Temperature Dependence in Erosion Rates of Polyimide Under Hyperthermal Atomic Oxygen Exposures

Introduction I T has been recognized that polyimide Ž lm, which is widely used in space applications, is eroded by atomic oxygen in a low Earth orbit (LEO) spaceenvironment.Becausepolyimidehas beenusedas a monitoringmaterial to evaluate atomic oxygen  uence, details of atomic oxygen reactionwith polyimide should be made clear under various atomic oxygen exposure conditions. One of the important factors that would in uence the reactivity of atomic oxygen is a sample temperature. However, there exists no ground-based report regarding an accuratemeasurementon the temperature dependence of polyimide erosion under the exposure to atomic oxygen beam with a translationalenergy of 5 eV, which corresponds to the collisional energy of atomic oxygen and materials in LEO. In this Note we are reporting the in situ results of temperature dependence in polyimide erosion under 5-eV atomic oxygen exposures. The effect of translational energy of the atomic oxygen beam on the temperaturedependenceof polyimideerosionwas also examined in the ground-basedexperiments.