A study on characteristics of a large-area parallel plate ionization chamber for radiotherapeutic dosimetry

This study developed a large-area parallel-plate ionization chamber with an effective sensitive area diameter of 16 cm, aimed at accurately measuring the depth dose of proton beams. The dataset includes test results of key parameters such as leakage current, saturation characteristics, repeatability, dose linearity, and energy response of the parallel-plate ionization chamber. The testing environment included photon radiation fields and medical proton beams.Figure 1 illustrates the structure of the ionization chamber, and Figure 2 shows the test schematic. In this study, an electrometer independently designed and developed by the research group was used to collect and quantitatively analyze the ionization charge generated in the large-area parallel-plate ionization chamber. Figure 3 demonstrates the linear response of the electrometer.Figures 4 to 9 present the performance test results of the parallel-plate ionization chamber.