Multi-Resonant Laser Isotope Separation for Sr Enrichment

Multi-Resonant Laser Isotope Separation (MRLIS) provides a high-efficiency, compact alternative to traditional methods like gas centrifuges, electromagnetic separation, and conventional atomic vapor laser isotope separation. We report on the laboratory development and initial implementation of a MRLIS system for producing enriched strontium isotopes, targeting applications such as metabolic tracers and precision tests of quantum mechanics. Our approach integrates a planar Fabry-Pérot cavity to enable efficient, continuous-wave (CW) photoionization through resonant intracavity power buildup. This design overcomes the challenges of low photoionization cross-sections and limited CW laser powers by delivering high intracavity power density across an ultra-large mode volume, thus saturating ionization of the targeted isotope. We present progress and simulation results demonstrating isotopic enrichment in Sr, including simulated enrichment factors and ionization yields.