Oxygen Surface-Density Measurements Based on Characteristic X-Ray Production by 100-keV Protons

Abstract

The oxygen‐K x‐ray yield from known thicknesses of aluminum oxide (1–70 μg O/cm²), bombarded by 100‐keV protons, indicates that oxygen surface density may be measured over the range from 50 to 0.004 μg/cm². At the lower limit, background is 50% of the signal. In thin oxide layers where proton energy loss and x‐ray absorption are negligible, the x‐ray yield I (x rays/proton) is related to the oxygen surface density t (μg/cm²) by I=(2.9×10⁻⁶)t.