STUDY OF X-RAY AND L-REC PHOTON EMISSIONS FROM HIGHLY IONIZED SWIFT AS-75 AND SE-80 PROJECTILES PASSING THROUGH A THIN CARBON FOIL

X-rays and L-shell radiative electron capture (L-REC) photons have bee n detected from highly ionized swift projectiles of As-75 and Se-80 pa ssing through a thin carbon foil at two incident projectile energies. All the K and L peaks show strong shifts towards higher energy as a re sult of multiple ionization of L-and M-shells. The K beta/K alpha inte nsity ratios have been found to be almost half of the value for the si ngly ionized atoms. The measured positions of various L and K x-ray pe aks and the measured K beta/K alpha intensity ratios have been attribu ted to certain types of electronic configurations based on the extensi ve multiconfiguration Dirac-Fock calculations. Generally, it has been found that the lowest-energy configuration plays a rather small role, but in contrast the excited configurations with holes in the L-shell a nd with occupied 3d, 4s, 4p, 4d or higher subshells seem to be very im portant. The relative L-REC cross section between higher and lower pro jectile energies shows excellent agreement with the results obtained u nder the non-relativistic dipole approximation.