A measurement system for alpha and beta surface emission rate using MWPC

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(Tl-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 E n values of all measured sources are within ±1.更多还原