Filament based ionizing radiation sensing

Accidental exposure to overdose ionizing radiation will inevitably lead to severe biological damage, thus detecting and localizing radiation is essential. Traditional measurement techniques are generally restricted to the detection range of few centimeters, posing a great risk to operators. The prospect in remote sensing makes femtosecond laser filament technology a great candidate for constructively addressing this challenge. Here we propose a novel filament-based ionizing radiation sensing method, and clarify the interaction mechanism between filaments and ionizing radiation from systematic experiment to microscopic theory. Specifically, it is demonstrated that the energetic electrons produced by <italic>α</italic> radiation in air can be effectively accelerated within the filament, serving as seed electrons, which will enhance nitrogen fluorescence. The extended nitrogen fluorescence lifetime of ~1 ns is also observed. Lastly, the combined microscopic model was elaborately established to quantitatively explain the modulation of nitrogen fluorescence emission from filament by ionizing radiation. These findings provide insights into the intricate interaction among ultra-strong light field, plasma and energetic particle beam, potentially suggesting a promising novel avenue for remote sensing of ionizing radiation.