Veinot K G, Hertel N E
Y-12 National Security Complex, PO Box 2009, MS 8105, Oak Ridge, TN 37831-8105, USA.
Radiat Prot Dosimetry. 2011 Apr;145(1):28-35. doi: 10.1093/rpd/ncq380. Epub 2010 Dec 8.
The personal dose equivalent, H(p)(d), is the quantity recommended by the International Commission on Radiation Units and Measurements (ICRU) to be used as an approximation of the protection quantity effective dose when performing personal dosemeter calibrations. The personal dose equivalent can be defined for any location and depth within the body. Typically, the location of interest is the trunk, where personal dosemeters are usually worn, and in this instance a suitable approximation is a 30 × 30 × 15 cm(3) slab-type phantom. For this condition, the personal dose equivalent is denoted as H(p,slab)(d) and the depths, d, are taken to be 0.007 cm for non-penetrating and 1 cm for penetrating radiation. In operational radiation protection a third depth, 0.3 cm, is used to approximate the dose to the lens of the eye. A number of conversion coefficients for photons are available for incident energies up to several megaelectronvolts, however, data to higher energies are limited. In this work, conversion coefficients up to 1 GeV have been calculated for H(p,slab)(10) and H(p,slab)(3) both by using the kerma approximation and tracking secondary charged particles. For H(p)(0.07), the conversion coefficients were calculated, but only to 10 MeV due to computational limitations. Additionally, conversions from air kerma to H(p,slab)(d) have been determined and are reported. The conversion coefficients were determined for discrete incident energies, but analytical fits of the coefficients over the energy range are provided. Since the inclusion of air can influence the production of secondary charged particles incident on the face of the phantom, conversion coefficients have been determined both in vacuo and with the source and slab immersed within a sphere in air. The conversion coefficients for the personal dose equivalent are compared with the appropriate protection quantity, calculated according to the recommendations of the latest International Commission on Radiological Protection (ICRP) guidance.
个人剂量当量H(p)(d)是国际辐射单位与测量委员会（ICRU）推荐的一个量，用于在进行个人剂量计校准时近似防护量有效剂量。个人剂量当量可针对体内任何位置和深度进行定义。通常，感兴趣的位置是躯干，个人剂量计通常佩戴于此，在这种情况下，一个合适的近似是一个30×30×15 cm³的平板型体模。对于这种情况，个人剂量当量表示为H(p,slab)(d)，对于非穿透辐射，深度d取0.007 cm，对于穿透辐射，深度d取1 cm。在职业辐射防护中，第三个深度0.3 cm用于近似眼部晶状体的剂量。对于高达几兆电子伏特的入射能量，有许多光子的转换系数可用，然而，更高能量的数据有限。在这项工作中，通过使用比释动能近似和跟踪次级带电粒子，计算了高达1 GeV的H(p,slab)(10)和H(p,slab)(3)的转换系数。对于H(p)(0.07)，由于计算限制，转换系数仅计算到10 MeV。此外，还确定并报告了从空气比释动能到H(p,slab)(d)的转换。转换系数是针对离散的入射能量确定的，但提供了系数在能量范围内的解析拟合。由于空气的存在会影响入射到体模表面的次级带电粒子的产生，因此在真空以及源和平板浸没在空气中的球体中都确定了转换系数。将个人剂量当量的转换系数与根据最新国际放射防护委员会（ICRP）指南的建议计算出的适当防护量进行了比较。
