Desorption of excited molecules from solid nitrogen

TL;DR

This study investigates how excited nitrogen molecules desorb from solid nitrogen when irradiated with electrons, revealing a new desorption process linked to charged centers and recombination mechanisms.

Contribution

It introduces the first observation of N2* molecule desorption from solid nitrogen and proposes a mechanism involving charged center recombination.

Findings

First detection of N2* desorption from solid nitrogen.

Recombination of electrons with N4+ centers causes desorption.

Charged center dynamics influence radiation-induced phenomena.

Abstract

The role of charged centers in radiation-induced phenomena occurring in solid nitrogen irradiated with an electron beam was studied. The experiments were performed employing luminescence method and activation spectroscopy techniques - spectrally resolved thermally stimulated luminescence TSL and thermally stimulated exoelectron emission. To discriminate radiation-induced processes in the bulk and at the surface the samples were probed in depth by varying electron energy. Desorption of excited N2* (C3{\Pi}u) molecule was detected for the first time. The mechanism of this phenomenon based on recombination of electron with intrinsic charged center N4+ was proposed. The key role of N3+ center dissociative recombination in generation of N radicals is suggested.