MEASUREMENT OF LI, L-ALPHA, L-BETA AND L-GAMMA X-RAY-FLUORESCENCE CROSS-SECTIONS IN HEAVY-ELEMENTS EXCITED BY 59.5 AND 123.6 KEV PHOTONS

L1, L alpha, L beta and L gamma XRF cross-sections were measured in he avy elements 73 less than or equal to Z less than or equal to 92 at ex citation energies of 59.5 and 123.6keV photons. Measurements were made using two excitation sources. The experimental values of the cross-se ctions were determined by measuring the absolute yield of L-subshell X -rays emitted from a target of a given element and thickness when it w as bombarded with a known flux of photons of given energy. It is obser ved that the measured L XRF cross-section values for the elements are in general agreement with the theoretical ones evaluated using L-subsh ell fluorescent yields (omega(i)) and Coster-Kronig transition probabi lities (f(ij)) based on the relativistic Dirac-Hartree-Slater theory. The present and previous measured and calculated values of the cross-s ections are tabulated to bring out the existing status of L X-rays pro duction cross-sections.