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Project Mjolnir: High efficiency real time mass separator and ion trap for Thorium-229

ORAL

Abstract

Mjolnir has been developed over the course of nearly a decade of research searching for the Thorium-229m isomer's exact energy. The isomer is of high interest as it could potentially be used as a nuclear clock transition with unprecedented precision. A low energy mass separator and ion trap for the real time separation and trapping of radioactive Thorium-229m isotopes has been developed to study the ~7.8 eV isomer transition. The apparatus consists of an ultra-high purity helium buffered electrostatic recoil gas stopper and RF carpet to guide ions from a radioactive source to the exit aperture. A natural helium jet created at the exit imparts momentum to the ions. The ions enter a large acceptance radio-frequency quadrupole (RFQ) ion guide which has a DC gradient applied to it. The ions are cooled in the residual helium buffer gas are damped and collimated and continuously injected into a radio frequency quadrupole mass separator (QMS). Ions are mass and charge selected in the QMS and exit into another RFQ for further beam collimation and cooling before being introduced into a linear ion trap. The entire apparatus has been designed to be able to continuously load the ion trap with Thorium-229/229m. The ion trap is physically small allowing a large solid angle to be covered by detectors to study of short-lived isomer decay. Project Mjolnir's latest status and results will be presented.

Presenters

  • Jason T Harke

    Lawrence Livermore Natl Lab

Authors

  • Jason T Harke

    Lawrence Livermore Natl Lab

  • Barbara Alan

    Lawrence Livermore Natational Laboratory

  • Aaron Hellinger

    Kansas State University

  • Aaron Tamashiro

    Lawrence Livermore National Laboratory

  • Jeremias Garcia-Duarte

    Lawrence Livermore National Laboratory

  • Yonatan Mishnayot

    Lawrence Livermore National Laboratory

  • William Dunn

    Kansas State University