Proton sputtering from polycrystalline Al surface interacting with highly charged ions at grazing incidence angle

摘要

Sputtering processes of protons from a polycrystalline Al surface interacting with Ar~(q+) (q = 3-14) ions at a grazing incidence angle (～0.5°) were investigated. The intensity of protons (I_H) detected in coincidence with scattered Ar atoms was measured as a function of q. I_H saturated at q ≥ 10, although it increased rapidly with q at 3 ≤ q ≤ 8. The angular distribution of protons with low kinetic energy (≤2 eV) began to deviate from the cosine distribution and assumed a rather flat equidistribution as q increased. To analyze the sputtering processes of protons at the grazing incidence angle, a modified model of the "above-surface potential sputtering model" was proposed by considering image acceleration of projectile ions.