Charge transfer of 0.5-, 1.5-, and 5-keV protons with atomic oxygen: Absolute differential and integral cross sections

We report measurements of the absolute differential cross sections for charge-transfer scattering of 0.5-, 1.5-, and 5-keV protons by atomic oxygen at scattering angles between 0.01^∘{} and 2.6^∘{} in the laboratory frame. Absolute integral cross sections are also reported and compared with previously published total cross sections. The measurements were made using a flowing gas target, which consisted of a mixture of atomic and molecular oxygen produced by passage of O₂ through a microwave discharge. The cross sections for atomic oxygen were obtained by appropriate subtraction of the signal due to molecular oxygen from that due to the mixture of O and O₂. {} 1996 The American Physical Society.