Production of Positive Ions and Electrons in Collisions of 1–25-keV Protons and Hydrogen Atoms with CO, CO2, CH4, and NH3

Cross sections are reported for the production of slow, positive ions ${\mathrm{(\sigma }}_{+})$ and electrons ${\mathrm{(\sigma }}_{-})$ in collisions of 1–25‐keV protons and hydrogen atoms with CO, CO₂, CH₄, and NH₃. For H⁺ bombardment ${\sigma }_{-}$ is the total ionization cross section and ${\sigma }_{+}{\mathrm{\hspace{0.17em}-\hspace{0.17em}\sigma }}_{-}$ is the total electron capture cross section, ${\sigma }_{10}$ . For H⁰ bombardment ${\sigma }_{+}$ is a good approximation to the total ionization cross section. The results are compared with other results in different, overlapping energy ranges, and their application to the physics of planetary atmospheres is discussed.