Laser-radio-frequency double-resonance spectroscopy of Rb84-87 isotopes trapped in superfluid helium

In this paper, we report on a laser spectroscopy measurement of Rb84-87 isotopes in superfluid helium (He II) at 1.8 K using laser-radio-frequency double-resonance spectroscopy. Rb ion beams (> 60 MeV/u) provided by the RIKEN projectile fragment separator (RIPS) were injected and trapped into He II. The stopping position of atoms in He II was precisely confirmed by laser spectroscopy. By optically pumping the trapped Rb isotopes, large atomic spin polarization (up to 40%) of each observed isotope in the ground state was achieved. The laser-radio-frequency double-resonance spectra were observed for stable Rb-85,Rb-87 isotopes as well as for unstable isotopes Rb-84,Rb-84m,Rb-86 by scanning a weak magnetic field with a fixed-frequency RF field. From the measured Zeeman splitting, nuclear spin values for Rb-84m,Rb- 84-87 isotopes were determined with reasonable accuracy. The number of ions injected into He II for the resonance spectra measurement was on the order of 10(4) particles per second. This work may open new opportunities for the study of various particles trapped in condensed helium in several fields.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000345463300003&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701OpticsPhysics, Atomic, Molecular & ChemicalSCI(E)2ARTICLEyangxf@ribf.riken.jp5null9