A high velocity recoil in vacuum determination of the g-factor and lifetime of the 2+ 1.98 MeV level in 18O

The g-factor of the 2+ 1.98 MeV excited state of 18O has been the subject of several measurements in recent years. These measurements indicate a value for the g-factor lower than that expected purely from two neutrons in (dsub(5/2))2 or (dsub(5/2),ssub(1/2)) configurations. The present measurement was undertaken to provide a more precise value for the g-factor and lifetime by using a sufficiently high recoil velocity that the 7+ (one electron) charge state is predominantly populated. This reduces uncertainties from assumptions about the hyperfine interaction from other charge states. (Auth.)