A Cylindrical High-Pressure Xenon Chamber with Shielding Mesh

HPXe ionization chamber is considered as an ideal detector for the Radiation Monitoring System in nuclear power plants, as detector response has been shown to be uniform over large temperature ranges up to 170 degrees C. By using the MCNPX simulation code, the energy spectra was calculated with respect to the thickness of the outer shell and the dependence on the incident direction of the radiation sources in the nuclear power plant. A cylindrical HPXe ionization chamber, which was configured with a shielding mesh to improve its energy resolution, was designed and fabricated. With the gas purification and injection system, Xe and 7% He-4 was purified and injected in the chamber and the performances of the chamber were evaluated. The leakage currents and saturation currents of the chamber were measured with an electrometer, respectively. Linearity against dose rates was also measured with Ra-226 (0.906 mCi) radiation source and the 0.994 of root-mean-square value was estimated. The stability test was performed with the system for 10 hours and its results are presented. In a future work, energy spectra with the manufactured HPXe ionization chamber will be measured and compared with the simulated energy spectra.