Feasibility Study on a γ-rays Source Detector by Image Processing Technology

Abstract

The purpose of this feasibility study was to assess a new image processing technology to detect γ-rays sources by using a cloud chamber. A simple cloud chamber was built to generate alcohol super saturation state. A few mm tracks are generated by incident γ-rays in the cloud chamber and the number of tracks is proportional to the number of incident γ-rays. The images in the cloud chamber were captured by a USB camera connected to a PC and the captured images were saved on the PC to manipulate the images. As the concept, lead plates were systematically arranged to shield a part of incident γ-rays. The device has the possibility to distinguish the direction of a γ-rays source by monitoring the difference of an amount of track in each area separated by each lead plate. In this paper, the chamber was used to survey differences of the response for both a point source and a surface source reproduced by some lead collimators approximately. The response for two cases of γ-rays sources was calculated by PHITS simulation code. As a result, it was found that there was enough relationship between dose rate and the amount of the observed tracks of Compton electrons. In comparison with experimental data, PHITS simulation code reproduced the tracks in captured image. The code can be used as the tool to develop the new cloud chamber with some lead plates.