Addressed herein, a new monitoring method for alpha surface contamination based on the function of a thick gaseous electron multiplier (THGEM) in a self-quenching streamer mode (SQS) has been introduced. SQS mode detectors can detect alpha surface contamination in two dimensions. In the current study, the ability of thick gas electron multiplier detectors in SQS mode for two-dimensional monitoring of alpha surface contamination has been investigated by two Am-241 sources with activities equal to 33 and 150 kBq.m-3. It has been found that the brightness is stronger in front of stronger sources. This may be attributed to the difference in contamination levels. It was also observed that the spatial resolution of the contamination rate depends on the number of holes per unit area of each THGEM. The advantage of this system is the ability to determine both the location and intensity of surface contamination with no need for an electronic multiplier or reader system.
• A new method for measuring alpha particles using the function of thick electronic multipliers in natural glow mode.
• Two-dimensional detection of alpha particles including fast response time and good spatial resolution.
• Determine the location and intensity of surface contamination with no need for electronic multiplier or reader system.