L3-subshell vacancy state alignment in photon-atom collisions

Behavior of characteristic X-rays from a partial-transmission-type X-ray target

The angular distribution of characteristic X-rays using a partial-transmission tungsten target was analyzed. Twenty four tallies were modeled to cover a 360° envelope around the target. The Monte Carlo N-Particle (MCNP5) simulation results revealed that the characteristic X-ray flux is not always isotropic around the target. Rather, the flux mainly depends on the target thickness and the energy of the incident electron beam. A multi-energy photon generator is proposed to emit high-energy characteristic X-rays, where the target acts as a filter for the low-energy characteristic X-rays.

The polarization of X-rays and magnetic photoionization cross-sections for L3 sub-shell

The alignment of atoms with inner-shell vacancies resulting from ionization by photons was investigated by measuring the anisotropic emission of L shell X-ray lines. The X-ray line intensities were measured using an Si(Li) detector and radioisotope photon source in various emission angles. It was observed from measured intensities that Lalpha and Ll X-ray intensities for the L(3) sub-state depended on the emission angle, meaning that Lalpha and Ll X-rays had an anisotropic spatial distribution. Thus, the Lalpha to Ll intensity ratios for a set of elements were determined and alignment parameters for each element were obtained using these ratios. Also, the empirical values of the L(3) magnetic sub-state photoionization cross-sections for m(j)=3/2 and 1/2 were evaluated using the determined alignment parameters, sub-state photoionization cross-sections and the Coster-Kronig transition probabilities.