Atomic oxygen generators for surface studies in low Earth orbit

Abstract

Two facilities for the generation of energetic atomic oxygen beams have been developed to investigate the degradation of materials in low Earth orbit. An atomic oxygen generator using an ion beam method was used mainly for studying the effect of kinetic energies on surface reactions. Another generator combined pulsed supersonic valve and pulsed YAG laser systems for long-duration exposure experiments without maintenance. The velocity of atomic oxygen was measured by a retarding energy analyzer and a plasma time-of-flight analyzer. Increments of mass in silver films due to the formation of oxides show that the fluxes of atomic oxygen exceed 10 12 ~ 10 13 atoms/cm 2 s. X-ray photoelectron spectroscopy spectra of Ols on a single MoSi crystal exposed to energetic atomic oxygen showed the existence of energy dependence of the surface reaction.

Hyperthermal atomic oxygen interaction with MoS2 lubricants and relevance to space environmental effects in low earth orbit – effects on friction coefficient and wear-life

“…The energetic atomic oxygen reaction with materials used in the exterior of a spacecraft operated in low Earth orbit (LEO) is one of the key issues in future long-life spacecraft [1,2]. Much attention has been paid to polymer degradation due to atomic oxygen attack in the last decade.…”

Atomic-Oxygen-Flow Generation by Laser-Driven Plasma Wind Tunnel as Low-Earth-Orbit-Environment Simulator

“…A currently available unique approach for simulating high-speed atomic oxygen environments in the LEO is laser detonation [9,10]. However, the operation time of this type of simulator is restricted to several hundred microseconds owing to the use of a pulse laser.…”

Determination of the Energy Level of the Atomic Oxygen Flux Generated by the Space Simulation Apparatus Using a Thermal Modeling Method

“…One type of instrument previously used to determine atomic oxygen energy values is a retarding energy analyser as described by Tagawa [9]. However, a detailed description of the characterization technique, including its accuracy and limitations, was not reported.…”