Abstract
High-energy cosmic protons passing through neutral upper-atmospheric
and magnetospheric regions strip electrons from target gas molecules, gen
erating transient, sub-meter-scale cylindrical micro-plasma channels. In
this study, we propose a comprehensive theoretical and numerical frame
work to model the spatial, temporal, and electrodynamic evolution of
these ionization trails. We explicitly incorporate Lorentz force dynam
ics, electronic Larmor gyrations (rL,e ∼ 0.011 − 0.05 m), and non-ideal
plasma transport mechanisms including ⃗ E×⃗ B and Gradient-B drifts along
boundary interfaces like the magnetopause.
Furthermore, we demonstrate that following the rapid exit/dispersion
of primary ionizing agents, the remaining unshielded ion core under
goes an electrostatic repulsion, establishing collective ion-acoustic den
sity oscillations. For typical upper-atmosphere core ion densities (n0 ∼
1014 −1016 m−3), we analytically derive the characteristic ion plasma fre
quency to span the Medium-to-High-Frequency (MF–HF) radio regime
(fpi ≈ 0.397 − 3.97 MHz) with a microsecond-scale decay driven by two
body dissociative recombination (τrec). Because this 0.397 − 3.97 MHz
emission falls below the typical ionospheric cutoff frequency (foF2), ter
restrial reflection shields ground detectors, rendering Low-Earth-Orbit
(LEO) satellite-based plasma wave receivers the primary candidate for
experimental validation.



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