DOM-Cal Calibration Software

Overview

DOM-Cal is a set of software designed to calibrate the IceCube DOMs, and is written / maintained by myself and Jim Braun. It is originally based on the Python DOM calibration software written by Kael Hanson.

DOM-Cal has several components:

• The DOM-resident calibration software, written in C and compiled for the DOM's ARM processor. This portion performs all calibration routines and runs in parallel on the DOMs.
  
• The surface client, written in Java, which communicates with the DOM-resisdent software, collects the results, and writes them to output files (in XML format).
  
• The Calibrator.java module, which allows access to calibration results for analysis.

The software is available in the dom-cal project on glacier.

Functionality

The calibration functions which DOM-Cal performs include:

• Calibrating the front-end electronics, including:
  • front-end pulser or discriminator
  • ATWD gain and pedestal pattern
  • ATWD channel amplifier gains
  • ATWD sampling frequency (quadratic fit)
  • FADC gain
  • FADC time offset from ATWD
  • ATWD chip A time offset from ATWD chip B
• Calibrating the PMT gain (log-log gain vs. HV fit)
• Calibrating the transit time (transit time vs. 1/sqrt(HV) fit)
• Measuring residual baselines with testDAQ ("stf") and domapp FPGAs

Documentation

Documentation of the Calibrator.java module is available here. Detailed documentation of the XML result file is available in docushare.

I have also given a number of talks describing DOM-Cal features and calibration methods — please see my presentations page for what's available.

Support Scripts

• get_disc_settings.pl (v1.1) — determine HV and discriminator settings given a target gain and discriminator level in NPE
• get_freq_settings.pl (v1.0) — determine DAC0/DAC4 ATWD trigger bias settings given a target sampling speed in MHz

Sample Output

• Sample XML result file (version 7.4.0— most recent released format)
• Sample string 21 HV / gain plots (11/2005)

DOM-Cal Studies

• Preliminary string 21 transit time measurements (11/2005, 62 DOMs calibrated)
• Comparison of calculated gains at 5E4, 5E6, and 1E7 for multiple DOM-Cal runs (2006, 592 DOMs calibrated)
• IceTop Gain Precision (8/2006, 64 DOMs calibrated with 3 back-to-back runs)
• Baseline shift investigations
• 3/20/2007 IceTop DAQ baseline test runs (4MB tarball, XMLs in new 7.0.0 format)
• 3/30/2007 String 29 DAQ baseline test runs (2.5MB tarball)
• Data mining of DOM-Cal runs on IC-22 + IceTop
• Checks of the discriminator calibration for SPE-level pulses