In situ erosion study of Kapton (R) using novel hyperthermal oxygen atom source

A novel hyperthermal oxygen atom source has been used to perform in situ er osion of Kapton(R) surfaces at room temperature, and these surfaces have be en examined using x-ray photoelectron spectroscopy before and after exposur e to different fluences of oxygen atoms and then after exposure to air. The data indicate that the initial attack site is the carbonyl portion of the Kapton by reaction with atomic oxygen to form carbon dioxide, which desorbs . The oxygen-to-carbon-atom ratio decreases from 0.23 to 0.11 during a 24-h exposure to a hyperthermal oxygen-atom flux of about 1.4 x 10(14) atoms/cm (2)-s. Following the 24-h oxygen-atom exposure, the sample was exposed to a ir for 3 h. The oxygen, nitrogen, and carbon concentrations return to value s similar to those obtained before the oxygen-atom exposure due to reaction with molecular oxygen in the air. Previous data from space and ground simu lations indicate an increase in the surface oxygen content with exposure to atomic oxygen and then air before analysis. The results obtained demonstra te that it is necessary to examine the chemical effects of oxygen-atom degr adation of Kapton without air exposure before surface characterization.