Photon energy responses of some ionization chambers with different sizes and materials

It is important for us to be able to calculate the photon energy responses of ionization chambers prior to manufacturing them. But the energy response derived from general cavity theory (BRAGG-GRAY formula) cannot be applied to the case of ionization chambers with large cavity size or filled with highly pressurized gas. In this paper, first we calculated the energy responses of such ionization chambers by using BURLIN's formula which took account of the generation and absorption of secondary electrons in the cavity gas, and compared these results with our experimental data. Secondly, the calculations of energy response were performed in the case of double wall ionization chambers based on BURLIN's theory. These calculated results have a good agreement with the experimental ones in each case. So it can be concluded that BURLIN's theory is well applicable to the large size or double wall ionization chambers. (author)