【摘要】 描述了１台用于核设施、核材料现场测量的可移动式高分辨分段γ扫描装置。本装置用７５Ｓｅ和１６９Ｙｂ作为透射源测量样品对γ射线的透射率，采用近立体角三维自吸收校正模型计算样品自吸收校正系数ＣＦ（ＡＴ），较准确计算出样品对γ射线的自吸收校正量。本装置适合于准确测定中低密度非均匀核返料和核废物中核材料含量或裂变产物的含量，对２３５Ｕ硝酸铀酰均匀介质的盲样，测量结果与控制电位库仑测定的标准值之偏差小于１．４％。更多还原

【Abstract】 A transportable segmented gamma ray scanning system(TSGS) for measuring on site has been developed for the purposes of the accounting for and control of nuclear material in plant. The system developed is used for nondestructive assay of the contents of 235 U, 239 Pu or fission products existing in a great quantity of low density or median density heterogeneous residual, scraps or wastes. The system developed is transportable and highly automated. It is provided with the function of correcting sample’s self attenuation in gamma ray nondestructive assay. The system developed consists of a transmission source, a rotatable scanning plate, a beam shutter, and shielding body, stepping motors and control system, HPGe detector, nuclear electronics and computer. The full scale segmenting and scanning of samples, spectrum data acquiring and processing could be fulfilled automatically. The system was calibrated using five standard samples of uranyl nitrate (90 % 235 U). The uncertainty of calibration is ±1 %. A homogeneous sample prepared spceially was used for testing this system. The measurement results for this homogeneous sample were compared with the measurement standard value of controlled potential coulometer(CPC). Bias of both results is about 1 4 %.更多还原