β-γ angular correlation in 20Na

The β-γ angular correlation for the decay of ²⁰Na has been measured using a symmetric four detector system. The ²⁰Na activity was produced by the ²⁰Ne(p,n)²⁰Na reaction and transported by a He jet to the detector chamber. Care was exercised to ensure that the β source was well defined. Correlation data were acquired for θ_β-γ=90° and 180° as a function of positron energy. The correlation data were analyzed for both linear and quadratic energy dependence. We report as the best estimate for the linear coefficient (- 5.0 +/- 0.8) × 10^-3 MeV^-1 and for the quadratic coefficient (2.9 +/- 0.8) × 10^-4 MeV^-2. Incorporating the results with other measurements in the A=20 system, we find an upper limit for the second class current contribution to the correlation which is no more than 20% of the weak magnetism contribution and is consistent with zero. NUCLEAR REACTIONS Radioactivity ²⁰Na; measured β-γ angular correlation. Determined induced weak currents.