High Precision Determination of the $^6$He Half-life

ORAL

Abstract

We performed a high precision measurement of the half-life of $^6$He. The motivation for this experiment lay not only in resolving a long-standing discrepancy between the previous most precise measured values of $806.7 \pm 1.5$~ms and $798.1 \pm 1$~ms, but also in serving as a solid basis for the extraction of the axial coupling constant $g_A$ by comparing the result to ab initio calculations. The measurement took place at the tandem accelerator of the Center for Experimental Nuclear Physics and Astrophysics of the University of Washington where we used the $^7$Li(d,$^3$He) reaction to produce $^6$He. We directed a 10~$\mu$A, 18~MeV deuteron beam onto a liquid lithium target station that delivers $\sim$$10^9$ atoms/s to a low-background experimental area where the amount of other short-lived isotopes, particularly 8Li, is greatly reduced. Here we present the design of the lithium target station, the $^6$He half-life experiment setup and the half-life determination process.

*This work was supported by DOE under grant DE-FG02-97ER41020

Authors

  • Ran Hong

    • University of Washington
  • Brent Delbridge

    • University of Washington
  • Alejandro Garcia

    • University of Washington
  • Gregory Harper

    • University of Washington
  • Andrease Knecht

    • University of Washington
  • Robert Robertson

    • University of Washington
  • Erik Swanson

    • University of Washington
  • Satoshi Utsuno

    • University of Washington
  • Douglas Will

    • University of Washington
  • Christopher Wrede

    • University of Washington
  • David Zumwalt

    • University of Washington
  • Peter Mueller

    • Argonne National Lab
  • Will Williams

    • Argonne National Lab