test by mistake
Plot of values
Comments
Plot of diff W.R.T. reference
Pedestal value
Range 0-1200
RMS of pedestal data
Range: 0 - 6
Pedestal value
Range 0-1200
RMS of pedestal data
Range: 0 - 6
Eric Charles
Last modified: Fri Oct 13 14:57:00 PDT 2006