Aydarous A Sh
Physics Department, Taif University, Al-Hawiah, Taif, PO Box 888, Kingdom of Saudi Arabia.
Radiat Prot Dosimetry. 2008;130(2):141-8. doi: 10.1093/rpd/ncm494. Epub 2008 Jan 25.
The size of hot particles contained in nuclear fallout ranges from 10 nm to 20 microm for the worldwide weapons fallout. Hot particles from nuclear power reactors can be significantly bigger (100 microm to several millimetres). Electron backscattering from such particles is a prominent secondary effect in beta dosimetry for radiological protection purposes, such as skin dosimetry. In this study, the effect of electron backscattering due to hot particles contamination on skin dose is investigated. These include parameters such as detector area, source radius, source energy, scattering material and source density. The Monte-Carlo Neutron Particle code (MCNP4C) was used to calculate the depth dose distribution for 10 different beta sources and various materials. The backscattering dose factors (BSDF) were then calculated. A significant dependence is shown for the BSDF magnitude upon detector area, source radius and scatterers. It is clearly shown that the BSDF increases with increasing detector area. For high Z scatterers, the BSDF can reach as high as 40 and 100% for sources with radii 0.1 and 0.0001 cm, respectively. The variation of BSDF with source radius, source energy and source density is discussed.
全球核武器爆炸产生的放射性沉降物中所含热粒子的尺寸范围为10纳米至20微米。来自核动力反应堆的热粒子可能大得多（100微米至几毫米）。对于诸如皮肤剂量测定等放射防护目的的β剂量测定，此类粒子的电子背散射是一个显著的次级效应。在本研究中，研究了热粒子污染引起的电子背散射对皮肤剂量的影响。这些参数包括探测器面积、源半径、源能量、散射材料和源密度。使用蒙特卡罗中子粒子代码（MCNP4C）计算了10种不同β源和各种材料的深度剂量分布。然后计算了背散射剂量因子（BSDF）。结果表明，BSDF大小对探测器面积、源半径和散射体有显著依赖性。结果清楚地表明，BSDF随探测器面积的增加而增加。对于高Z值散射体，对于半径分别为0.1厘米和0.0001厘米的源，BSDF可分别高达40%和100%。讨论了BSDF随源半径、源能量和源密度的变化。
