Decay of ^34,35Mg and Its Daughters

^34,35Mg isotopes were studied via beta decay to understand the structure of the isotopes in its decay chain including ^35,34,33Al, ^35,34,33Si, and ^35,34,33P, which are populated via beta decay, beta-delayed neutron emission, and beta-delayed two-neutron emission. ³⁵Mg and ³⁴Mg sit near the island of inversion at N=20. To understand their complex decay feeding, several hurdles were overcome. ³⁴Si is known to have a strongly populated low-lying state that decays via an E0 transition, hindering the beta-particle tagging. This must be accounted for when counting the beta-electrons. The beta-delayed neutron branching ratios from ³⁴Mg and Al are known but not directly measured, likewise in ³⁵Mg and Al. ³⁵Al is a scarcely studied nucleus with unknown transitions.

To observe the decay of ^34,35Mg, its respective decay chains, and beta-delayed daughters, an experiment was conducted at TRUIMF Laboratory using the GRIFFIN spectrometer, which included the use of HPGe detectors, plastic scintillator detectors, and new OGS neutron detectors. Analysis was done on the full data set, including tagging with a new OGS detector to cleanly separate out the beta-delayed neutron emission daughters. By setting up a gamma-gamma coincidence spectrum, new energy level transitions for ³⁵Al, ³⁴Al and ³⁵P were observed. Specifically, we believe we’ve found 7 new transitions for ³⁵Al and 5 new energy levels. The same is true for ³⁵P, with 7 new transitions and 2 new energy levels. From this analysis, we are able to extract the branching ratios and half-lives of ³⁵Mg and ³⁵Al as well as the beam intensity. The later will give an absolute decay rate to help determine the decay feeding intensity, including feeding to the ground states. The results from this analysis will be presented.