Published in Physical Review Letters, Volume 79, Issue 3, July 21, 1997, pages 375-378.
Copyright © 1997 American Physical Society. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Physical Society. The following article appeared in Physical Review Letters and may be found at http://dx.doi.org/10.1103/PhysRevLett.79.375.
NOTE: At the time of publication, the author Paul F. Choboter was not yet affiliated with Cal Poly.
A magneto-optic trap (MOT) can provide a well-polarized, backing-free, localized source of radioactive atoms for β-decay experiments. We have trapped approximately 6000 atoms of 38Km ( t1/2 = 0.925s) and 2000 atoms of 37K (1.226 s) produced at the TRIUMF on-line separator TISOL in a vapor-cell MOT. We have measured optical isotope shifts and deduced the nuclear charge radii, which show an unusual lack of change at the neutron number N = 20 shell closure. Plans include a search for scalar contributions to the β+- ν correlation in the 0+→0+ decay of 38Km.