离子收集式α探测器

LONG RANGE ALPHA DETECTOR

文章叙述自行试制的１台ＤＬ－０１型α探测器。利用流动空气将α粒子在空气中产生的电离离子送入离子电离室内进行电流测量，电流值的大小与α源活度成比例，流动空气可将离子传送至数十厘米甚至数米以上。该探测器的电流探测限为３５ｆＡ，灵敏度为（６．６６±０．１２）ｆＡ／Ｂｑ，在较宽的活度范围内，探测器有较好的线性。对在该装置上进一步降低本底电流及增加本底电流的稳定性、防止空气尘埃对电离室的污染、刻度仪器用α辐射源的选择等问题进行了讨论。仪器的刻度问题、污染物的大小以及不同部位的污染对测量结果所带来的影响等问题有待进一步研究。

The DL 01 α detector was desigend to measure the current created by the ions which are generated by the interaction of alpha particles with air and can be transported over significant distances(several meters) in a airflow generated by a small fan. The DL 01 α detector matched to a FJ 365 electrometer can measure the small electric current of ions up to the level of about 35 fA and the sensitivity of this detector is about(6 66±0 12) fA/Bq. Some problemes are discussed and put forward in the paper such as how to minimize and eliminate the noise sources and background current, how to select alpha sources to calibrate the detector, and how to control the influence due to different position of a source,in the measuring enclosure of the detector, and so on.