The Calibration Processors

In this, and the following chapters, a set of calibration processors are described that together handle all aspects of the measurement of Cerenkov photon production:-

• OCA: Optical Calibration deals with photon transport through D$_2$O , H$_2$O and the acrylic vessel and its firing of the PMT. See 28.1

• PCA: PMT Calibration deals with the process within the PMT that converts the light into charge and the timing of the signal produced by the PMT. See 26.1

• ECA: Electronics Calibration deals with the way analogue charge and time signals are digitized. This last calibration is relevant for all channels, including those that are not connected to PMTs. See the remainder of this chapter.

• TRF: Trigger Efficiency calibration deals with the probability that, given $N$ in-time channels firing, the NHIT trigger fires. See 29.1

These calibration processors do not form part of the Monte Carlo and analysis set of processors. For this reason, they disconnected and will not be available by default if the standard installation tools are used. See section 11.6.3 for details about disconnected SUs. However they do produce constants that are applied to the raw data and so effect any results that are obtained from SNO. Consequently they are included in SNOMAN as part of the policy of making essential off-line software available to the full collaboration.