论文部分内容阅读
本文描述 Am-Be 或 Ra-Be 源置于石蜡球内所构成的球形热中子源。石蜡球的直径有21和25厘米两种。分别用 BF_3管和固体径迹探测器(~(235)U-涤纶膜)测定球源的热中子强度,二者在10%以内相符。石蜡球直径为21厘米的 Am-Be 和 Ra-Be 源的热中子强度与源中子强度之比分别为0.15±0.01和0.17±0.01。21厘米球源比25厘米球源的热中子强度约大10%。球源的方向性取决于快中子源的方向性和慢化层厚度的不均匀性,但在垂直于源轴方向上的热中子通量,接近于按各向平均的热中子通量。距源20—300厘米处的热中子通量随距离的变化服从反平方律。还测量了球源附近辐射场的剂量率。
This article describes the spherical thermal neutron source formed by the Am-Be or Ra-Be source placed inside a paraffin ball. The diameter of the wax ball 21 and 25 cm two. The thermal neutron intensity of the ball source was measured with a BF_3 tube and a solid track detector (~ (235) U-Dacron membrane, both within 10%. The ratio of the thermal neutron intensities to the source neutron intensities of the Am-Be and Ra-Be sources with a paraffin wax sphere diameter of 21 cm were 0.15 ± 0.01 and 0.17 ± 0.01.21 cm respectively. The ratio of the thermal neutron About 10% strength. The directivity of a spherical source depends on the directivity of the fast neutron source and the thickness of the moderator layer. However, the thermal neutron flux in the direction perpendicular to the source axis is close to the average thermal neutron flux the amount. The thermal neutron flux at 20-300 cm away from the source obeys the anti-squared law as a function of distance. The dose rate of the radiation field near the ball source was also measured.