基于指甲在体EPR测量的核应急事故剂量评估方法

The dosimetry is an important prerequisite for nuclear emergency medical treatment after nuclear accident. The electron paramagnetic resonance (EPR) dosimetry of nails has the advantages in simplicity, measurement speed and on-site implementation, but the cutting process of the nails can introduce strong interference signal in the EPR spectra which is called mechanically induced signal (MIS) and it is difficult to distinguish from the radiation-induced signal (RIS). The in-vivo measurement of nails avoids the generation of MIS, and is expected to improve the dose range and accuracy of the dosimetry. In order to meet the key needs of in-vivo measurement, this project plans to develop a new type of microwave resonant cavity with narrow slit for sample detection, and establish a new method of in-vivo EPR nail based on the cavity.Then, the in vivo EPR method is used to measure the nails after irradiation with different doses, and the EPR spectra of the nails without mechanically induced signal are obtained. The dosimetric characteristics of the radiation induced signal are studied. And this project aims finally to establish a dose reconstruction method based on in-vivo nail EPR measurement in the nuclear accident.

评估伤员受照剂量是核应急医学救治的重要前提，指甲电子顺磁共振（EPR）测量具有简单、快速、可现场实现辐射剂量评估的优势，但指甲剪切会在EPR波谱中诱发显著的干扰信号（MIS）且难以与辐射诱发信号（RIS）分离，在体测量方法无需指甲剪切从而可避免MIS的产生，有可能显著改善辐射剂量评估的范围和精度。本项目以实现在体EPR测量最关键的微波谐振腔为突破点，研制新型的具有窄缝式样品检测口的专用微波谐振腔，并以此为基础建立指甲在体EPR测量新方法。然后利用该方法开展指甲在体EPR测量实验，获得无剪切诱发信号（MIS）干扰的指甲EPR波谱，研究其辐射诱发信号（RIS）的剂量学特性，最终建立基于指甲在体EPR测量的核应急事故剂量重建方法。

辐射伤员受照剂量评估是核应急医学救治的重要前提，指甲电子顺磁共振（EPR）测量具有简单、快速、可现场实施辐射剂量评估的优势，但指甲剪切会在EPR波谱中诱发显著的干扰信号（MIS）且难以与辐射诱发信号（RIS）分离，在体EPR测量方法无需指甲剪切从而可避免MIS的产生，可改善辐射剂量评估的范围和精度。本研究设计了指甲在体EPR测量用的新型谐振腔。该谐振腔采用TE101型微波场型，为该场型在EPR领域的创新应用；采用探测口式设计，为在体样本检测提供了可能；采用探测口位置收窄设计，提高了单位体积样品的检测灵敏度。设计了指甲在体EPR检测的基本原理和方法，研制了磁场扫描、磁场调制、控制和波谱处理等多种专用模块，搭建、完善了X波段指甲在体EPR检测装置，经试验验证达到了设计目标。开展了指甲在体EPR检测剂量学特性研究，获得了无机械诱发信号（MIS）干扰条件下的指甲在体EPR测量剂量学特性，包括本底信号分布规律、0-30Gy剂量-辐射诱发信号响应规律、辐射诱发信号衰减规律、剂量率和能量响应特性等。在此基础上，考虑快速实时剂量评估或较高精度剂量评估需求要素在内，设计了基于指甲在体EPR测量的事故剂量重建方法，参考相关标准规范拟制了《指甲在体电子顺磁共振剂量重建方法》。