  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 limited
detection range of few centimeters, posing a great risk to operators. The
potential in remote sensing makes femtosecond laser filament technology great
candidates for constructively address this challenge. Here we propose a novel
filament-based ionizing radiation sensing technology (FIRST), and clarify the
interaction mechanism between filaments and ionizing radiation. Specifically,
it is demonstrated that the energetic electrons and ions produced by {\alpha}
radiation in air can be effectively accelerated within the filament, serving as
seed electrons, which will markedly enhance nitrogen fluorescence. The extended
nitrogen fluorescence lifetime of ~1 ns is also observed. These findings
provide insights into the intricate interaction among ultra-strong light filed,
plasma and energetic particle beam, and pave the way for the remote sensing of
ionizing radiation.
