Tanaka Kenichi, Endo Satoru, Toyoda Shin, Tieliewuhan Eldana, Romanyukha Alex, Hoshi Masaharu
Research Institute for Radiation Biology and Medicine, Hiroshima University, 1-2-3 Kasumi, Hiroshima, Japan.
Radiat Environ Biophys. 2007 Aug;46(3):215-20. doi: 10.1007/s00411-007-0102-7. Epub 2007 Apr 12.
Recently, a numerical method was proposed to correct the imaging plate (IP) response to (90)Sr concentration in tooth samples, depending on the sample thickness. This is important to quantify any (90)Sr concentration in teeth, which in turn is necessary to determine any (90)Sr incorporation of a person retrospectively. Although the final goal will be to evaluate the (inhomogeneous) spatial distribution of (90)Sr inside tooth samples precisely, the present study was restricted -- as a first step -- to the evaluation of (90)Sr in teeth assuming a uniform (90)Sr distribution. A numerical method proposed earlier was validated experimentally in the present study by measuring the IP response to standard sources of various thicknesses and (90)Sr concentrations. For comparison, the energy deposition of the beta-rays emitted by (90)Sr in the IP -- which is considered to be proportional to the IP luminescence signal -- was calculated for the various sample thicknesses involved, by means of the MCNP-4C code. As a result, the measured IP response could be reproduced by the calculations within the uncertainties, depending on the thickness of the standard sources. Thus, the validity of the proposed numerical method to correct the IP response for sample thickness has successfully been demonstrated.
最近，有人提出了一种数值方法，用于根据样品厚度校正成像板（IP）对牙齿样品中（90）Sr浓度的响应。这对于量化牙齿中的任何（90）Sr浓度很重要，而反过来，这对于追溯确定一个人的任何（90）Sr摄入量也是必要的。尽管最终目标是精确评估牙齿样品内部（90）Sr的（不均匀）空间分布，但作为第一步，本研究仅限于在假设（90）Sr分布均匀的情况下评估牙齿中的（90）Sr。本研究通过测量IP对各种厚度和（90）Sr浓度的标准源的响应，对先前提出的一种数值方法进行了实验验证。为了进行比较，借助MCNP - 4C代码，针对所涉及的各种样品厚度，计算了（90）Sr在IP中发射的β射线的能量沉积，该能量沉积被认为与IP发光信号成正比。结果，根据标准源的厚度，在不确定性范围内，计算结果能够重现测量的IP响应。因此，已成功证明了所提出的用于校正样品厚度的IP响应的数值方法的有效性。
