A Method of Laser Isotope Separation Using Adiabatic Inversion

Abstract

This chapter proposes a laser isotope separation scheme based on the phenomenon of adiabatic inversion. A model of a multilevel system is presented in which population may be transferred from the ground state to higher excited states with nearly 100% efficiency, using laser pulses with field strengths varying slowly compared to the response time of the system. Adiabatic inversion in this model is sharply dependent upon the laser frequency, allowing separation of isotopes by taking advantage of small isotopic shifts in molecular energy level spacings. Furthermore, a criterion that determines if a laser pulse is adiabatic or not also depends sharply on frequency, thereby enhancing the separation. A time-dependent solution of the Schrö dinger equation for a laser pulse with a slow rise time and rapid fall time explicitly demonstrates the effectiveness of the method in selectively exciting only one of two different isotopes.