Predicted thermal superluminescence in low-pressure air

TL;DR

This paper proposes that heating low-pressure air can create inverted atomic oxygen populations, leading to thermal superluminescence, which may explain observed atmospheric flashes during space shuttle reentry.

Contribution

It introduces a novel mechanism for thermal superluminescence in low-pressure air caused by oxygen dissociation and population inversion at high temperatures.

Findings

Overpopulation threshold at 2300-3000 K

Inverted atomic oxygen populations can produce superluminescent radiation

Potential explanation for atmospheric flashes during reentry

Abstract

It is shown that due to the dissociation of the molecular oxygen it is possible to obtain inverted population in low pressure air by heating. As a result of the quenching of the corresponding levels of the atomic oxygen the thermal superluminescent radiation is generated. It has been found that the threshold of the overpopulation is exceeded at the air temperature 2300-3000 K. Using this effect a possible mechanism for the generation of the flashes of the radiation in air observed on the airframe of the space shuttle during its descent and reentry in the atmosphere is suggested.