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一、引言在核素活度计量学中,被测对象都需制成适当形式的放射源。放射源的制备十分重要,它直接影响测量的结果。源的制备方法很多,能谱测量用源因不需定量,所以有许多有效的方法。定量源的制备方法也很多,但因有的方法需要较复杂的设备,故不易为一般实验室所采用。本文介绍“蒸发法”制备定量源以及β标准立体角活度测量方法中源的制备。二、源衬托物——薄膜的制备 1.薄膜的选择对薄膜的要求是:(1)材料的原子序数应尽量小,以减小散射与吸收;(2)膜要薄而均匀,使膜吸收尽量小;(3)耐热、耐化学腐蚀;(4)能保持长时间稳定;(5)具有一定的机械强度;(6)具有导电性(β标准
I. INTRODUCTION In nuclide activity metrology, the test object needs to be made into an appropriate form of radioactive source. Preparation of radioactive sources is very important, it directly affects the measurement results. There are many ways to prepare a source. There are many effective methods for measuring the source of energy spectrum because it does not require quantification. There are many methods to prepare the quantitative source, but some methods require more complex equipment, so it is not easy to use for the general laboratory. This article describes the “evaporation” preparation of quantitative sources and β standard solid angle activity measurement source preparation. Second, the source backing - the preparation of the film 1. The choice of film The film requirements are: (1) the atomic number of the material should be as small as possible to reduce the scattering and absorption; (2) the film should be thin and uniform, so that the membrane Absorption as small as possible; (3) heat resistance, chemical resistance; (4) can maintain a long time stability; (5) has a certain mechanical strength; (6)