SEARCH FOR A 17-KEV NEUTRINO IN THE INTERNAL BREMSSTRAHLUNG SPECTRUM OF I-125

We have searched for evidence of the emission of a 17 keV neutrino in the internal bremsstrahlung (IB) spectrum accompanying the electron capture decay of I-125. The IB spectrum, recorded in a planar Ge detector, has 1.2 X 10(6) counts per keV at 17 keV below the 2p end point. We set an upper limit of 0.4% for the admixture of a 17 keV neutrino, at the 90% confidence level, and exclude a 0.8% admixture at the 99.6% confidence level. The Q(EC) value is found to be 185.77 +/- 0.06 keV. We also find that the recent calculations of Suric et al., which employ relativistic self-consistent-field atomic wave functions, reproduce the shape and relative intensity of IB partial spectra within a few percent.