Gain Coefficients for Possible 4d-4p X-ray Lasers of Ni-like Nd, Sm, Eu, Gd, Ta and W Ions

Abstract

Populations of the 249 levels belonging to the ground configuration 3s23p63d10 and those of single excitations of a 3d, 3p and 3s electron to the orbitals of n=4 and 5 have been calculated for Nickel-like Nd, Sm, Eu, Gd, Ta and W ions for temperatures from 300 to 2000 eV and densities of 1.0  1021 and 1.0  1022cm-3. The gain coefficients for possible x-ray laser lines have also been calculated at these plasma conditions. The possible laser lines are transitions from levels 1 3/2 3/2 0 (3d 4d ) and 1 5/2 5/2 0 (3d 4d ) to levels of 1 3/2 1/2 1 (3d 4p ) , 1 5/2 3/2 1 (3d 4p ) and 1 3/2 3/2 1 (3d 4p ) . Estimation is made on the optimum plasma condition for x-ray laser gain.