Effect of magnetic field on isotope-selective photoionization of atomic samarium using polarized lasers

Abstract

The effect of an external magnetic field on the isotopic selectivity in a two-color three-step polarization-based isotope-selective photoionization of atomic samarium has been studied. Isotopeselective photoionization of samarium is realized through a level scheme having total angular momentum (J) sequence 0-1-1-continuum by using two lasers linearly polarized in the same direction and the isotopic selectivity is measured by varying the magnetic field strength perpendicular to the laser polarization axis while keeping the delay between the laser pulses fixed and vice versa. The experimental data have been analyzed and compared with the results of the numerical calculations. The magnetic field perpendicular to the laser polarization axis present in the laser-atom interaction region has been found to degrade the isotopic selectivity. Further, the Lande factor (g J ) of the excited energy level 16 690.76 cm −1 (J=1) of samarium has been determined from the observed oscillation in the isotopic selectivity. The value of g , J thus obtained, is in good agreement with that reported in the literature.

Numerical studies of isotopic selective photoionization of ytterbium in a three-step ionization scheme

“…With the consideration of high 176 Yb abundance, narrower bandwidths are required for excitation lasers. Isotopic selectivity in LIS process is generally achieved from the isotope shift by using narrow bandwidth lasers, and another way is based on the atomic alignment by laser polarization [26] . Isotopes with hyperfine structures are allowed to be excited, while isotopes with zero nuclear spins are prohibited from being exited by choosing proper photoionization schemes and laser polarization combinations.…”