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CERN-INTC-2010-014; INTC-P-279. Magnetic dipole moment of doubly closed-shell plus one nucleon nucleus of 49 Sc. T. Ohtsubo Niigata University. The nuclear magnetic moment is a sensitive probe for the study of nuclear structure.
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CERN-INTC-2010-014; INTC-P-279 Magnetic dipole moment of doubly closed-shell plus one nucleon nucleus of 49Sc. T. Ohtsubo Niigata University
The nuclear magnetic moment is a sensitive probe for the study of nuclear structure. • The electromagnetic properties of nuclei that are doubly closed-shell plus or minus one nucleon are expected to be most approachable by theory, are most approachable to theory. Z,N = 2, 8, 20, 28, 50, 82, 126
m,Q moments around Z=20 20 20 28 2nd order configuration mixing Meson exchange current Isobar currents
Shell model calculation • Honma et al. used an effective GXPF1 interaction in their large-scale shell model calculation in the full pf shell.M. Honma et al., Phys. Rev. C69, 034335, (2004) • Speidel et al. describes shell model calculations with four effective interactions, FPD6, KB3, VHG and FPY.K.-H. Speidel et al., Phys. Rev. C62, 031301(R), (2000).
N=28 calc. Speidel K.-H. Speidel et al., Phys. Rev. C62, 031301(R), (2000).
Experiment • Nuclear orientation method (NICOLE) • Implanted nuclei are polarized by an hyperfine field in Fe at very low temperature. • Polarization is monitored by detecting b-ray asymmetry. • NMR is detected by change of b-ray asymmetry
Decay scheme Experimental condition • Frequency 140-170 MHz at Bext = 0.2 T • Temperature ~ 10mK • Relaxation time ~ 6 min 47ScFe data
b-ray asymmetry Wb 1/T Fraction factor = 1. Not consider backscattering. No background
Recent results in NICOLE 71CuFe 69AsFe N. J. Stone et al., Phys. Rev. C77, 014315,2008 V. V. Golovko et al., Phys. Rev. C72, 064316, 2005
Production of 49Sc • There is no data for the pure b emitter 49Sc because of the presence of many activities at the A=49 position from multiply charged ion species from which any 49Sc component cannot be separated. • Implant 49K or 39Ca with a Ti foil target plus CF4 leak plus plasma source, or a standard UCx target with surface ionizer. • 49Sc ~ 5 x 105/mC
Beam time estimation Cooling down/warm up Wide range resonance search Liq He/N2 charge Main run fine structure external field dependence
Collaboration Niigata University T. Ohtsubo, S. Ohya University of Oxford University of Tennessee N.J. Stone, C.R. Bingham University of Maryland J.R. Stone, W.B. Walters CSNSM C, Gaulard, L. Risag ari Institut Laue Langevin, ISOLDE U. Köster Toyama University K. Nishimura KEK S. Muto LPSC G. Simpson University of Novi Sad M. Veskovic