Electromagnetic moments of short lived beta emitters F-21, Mg-23, Si-27 and Ca-39

The beta-NMR spectra of F-21, Mg-23, Si-27 and Ca-39 which were produced in heavy ion collisions and implanted in various crystals have been observed. The magnetic moments of F-21 and Si-27 were determined to be \mu(F-21)\ = 3.9194 +/- 0.0012 mu(N) and \mu(Si-27)\ = 0.8653 +/- 0.0003 mu(N), respecti vely. The electric quadrupole coupling constants were determined for the fi rst time to be \eqQ(F-21 in MgF2)/h\ = 9.94 +/- 0.09 MHz, \eqQ(Mg-23 in MgF 2)/h\ = 1.96 +/- 0.06 MHz, \eqQ(Si-27 in Al2O3)/h\ = 1.90 +/- 0.12 MHz, \eq Q(Ca-39 in CaCO3)/h\ = 0.60 +/- 0.04 MHz. From the present eqQ/h, the Q mom ents were deduced as \Q(F-21)\ = 110 +/- 22 mb, \Q(Mg-23)\ = 114 +/- 3 mb, \Q(Si-27)\ = 60 +/- 13 mb and \Q(Ca-39)\ = 36 +/- 7 mb. The present data we re compared with the theoretical values obtained by the OXBASH shell model code.