Peimel-Stuglik Z, Fabisiak S
Laboratory for Measurement of Technological Doses, Institute of Nuclear Chemistry and Technology, Dorodna 16, 03-195 Warsaw, Poland.
Spectrochim Acta A Mol Biomol Spectrosc. 2006 Mar 13;63(4):855-60. doi: 10.1016/j.saa.2005.10.016. Epub 2006 Feb 21.
EPR dosimetry method with alpha-alanine as radiation sensitive material (RSM) is widely used in high dose dosimetry laboratories. However, it is not suitable for routine industrial applications mainly because of difficult EPR measurement procedure. In order to simplify quantitative EPR dosimetry measurements Yordanov and Gancheva developed so-called "self-calibrated" (sc) dosimeters consists of RSM (alpha-alanine, sugar, other ones), Mn2+/MgO as internal EPR intensity standard (IES) and a binder. The aim of this work was to check dosimetric properties of two experimental batches of sc EPR dosimeters with alpha-alanine and sugar as RSM, Mn2+/MgO as IES and paraffin as a binder. The percentage content of the components was 60, 5 and 35% (w/w), respectively. It was established that the investigated alanine sc-dosimeters are about two times more sensitive than the sugar ones. The dose-response coefficient, K(dr) of sc-alanine dosimeters was stable in all investigated dose range from 1 to 23 kGy. The K(dr)-value of sugar sc-dosimeters decreased with the dose what was in a contradiction to the results pointed to the high stability of radiation generated sugar radicals. The observed effect arose probably from the special chemical procedure used for the sc-sugar dosimeters production. The results confirmed an expectation that the position of sc dosimeter in the cavity is not important factor for accurate dose evaluation. It allows to read-out dosimetric signals in shorter time, with lower uncertainty and on less sophisticate EPR-spectrometers than that commonly used till now. The main shortcomings of sc dosimeters are: (a) the limitation of RSM suitable for sc dosimeters to these ones having strictly linear signal to dose characteristic; (b) necessity to assure very good homogeneity of dosimeter material; and (c) the cost of IES present in the amount of some percent in each sc dosimeter.
以α-丙氨酸作为辐射敏感材料（RSM）的电子顺磁共振（EPR）剂量测定法在高剂量剂量测定实验室中被广泛使用。然而，它并不适用于常规工业应用，主要原因是EPR测量程序复杂。为了简化EPR剂量测定的定量测量，约尔达诺夫和甘切娃开发了所谓的“自校准”（sc）剂量计，其由RSM（α-丙氨酸、糖等）、作为内部EPR强度标准（IES）的Mn2+/MgO和一种粘合剂组成。这项工作的目的是检验两批以α-丙氨酸和糖作为RSM、Mn2+/MgO作为IES以及石蜡作为粘合剂的实验性sc EPR剂量计的剂量学特性。各成分的质量百分比分别为60%、5%和35%（w/w）。结果表明，所研究的丙氨酸sc剂量计的灵敏度约为糖sc剂量计的两倍。sc-丙氨酸剂量计的剂量响应系数K(dr)在1至23 kGy的所有研究剂量范围内都很稳定。糖sc剂量计的K(dr)值随剂量降低，这与所指出的辐射产生的糖自由基具有高稳定性的结果相矛盾。观察到的这种效应可能源于用于生产sc-糖剂量计的特殊化学程序。结果证实了这样一种预期，即sc剂量计在腔体中的位置对于准确的剂量评估不是重要因素。与目前常用的相比，它能够在更短的时间内读出剂量学信号，具有更低的不确定性，并且可以在不太复杂的EPR光谱仪上进行。sc剂量计的主要缺点是：（a）适用于sc剂量计的RSM局限于具有严格线性信号与剂量特性的那些；（b）需要确保剂量计材料具有非常好的均匀性；以及（c）IES的成本，其在每个sc剂量计中的含量为百分之几。
