Alpha radiation detection by using of Micro Pattern Gas Detectors in SQS mode

In gas detectors with UV absorbing gas mixture, the Self-Quenched Streamer (SQS) mode can be achieved following the proportional mode, which leads to appear the light column. In this study, the design, simulation and construction of three micro pattern gas-detector, THGEM, with different geometric dimensions are presented. Moreover, the ability of operation in SQS mode to determine incident rays position without using any conventional imaging system is investigated. In the presence of UV absorbing gas mixtures, the proportional mode of the gas detector operation is followed by SQS mode as soon as the visible light column appears at the ray entrance location. In the employed method, each THGEM hole as an image pixel can operate in the SQS mode with emerging a light column, independent of other holes. As a consequence, it can be used for alpha beam detection since the brightness of each hole at a certain voltage is proportional to the number of primary electrons entered the hole.