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Pearson, M. R.

Publications and source records attributed to Pearson, M. R..

5 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2017

First determination of ground state electromagnetic moments of Fe 53

Here, the hyperfine coupling constants of neutron deficient 53 Fe were deduced from the atomic hyperfine spectrum measured using the bunched-beam collinear laser spectroscopy technique. The low-energy 53 Fe beam was produced by projectile-fragmentation reactions followed by gas stopping, and used for the first time for laser spectroscopy. Ground state magnetic-dipole and electric-quadrupole moments were determined as μ= –0.65(1)μ N and Q=+35(15)e 2 fm 2 , respectively. The multiconfiguration Dirac-Fock method was used to calculate the electric field gradient to deduce Q from the quadrupole hyperfine coupling constant, since the quadrupole coupling constant has not been determined for any Fe isotopes. Both experimental values agree well with nuclear shell model calculations using the GXPF1A effective interaction performed in a full fp shell model space, which support the soft nature of the 56 Ni nucleus.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2016

Charge radii of neutron deficient Fe 52 , 53 produced by projectile fragmentation

Bunched-beam collinear laser spectroscopy is performed on neutron deficient 52,53 Fe prepared through in-flight separation followed by a gas stopping. This novel scheme is a major step to reach nuclides far from the stability line in laser spectroscopy. Differential mean-square charge radii δ$\langle$r 2 $\rangle$ of 52,53 Fe are determined relative to stable 56 Fe as δ$\langle$r2$\rangle$ 56,52 =$-$0.034(13) fm 2 and δ$\langle$r 2 $\rangle$56,53=$-$0.218(13) fm 2 , respectively, from the isotope shift of atomic hyperfine structures. The multiconfiguration Dirac-Fock method is used to calculate atomic factors to deduce δ$\langle$r 2 $\rangle$. The values of δ$\langle$r 2 $\rangle$ exhibit a minimum at the N=28 neutron shell closure. The nuclear density functional theory with Fayans and Skyrme energy density functionals is used to interpret the data. As a result, the trend of δ$\langle$r 2 $\rangle$ along the Fe isotopic chain results from an interplay between single-particle shell structure, pairing, and polarization effects and provides important data for understanding the intricate trend in the δ$\langle$r 2 $\rangle$ of closed-shell Ca isotopes

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗