Application of coincidence Doppler broadening spectroscopy to some liquids and gamma-irradiated polymers
作者单位：Radiation Science CenterHigh Energy Accelerator Research Organization(KEK)1-1 OhoTsukubaIbaraki 305-0801Japan
会议名称：《第九届全国正电子谱学会议》
会议日期：2005年
学科分类：07[理学] 070202[理学-粒子物理与原子核物理] 0702[理学-物理学]
摘 要：Recently, a new positron annihilation technique, coincidence Doppler broadening (CDB) spectroscopy, has appeared as a chemical probe in positron spectroscopy. Compared with the traditional Doppler broadening measurement using a single Ge detector, the combined use of two Ge detectors improves the energy resolution of thewhole system by a factor of (?);meanwhile, the peak-to-background ratio of the measured CDB spectra is significantly improved from -200 to 106. This enables one to identify positron annihilation with high momentum electrons belonging to certain element like oxygen. Based on this principle, we successfully investigated the effect