Performance of parallel plate ionization chamber for medical irradiation

Current-voltage characteristic of parallel-plane ionization chamber with inhomogeneous ionization

“…These data should be with a great precision in the whole range of conditions. Therefore the reference [6] was noticed in which the creation of a parallel-plane ionization chamber (with cm 3 . 0 d = ), allocated for medical irradiations, is reported.…”

“…, as for each series the measurement are done for at least 15 magnitudes of voltages applied to the chamber. Especially useful for the measurements precision in [6] is turned out the application of the current cont i of another ionization chamber for the control of beam intensity and for the correction of the obtained results according this current. In this case the control ionization chamber is working in a regime of saturation and neither the gas pressure nor the applied voltage to it is changing.…”

“…Here we will use only the results from the series with a change in the working pressure of the gas in the chamber at one and the same intensity of ions beam. For these series the dependence between the relative effectiveness cont i / i f = of the investigated ionization chamber in comparison with the control one and the applied voltage U is represented graphically in [6].…”

Analytical form of current-voltage characteristic of parallel-plane, cylindrical and spherical ionization chambers with homogeneous ionization

“…These data should be with a great precision in the whole range of conditions. Therefore the reference [7] was noticed in which the creation of a parallel-plane ionization chamber (with Here we will use only the results from the series with a change in the working pressure of the gas in the chamber at one and the same intensity of ions beam. For these series the dependence between the relative effectiveness cont i / i f = of the investigated ionization chamber in comparison with the control one and the applied voltage U is represented graphically in [7].…”

“…We suppose that at a constant intensity of the ionizing irradiation Using (37), (38) and the data represented in table 2 the data from [7] are shown in figure 4. As it is evident from figure 4, in the investigated range of values of the electric field strength, the theoretical curve moves either close or between the experimental results.…”