Study of the nitrogen fluorescence yield under different environmental conditions in alpha radioactivity telemetry technique

Abstract

α Decay in the nuclear fuel cycle poses significant hazards due to its strong ionizing capability, making effective detection essential. Conventional detection methods require time-consuming scanning or sampling, often unsuitable for extreme environments and increasing radiation risks. Alpha Radioactivity Telemetry Technology (ARTT), a non-contact α radiation detecting method via secondary nitrogen fluorescence detection, addresses the limitations of traditional methods and has gained significant attention in recent years. However, limited research on α-induced nitrogen fluorescence under varying conditions hampers environmental corrections and quantitative analysis, constraining applications of ARTT. This article examines the dependence of α-induced nitrogen fluorescence yield on energy, pressure, humidity, and nitrogen–oxygen ratio, presenting measurements for all major 2P system emission bands. The results indicate that (1) fluorescence yield remains unaffected by deposited energy or α-ray energy within 1.5–4 MeV, (2) yield dependence on pressure and humidity aligns with theoretical expectations, but deviates for nitrogen–oxygen ratios, and (3) temperature has minimal impact, with a 30 °C variation around 25 °C affecting fluorescence yield by less than 5 %. In contrast, at 1 atm pressure, the yield of air is several hundred times greater than at zero pressure. At 25 °C, the yield of dry air is 1.4 times that of air at 100 % RH. And the one of pure nitrogen is over ten times higher than the gas with 20 % nitrogen and 80 % oxygen. This work provides a data foundation for environmental corrections in ARTT applications.