Perturbed angular distributions withLaBr3detectors: Thegfactor of the first10+state inCd

Abstract

The time differential perturbed angular distribution technique with LaBr 3 detectors has been applied to the I π = 11 2 − isomeric state (E x = 846 keV, τ = 107 ns) in 107 Cd, which was populated and recoil-implanted into a gadolinium host following the 98 Mo(12 C, 3n) 107 Cd reaction. The static hyperfine field strength of Cd recoil implanted into gadolinium was thus measured, together with the fraction of nuclei implanted into field-free sites, under similar conditions as pertained for a previous implantation perturbed angular distribution g-factor measurement on the I π = 10 + state in 110 Cd. The 110 Cd g(10 +) value was thereby reevaluated, bringing it into agreement with the value expected for a seniority-two νh11 /2 configuration.

Apparatus for in-beam hyperfine interactions and g-factor measurements: Design and operation

“…In addition, the development of lanthanum bromide (LaBr 3 ) scintillator detectors provides an opportunity to perform these experiments under new experimental conditions through their combination of good energy and time resolution. As a first application of LaBr 3 detectors to in-beam TDPAD techniques, the hyperfine field of Cd implanted into gadolinium was investigated [80] and related to an earlier measurement of the g-factor of the I π = 10 + state in 110 Cd by an integral IMPAD method [82]. Figure 24 shows an example of a TDPAD ratio function for 107 Cd implanted into gadolinium at a nominal temperature of 6 K following the 98 Mo( 12 C, 3n) 107 Cd reaction at a beam energy of 48 MeV.…”

“…For a second example of future work, the availability of LaBr 3 detectors has opened the possibility to measure the magnetic moments of relatively short-lived isomers (τ >∼ 10 ns) by time dependent perturbed angular distribution (TDPAD) methods following heavy ion reactions and recoil implantation into ferromagnetic hosts. Some preliminary studies of gadolinium hosts have been completed [80,83]. In addition to gadolinium, the rare earth metals terbium, dysprosium, holmium, and erbium all become ferromagnetic at temperatures between 20 K and 220 K. There is therefore the possibility to exploit the hyperfine fields in these ferromagnetic materials for nuclear moment measurements.…”

The Heavy Ion Accelerator Facility: Research Achievements and Aspirations

“…The first in-beam time-dependent perturbed angular correlations measured with LaBr 3 detectors were reported recently [31]. Further experiments of this type, which can precisely measure the g factors of states with lifetimes of a few nanoseconds, are planned.…”

Pushing the limits of excited-state g-factor measurements

“…[37] gives g(10 + ) = −0.29 (16), consistent with that of the expected seniority-two νh 11/2 configuration. A full account of this work has been published [38].…”