Possibility of population inversion of Fe XVII ions in dense plasma conditions

We present the possibility of population inversion in 3p-3s quantum transitions of Ne-like Fe ions and the consequent laser action in the EUV range in the Centaurus X-3 (Cen X-3) x-ray pulsar. The effect of bulk motions of the ions on the laser gain is considered. The hydrodynamic Doppler broadened gain coefficients for the six lines of Ne-like Fe at 25.5 nm, 20.6 nm, 34.1 nm, 35.6 nm, 38.4 nm and 38.5 nm are calculated. The plasma velocity affects the laser gain by an order of magnitude 3. The gain coefficients are significant in the region of electron density 10¹⁸ < n_e < 10 ²² cm^-3 and electron temperature T_e 250-1000 eV. The lines at 25.5 nm and 20.6 nm have large linear amplification coefficient which implies that stimulated emission is possible in these lines under the physical conditions of the Cen X-3.