Modification of a 5-eV Atomic-Oxygen Laser Detonation Source

Abstract

The present work describes the modification of a commercial pulsed laser detonation source, used for simulating the low Earth orbit 5-eV atomic-oxygen environment. In this facility the pulsed atomic-oxygen beam originatesfrom a plasma and is accompanied by high levels of vacuum-UV radiation. Thus, the exposure of materials to the atomic-oxygen beam is therefore an exposure to a combined atomic-oxygen and vacuum-UV environment creating synergistic erosion effects. A simple, low-cost system, based on the selective reflection of oxygen atoms, was developed in order to remove the vacuum-UV component from the atomic-oxygen beam. This system reflected about 50% of the original atomic-oxygen content. The vacuum-UV content in the reflected atomic-oxygen beam was reduced to 0.03% of its content in the original atomic-oxygen beam. Chemical changes occurring in Kapton HN and Tefzel (ethylene-tetrafluoroethylene copolymer) under vacuum-UV irradiation were used to prove that the reflected residual vacuum-UV radiation has no effect on the tested polymers.