The Gamma-Ray Infrastructure For Fundamental Investigations of Nuclei, GRIFFIN, is a new experimental facility for radioactive decay studies at the TRIUMF-ISAC laboratory. The performance of the 16 highpurity germanium (HPGe) clover detectors that will make up the GRIFFIN spectrometer is reported. The energy resolution, efficiency, timing resolution, crosstalk and preamplifier properties of each crystal were measured using a combination of analogue and digital data acquisition techniques. The absolute efficiency and add-back factors are determined for the energy range of 80 -3450 keV. The detectors show excellent performance with an average over all 64 crystals of a FWHM energy resolution of 1.89(6) keV and relative efficiency with respect to a 3"x3" NaI detector of 41(1)% at 1.3 MeV.

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The island of inversion for neutron-rich nuclei in the vicinity of N = 20 has become the testing ground par excellence for our understanding and modeling of shell evolution with isospin. In this context, the structure of the transitional nucleus 29 Mg is critical. The first quantitative measurements of the single-particle structure of 29 Mg are reported, using data from the d (28 Mg, p γ) 29 Mg reaction. Two key states carrying significant = 3 (f-wave) strength were identified at 2.40 ± 0.10 (J π = 5/2 −) and 4.28 ± 0.04 MeV (7/2 −). New state-of-the-art shell-model calculations have been performed and the predictions are compared in detail with the experimental results. While the two lowest 7/2 − levels are well described, the sharing of single-particle strength disagrees with experiment for both the 3/2 − and 5/2 − levels and there appear to be general problems with configurations involving the p 3/2 neutron orbital and core-excited components. These conclusions are supported by an analysis of the neutron occupancies in the shell-model calculations.

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