一种新型核辐射探测器——荧光核径迹探测器（FNTD）的研制和创新研究

Fluorescent nuclear track detector (FNTD) is a newly invented nuclear track detector in USA. It can record tracks of heavy charged particles, such as protons, αparticles, heavy ions and fission fragments. The shapes of tracks in FNTD are similar to those in solid state nuclear track detectors (SSNTD), such as CR-39. However, it does not need chemical etching to show the tracks, as the tracks in FNTD can be observed directly under optical microscope through the fluorescent light emitted from the trajectories of the particles. The tracks can be retained in FNTD for long time; But the images of tracks can be acquired within quasi-real time close to the time elapsed by electronic types of detectors. No dead-time loss of particles occurs in FNTD, which is opposite to the electronic types of detectors. The studies of the above fields mainly rely on CR-39 detectors up to now. The major role is expected to be played by FNTD detector in future. One of the advantages of FNTD in these studies is without interruption by track etching. FNTD can be used at high temperature (600 ℃), where electronic types of detectors can not work properly. .A cooperation study has been established between China Institute of Atomic Energy and Shanghai Institute of Silicate to carry out the synthesis of the crystal Al2O3:C,Mg, a mono-crystal of Al2O3 doped with minute amount of Carbon (C) and Magnesium (Mg). This FNTD crystal can be made only in USA up-to-date, and it is the unique FNTD detector material existed in the world until now. Another crystal: Al2O3:Mg is suggested and planned to be grown in this project, which is Al2O3 crystal doped with Mg only. The next aim is to dope alternative elements into Al2O3 crystal to find new materials of FNTD. Investigation of the properties of FNTD will be carried out in detail at heavy ion accelerators, and try to build a detection platform for the quasi real time measurements of FNTD, which can be followed by other institutions for FNTD study.

荧光核径迹探测器（FNTD）是美国最新发现的一种核径迹探测器，能记录质子、α粒子、重离子、裂变碎片等重带电粒子径迹。径迹形状与固体径迹探测器的相似，但不需要蚀刻，可用显微镜直接观察入射粒子轨道的荧光径迹。能长期保留径迹，并可“准实时”获取数据，与电子型探测器相似，但不受死时间限制。以前只能用CR-39研究的以上领域，以后可用FNTD在线测量，不必停机蚀刻。FNTD属高温探测器（600℃），用于电子型探测器不能使用的严酷环境。中国原子能院和上海硅酸盐所合作研制FNTD探测器材料：掺痕量C和Mg的Al2O3单晶Al2O3:C,Mg (目前只有美国能生产；是现有唯一FNTD材料)；研制只掺Mg的Al2O3:Mg，和掺杂其他元素的新组合，属本项目创新目标。用加速器重离子深入研究FNTD记录特性，并试制FNTD准实时探测平台，以供将来推广应用。

荧光核径迹探测器（FNTD）是美国最新发现的一种核径迹探测器，能记录质子、α粒子、重离子、裂变碎片等重带电粒子径迹。径迹形状与固体径迹探测器的相似，但不需要蚀刻，可用显微镜直接观察入射粒子轨道的荧光径迹。能长期保留径迹，与电子型探测器相似，但不受死时间限制。中国原子能科学研究院和中国科学院上海硅酸盐研究所合作研制FNTD探测器材料：研制只掺Mg的Al2O3:Mg,掺痕量C和Mg的Al2O3单晶Al2O3:C,Mg (目前只有美国能生产；是现有唯一FNTD材料)。我们还在原子能院建立了激光共聚焦显微镜系统。经过研究发现，只掺Mg的Al2O3:Mg无法观测到辐照离子，不能作为FNTD使用；掺痕量C和Mg的Al2O3单晶Al2O3:C,Mg在激光共聚焦显微镜下能够观测到一定的离子径迹;证明了FNTD的功能与掺碳有直接关系。但在研究中通过离子束分析方法和X射线荧光成像的元素分析手段均无法获得痕量碳的掺杂比例，需要以后针对这一点进一步研究分析来改善FNTD晶体制备的配方。