Measurement of Hyperfine Structure of Au Atom in Superfluid Helium

Abstract

"OROCHI (Optical Radioisotope atom Observation in Condensed Helium as Ion-catcher)" is new laser spectroscopy technique to determine nuclear spins and moments of exotic nuclei. In this technique, we utilize the combination of optical pumping and double resonance techniques to measure Zeeman splittings and hyperfine splittings of atoms in superfluid helium (He II). Recently, we have observed the hyperfine splitting transition of stable 197 Au in He II. This success has distinctly shown the applicability of OROCHI to the exotic Au isotopes. In this report, we present the achieved atomic spin polarization (more than 80%) and the following observation of the double resonance spectra of Au atoms in He II.