Studies of Cavity Ionization Chambers with Megavoltage X-rays

Abstract

The paper describes the work undertaken and the experimental equipment used in an extensive programme on many kinds of cavity ionization chambers used with 4, 6, 8 and 15 MeV linear accelerators. The analytical studies reported refer only to graphite chambers. Functions have been derived applicable to photon energies in the range 0·03 MeV to 15 MeV, whereby the broad beam attenuation and state of particle equilibrium may be determined for graphite cavity chambers having a wide range of wall thicknesses. The relevance of the new data to various studies of immediate interest is examined.