Resonance behaviour of the bremsstrahlung process in collisions of the low-energy electrons with alkali-metal clusters

The ordinary bremsstrahlung cross sections formed in collisions of low-energy electrons with clusters of lithium, sodium and potassium containing the 'magic' number of atoms (from 8 to 196) have been studied. Calculations are carried out through the continuum-continuum dipole matrix element in the length form, using the spherical jellium model for clusters and the density-functional approximation for the cluster potential and electronic wavefunctions. The resonance behaviour of the bremsstrahlung cross section is detected. The resonances are connected with the electron capture in quasi-bound states. Dependence of the resonance width and intensity on the projectile electron energy is studied.