Overview

One of the first stages of calibration will involve the use of the laserball source to provide information needed to extract various parameters which describe the ``optical'' properties of the detector. These parameters include the relative efficiency of each PMT as a function of wavelength, and the absorption/scattering coefficients as a function of wavelength for individual acrylic tiles as well as for heavy and light water. The first step of this process is the acquisition of histograms of the relative arrival times recorded in each PMT with respect to the calibration trigger for $10^5$ or more laserball pulses fired at the single-photoelectron level. This will be done for $\sim$5 different wavelengths at a variety of laserball positions within the detector. These histograms may either be generated in ``hardware,'' or after passing through usual acquisition routes in software. For the time being, it will be assumed that these files are stored in normal HBOOK format whatever way they're initially created. Simulated calibration histograms can be created using RUN_LASERBALL.CMD with SNOMAN. The next step involves the processing and reduction of these histograms into optical parameter values. This is the function of the set of routines described here as part of the OCA software unit.