不同排源方式对辐照剂量不均匀度及射线利用率的影响

Influence of Difference Irradiation Source Arranging Styles on the u Value and Rays Utilization Rate

利用5.84×1015Bq60Co放射源研究了放射源单层排列与3层排列对剂量不均匀度及射线利用率的影响。放射源单层排列时,垂直方向剂量分布不均匀度为5.32,复方甘草片产品箱内剂量不均匀度为1.46,需进行人工换层操作,射线利用率达28.4%。放射源3层排列时,垂直方向剂量不均匀度为1.15,复方甘草片产品箱内剂量不均匀度为1.48,射线利用率达29.0%。两种排源方式的射线利用率相差0.6个百分点,差异不明显,但3层排源较单层排源省时省力,产品辐照质量更有保障。

Using 5.84×1015 Bq 60Co radiation source, the influence of different radiation source arranging styles, single-layer and 3-layers on the u value and rays utilization rate were studied. When irradiation sources were arranged in single layer, the u value of dose distribution on the vertical direction reached 5.32, while in the compound liquorice tablets box was 1.46 as artificial replacement operation was needed, the rays utilization rate was 28.4%. When irradiation sources were arranged in 3 layers, the u value of dose distribution on the vertical direction was 1.15, and in the compound liquorice tablets box was 1.48, the utilization rate of radioactive rays reached to 29.0%. The difference of ray utilization ratio was 0.6 percentage points between two arranging styles, not significantly difference. However, the 3-layers arrangement saved time and labor, as well as improved the radiation quality of goods also than single-layer arrangement.