We propose laser-based methods for the production of nuclear spin hyperpolarized molecules. Following pulsed, coherent excitation from ground-state molecules in a molecular beam to specific rotational |J mJ> states, the resulting hyperfine polarization beating produces desirable nuclear spin mI population distributions and mI-mJ correlations at specific later times. At this point, selective dissociation can be used to remove undesired spin states, or a strong magnetic field can be applied, which later can be removed adiabatically to transfer the population-enhanced nuclear spin configurations to the desired nuclear spin state. Finally, the polarization beating is stopped, and the molecules are stored by cryogenic trapping. We show how these methods can be used to produce the long-lived singlet state of N152O and ortho H2O , which have been proposed as magnetic tracers. We discuss how large production rates between 1 and 100 μ mol /s with singlet-state populations between 35% and 100% can be achieved.
Physical Review A
- Pub Date:
- September 2015
- Fine and hyperfine structure;
- Nuclear resonance and relaxation;
- Other topics in molecular properties and interactions with photons;
- Atomic and molecular beam sources and techniques