IONISATION CHAMBER USABLE AS SECONDARY STANDARD FOR MEASURING THE ENERGY DOSE OF X- AND GAMMA RADIATION

摘要

An ionization chamber for measuring an energy dose having a chamber wall with an electromagnetic radiation absorption characteristic equivalent to air, tissue or water and a neck part and being closed on all sides, an air compensation orifice; an outer electrode formed by a conductive coating on the inner surface of the chamber wall, an inner electrode and an electrically conductive ring surrounding the neck part of the chamber wall is disclosed. The chamber wall consists of at least 85% by weight of a base material containing polyacetal in a mixture with up to 20% by weight of polytetrafluoroethylene having additives consisting of one or more of calcium oxide, aluminum oxide, aluminum and carbon. The conductive coating on the inner surface of the chamber wall consists of a material containing one or more elements having an atomic number greater than 8.