ABSTRACT
Given an x-ray beam, the dosimetry goal is to determine the absorbed dose at some specific point in a medium under so-called reference conditions using a calibrated suitable detector, usually an ionization chamber. The process is known as beam calibration and establishes the reference dosimetry against which any other condition refers to, or any other detector type can be cross-calibrated. Ionization measurements require a number of corrections, coefficients and factors to convert the detector reading into absorbed dose that depend strongly on the x-ray beam spectra. This chapter describes the beam calibration dosimetry equations, termed the dosimetry formalism, and the computation of the most relevant coefficients and factors. The basic quantities and concepts on the dosimetry of kilovoltage x rays are presented earlier, in Chapter 4.
