Investigating a novel three-step excitation scheme for the ultra-trace analysis of plutonium via RIMS

A novel three-step excitation scheme for the ultra-trace analysis of $_{}^{242}$ Pu via resonance ionization mass spectrometry reported by Galindo-Uribarri et al. was investigated. Previously unknown optical isotope shifts for the second excitation and ionizing step for the plutonium isotopes $_{}^{238-240,244}$ Pu were measured. Saturation powers were recorded, and the efficiency was compared via electrodepositions of $_{}^{238}$ Pu with reference to the established scheme by Grüning et al. routinely applied on our setup. Both schemes share the same first excitation step and use a Rydberg state as ionizing step. The resonances for $_{}^{242}$ Pu published by Galindo-Uribarri et al. were confirmed.