Electron-impact ionization-rate coefficients for lithiumlike nitrogen and oxygen

The electron-impact ionization-rate coefficients for lithiumlike nitrogen and oxygen are obtained from the time evolution of spectral lines emitted by a hot plasma. The plasma is produced in a 37-kJ theta pinch. Laser scattering diagnostics indicate that Nₑ≈4×10¹⁵ cm^-3 and kTₑ≈80 eV during the time of principal interest. Under these conditions, the ionization-rate coefficient for lithiumlike nitrogen is (7.4±{}2.2)×{}10^-10 cm³ s^-1, and that for lithiumlike oxygen is (4.1±{}1.2)×{}10^-10 cm³ s^-1. The rate coefficients measured here and all other measurements of lithiumlike ionization rate coefficients are compared to calculations of the ground-state ionization-rate coefficient and the total-ionization-rate coefficient.