Half-Life of {sup 44}Ti as a Probe for Supernova Models

Recent measurements of galactic radioactivity with the Compton Gamma Ray Observatory reported {sup 44}Ti activity from the supernova remnant Cassiopeia A. The absolute amount of {sup 44}Ti provides a stringent test for current supernova models. The main uncertainty is presently the half-life of {sup 44}Ti . We report a new measurement of the half-life of {sup 44}Ti applying a novel technique using a mixed radioactive ion beam containing {sup 44}Ti as well as {sup 22}Na ions. This method allows the reliable determination of the half-life of {sup 44}Ti with high accuracy, t{sub 1/2}=(60.3{plus_minus}1.3) yr . The {sup 44}Ti abundance determined for Cassiopeia A with this half-life agrees with theoretical predictions within the observational uncertainties. {copyright} {ital 1998} {ital The American Physical Society}