Beta-delayed neutron decay of ³³Na

Beta-delayed neutron decay of 33Na has been studied using the on-line mass separator ISOLDE. The delayed neutron spectra were measured by time-of-flight technique using fast scintillators. Two main neutron groups at 800(60) and 1020(80) keV were assigned to the 33Na decay, showing evidence for strong feeding of states at about 4 MeV in 33Mg. By simultaneous β-γ-n counting the delayed neutron emission probabilities P1n = 47(6)% and P2n = 13(3)% were determined. The half-life value for 33Na, T1/2 = 8.0(3) ms, was measured by three different techniques, one employing identifying gamma transitions and two employing beta and neutron counting. © 2002 Elsevier Science B.V. All rights reserved.