EUV emission spectra from excited multiply charged xenon ions produced in charge-transfer collisions

The extreme ultra-violet spectra of multiply charged xenon ions in the wavelength range of 6-24 nm are measured following the electron capture into excited states of slow Xeq+ (8 ⩽ q ⩽ 16) ions passing through He gas target to provide the spectroscopic information about Xe ions. The charge-state dependence of the 4d-nℓ (nℓ = 4f, 5p and 5f) transitions is obtained. Identification of the transition has been carried out by the comparison with the results of the previous theoretical calculation. The mechanisms of the electron capture and the optical emission are discussed utilizing the classical over-the-barrier model.