The structure of Kα and Kβ lines radiated from highly ionised plasmas

The K-alpha and K-beta radiation from Fe, Ni and Ti plasmas in a low inductive spark has been investigated both experimentally and theoretically. A high-dispersion and high-resolution Johann crystal spectrograph has been used for the measurements. The theoretical analysis is based on relativistic perturbation theory with a zero-order model approximation. Some K-alpha and K-beta spectra features are qualitatively explained and some K-beta lines are identified for the first time. It has been shown that the observed time and space integrated spectrum is due mainly to the low M-shell ions. The calculation shows that this qualitatively explains the long-wavelength K-alpha plasma radiation shift relative to the solid state K-alpha line. The K-alpha radiation from high ions would be shifted to the opposite side.