An in-situ analysis and measurement of thorium-234, uranium isotopes in seawater

作者：Zeng Xianzhang^*; Qiu Manhua; Yin Mingduan; Zeng Wenyi; He Jianhua; Wan Xueguo; Chen Hengliang; Li Jing; Tan Baozeng

来源：Acta Oceanologica Sinica, 2007, 26(3): 73-83.

• ocean
• beta counting-alpha spectrum apparatus
• radiochemical separating
• thorium-234
• uranium-238

A low-level beta counting-alpha spectrum. apparatus used for the detection of the beta radiation of thorium-234 and alpha spectrum of thorium-228 simultaneously and an easy operating procedure for the enrichment, radiochemical. separating, sampling and measurement of thorium-234 and uranium-238 in the ocean are developed based on the requirements of analyzing export productivity in the euphotic zone via thorium-234 - uranium-238 radioactivity disequilibrium. The detecting efficiency both of P and alpha radiation is higher than 20%. The background of beta radiation is less than 0.5 min(-1), and the energy resolution of alpha detector is better than 1%. Total recycle ratio of thorium-234 is about 75%. Using the above apparatus and procedure, the radioactivities of dissolved thorium-234 and uranium-238, particle thorium-234 and uranium-238 in seawater of the South China Sea, the Southern Ocean and the Arctic Ocean were analyzed.

• 出版日期2007
• 单位国家海洋局第三海洋研究所