锶-90同位素放射源屏蔽结构设计

在~(90)Sr放射源结构设计基础上,利用Monte Carlo程序MCNPX计算~(90)SrTiO_3陶瓷源表面的轫致辐射能谱和放射源外空间的剂量当量分布情况,并计算和设计屏蔽层。结果表明,90SrTiO_3陶瓷放射源表面的平均光子通量率约1.2×10~(10)cm~(-2)·s~(-1),表面最小剂量当量率约20Sv/h;应用厚度为7cm的钨材料屏蔽后,表面和1m处最大剂量当量率分别约为1.35mSv/h和0.027mSv/h,满足放射源运输要求。

Shielding Structure Design of 90 Sr Isotope Radiation Source

The bremsstrahlung spectrum on the surface of a 90SrTiO3 ceramic radiation source was computed by using MCNPX on the base of the designed structure of the 90 Sr radioactive source .The distribution of the dose equivalent was calculated and analyzed . The results showed that the average photon flux was 1.2 × 1010 cm -2 · s-1 on the surface of the radiation source ,and the minimum dose equivalent rate of the surface was 20 Sv/h .By using 7 cm tungsten as the shielding structure ,the maximum dose equiva-lent was 1.35 mSv/h on the surface and 0.027 mSv/h at 1 m below the surface .So the shielding material and structure designed meet the limit of radiation dose equivalent dur-ing the transportation .