University of Wisconsin-Madison

First Year Performance Paper - Section 3

3 Calibration of gains and timing

Ratio of ATWD channel 0 (high-gain) waveform area to ATWD channel 1 moderate-gain) waveform area for 3000 LED pulses.
Ratio of ATWD channel 0 (high-gain) waveform area to ATWD channel 1 moderate-gain) waveform area for 3000 LED pulses.

Several steps are necessary to transform the DOM readouts to waveforms in physical units of charge and time. Section 3.1 describes the DOM specific calibration of the ATWD sampling frequency and voltage scale and the measurement of the different gains of the three ATWD channels. Section 3.2 will describe the PMT gain calculation. The entire procedure is carried out by DOM-Cal, a software package executed on the embedded DOM CPU. In section 3.3 the time calibration between the different DOMs and an absolute reference time are described. Section 3.4 describes calibration with flashers, and in section 3.5 we discuss the calibrated waveforms measured by a DOM.