Design and construction of the first prototype ionization chamber for CSNS and Proton Accelerator （PA） beam loss monitor （BLM） system is reported. The low leakage current （〈0.1 pA）, good plateau （≈800 V） and...Design and construction of the first prototype ionization chamber for CSNS and Proton Accelerator （PA） beam loss monitor （BLM） system is reported. The low leakage current （〈0.1 pA）, good plateau （≈800 V） and linearity range up to 200 Roentgen/h are obtained in the first prototype. All of these give us good experience for further improving the ionization chamber construction.展开更多
We have developed a large area multi-wire proportional counter （MWPC） as a standard for the measurement of alpha and beta surface emission rate at the Shanghai Institute of Measurement and Testing Technology （SIMT...We have developed a large area multi-wire proportional counter （MWPC） as a standard for the measurement of alpha and beta surface emission rate at the Shanghai Institute of Measurement and Testing Technology （SIMT）. To shorten the preparation time for chamber gas refilling, a self-designed gas control unit was adopted. Various characteristics of the system have been studied. The uncertainties were analysed. Three certified alpha plane sources （Am-241） and six certified beta plane sources （T1-204 and Sr-90/Y-90） were measured by this system, The results show excellent agreement with the surface emission rate reported by the National Institute of Measuring, China （NIM） that En values of all measured sources are within ±1.展开更多
Based on the first ionization chamber （IC） prototype, the structure, working gas component and electrode material of the IC are improved. The test of the improved IC shows that the plateau length is about 2000 V, th...Based on the first ionization chamber （IC） prototype, the structure, working gas component and electrode material of the IC are improved. The test of the improved IC shows that the plateau length is about 2000 V, the plateau slope is less than 0.2%/100 V, the sensitivity is 19.6 pA/rad·h 1, the up-limitation of the linearity can be up to 3.6×105 rad/h, and the applied voltage can be operated to 3500 V. The test results show that the performance of the improved IC meets the requirements of the beam loss monitor.展开更多
A boron-lined proportional counter （BLPC） with a count rate limit close to the multi-wire proportional counter was manufactured to measure the mixed field around reactors. After measurement with a standard Am-Be neu...A boron-lined proportional counter （BLPC） with a count rate limit close to the multi-wire proportional counter was manufactured to measure the mixed field around reactors. After measurement with a standard Am-Be neutron source （activity： 100 mCi）, the results show that the operating voltage of the BLPC is 800 V, the plateau length is 100 V and the slope is 13.2%/100 V. The width and rise time of the output pulse of the BLPC are 1.26 μs and 370 ns, respectively. When the BLPC works at a count rate of 1.0 × 10 5 count/s, the pulse pile-up probability of the BLPC is 3.6%. A clear peak can be seen in the pulse height spectrum of the BLPC. and the performances illustrate that a BLPC working in pulse mode can serve as a source range detector of reactors.展开更多
文摘Design and construction of the first prototype ionization chamber for CSNS and Proton Accelerator （PA） beam loss monitor （BLM） system is reported. The low leakage current （〈0.1 pA）, good plateau （≈800 V） and linearity range up to 200 Roentgen/h are obtained in the first prototype. All of these give us good experience for further improving the ionization chamber construction.
基金Supported by National Natural Science Foundation of China(41204133)
文摘We have developed a large area multi-wire proportional counter （MWPC） as a standard for the measurement of alpha and beta surface emission rate at the Shanghai Institute of Measurement and Testing Technology （SIMT）. To shorten the preparation time for chamber gas refilling, a self-designed gas control unit was adopted. Various characteristics of the system have been studied. The uncertainties were analysed. Three certified alpha plane sources （Am-241） and six certified beta plane sources （T1-204 and Sr-90/Y-90） were measured by this system, The results show excellent agreement with the surface emission rate reported by the National Institute of Measuring, China （NIM） that En values of all measured sources are within ±1.
文摘Based on the first ionization chamber （IC） prototype, the structure, working gas component and electrode material of the IC are improved. The test of the improved IC shows that the plateau length is about 2000 V, the plateau slope is less than 0.2%/100 V, the sensitivity is 19.6 pA/rad·h 1, the up-limitation of the linearity can be up to 3.6×105 rad/h, and the applied voltage can be operated to 3500 V. The test results show that the performance of the improved IC meets the requirements of the beam loss monitor.
文摘A boron-lined proportional counter （BLPC） with a count rate limit close to the multi-wire proportional counter was manufactured to measure the mixed field around reactors. After measurement with a standard Am-Be neutron source （activity： 100 mCi）, the results show that the operating voltage of the BLPC is 800 V, the plateau length is 100 V and the slope is 13.2%/100 V. The width and rise time of the output pulse of the BLPC are 1.26 μs and 370 ns, respectively. When the BLPC works at a count rate of 1.0 × 10 5 count/s, the pulse pile-up probability of the BLPC is 3.6%. A clear peak can be seen in the pulse height spectrum of the BLPC. and the performances illustrate that a BLPC working in pulse mode can serve as a source range detector of reactors.
