β-ν correlations from the beta decay of optically trapped ^38mK atoms
Abstract
The β-ν correlation parameter, a, for the 0^+arrow 0^+ decay of the ^38mK (lifetime 0.924s) is being measured using optically trapped atoms to place limits on the possible contribution of a scalar interaction to nuclear beta decay. The trap is used both to select the isomer from the more abundant ^38g.s.K, produced by the TRIUMF/ISAC on-line isotope separator and to confine typically 8,000 atoms of ^38mK in a volume less than 1mm in diameter. The β-ν correlation is measured by observing in a collinear geometry the positron in a Δ E-E telescope and the time of flight of the recoiling Ar nucleus in a micro-channel plate (MCP). The application of a uniform electric field along the detection axis toward the MCP allows separation of the Ar^0,Ar^+ and higher charge state Ar ions as well as increasing both their collection and detection efficiencies. The final data set includes > 500,000 β - ^38mAr coincidence events which are being used to determine a with a statistical precision of ∼0.003.
- Publication:
-
APS Division of Nuclear Physics Meeting Abstracts
- Pub Date:
- October 2003
- Bibcode:
- 2003APS..DNP.BG002G