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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. - PowerPoint PPT Presentation
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the 36th Meeting of the INTC, 2010.2.4, CERN
Magnetic dipole moment of doubly closed-shell plus one
nucleon nucleus of 49Sc.
T. Ohtsubo
Niigata University
CERN-INTC-2010-014; INTC-P-279
the 36th Meeting of the INTC, 2010.2.4, CERN
• 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
the 36th Meeting of the INTC, 2010.2.4, CERN
42Ca 44Ca 46Ca
42Ti 44Ti 46Ti 48Ti 50Ti
39K 40K 41K 42K 43K 44K 45K 46K 47K 48K38K
39Ca 40Ca 48Ca41Ca 43Ca 45Ca 47Ca 49Ca
40Sc 41Sc 42Sc 43Sc 44Sc 45Sc 46Sc 47Sc 48Sc 49Sc 50Sc
41Ti 43Ti 45Ti 47Ti 49Ti 51Ti
: known Q : known
,Q moments around Z=20
20
20 28
2nd order configuration mixingMeson exchange currentIsobar currents
the 36th Meeting of the INTC, 2010.2.4, CERN
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).
the 36th Meeting of the INTC, 2010.2.4, CERN
40 42 44 46 48 50A
A=40
5.0
6.0
[N]
A=48
Schmidt value
Honma
Speidel
magnetic moment of odd A Sc isotopes
N=28 calc. Speidel
K.-H. Speidel et al., Phys. Rev. C62, 031301(R), (2000).
the 36th Meeting of the INTC, 2010.2.4, CERN
Experiment
• Nuclear orientation method (NICOLE)• Implanted nuclei are polarized by an
hyperfine field in Fe at very low temperature.
• Polarization is monitored by detecting -ray asymmetry.
• NMR is detected by change of -ray asymmetry
the 36th Meeting of the INTC, 2010.2.4, CERN
Decay scheme Experimental condition
4921Sc
4922Ti
7/2
7/299.94%
Q = 2006 keV
57.2 m0
0
• Frequency 140-170 MHz at Bext = 0.2 T• Temperature ~ 10mK• Relaxation time ~ 6 min
47ScFe data
the 36th Meeting of the INTC, 2010.2.4, CERN
-ray asymmetry
0.6
0.7
0.8
0.9
1
1.1
1.2
1.3
1.4
1 10 100 1000 1/T
W
Fraction factor = 1. Not consider backscattering. No background
the 36th Meeting of the INTC, 2010.2.4, CERN
ISOLDE/NICOLE
the 36th Meeting of the INTC, 2010.2.4, CERN
Setupsuperconducting magnet
Fe foil (cold finger)
counter
counter
49Ca(49K)
polarized field
49Sc
the 36th Meeting of the INTC, 2010.2.4, CERN
Recent results in NICOLE
V. V. Golovko et al., Phys. Rev. C72, 064316, 2005
N. J. Stone et al., Phys. Rev. C77, 014315,2008
71CuFe 69AsFe
the 36th Meeting of the INTC, 2010.2.4, CERN
Yields of Sc isotopes at ISOLDE
Nucleus yield at ISOLDE
(ions/C)
target material
47Sc 3.0E+7 Ti
2.5E+6 Ti48Sc 7.7E+6 Ta50Sc 3.6E+3 Ta
the 36th Meeting of the INTC, 2010.2.4, CERN
Production of 49Sc
• There is no data for the pure 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/C
the 36th Meeting of the INTC, 2010.2.4, CERN
Beam time estimation
Nucleus Prod. Target Time(Shifts)
49Ca , 49K
(49Sc)Ti/UCx 8
47Sc Ti 4
total 12
Cooling down/warm upWide range resonance searchLiq He/N2 charge
Main run fine structure external field dependence
the 36th Meeting of the INTC, 2010.2.4, CERN
CollaborationNiigata 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
the 36th Meeting of the INTC, 2010.2.4, CERN
end
the 36th Meeting of the INTC, 2010.2.4, CERN
the 36th Meeting of the INTC, 2010.2.4, CERN
0.2 T
0.4 T
0.6 T
frequency (MHz)144 146 148 150 152
47ScFe
the 36th Meeting of the INTC, 2010.2.4, CERN
J. Rikovska et al, Phys. Rev. Lett. 85, 1392, 2000
the 36th Meeting of the INTC, 2010.2.4, CERN
NMR-ON
H = -μ ・B= -gμ N I・B= -gμ N B0Iz
Em = <m| H | m>
= -gμ N B0m
B0
I = 5 case
energy
m = -5
m = +5
Magnetic Interaction
B = 0 B = 0
magnetic quantum number
μ
.
.
.
Population am ∝ e-Em/kT
low temperaturehigh field
Polarization(Orientation)
Boltzmann ditribution
Zeeman split
the 36th Meeting of the INTC, 2010.2.4, CERN
Ge detector
population population
γ -ray angular distribution
rf frequency
γ-r
ayde
tect
ion
hν =Δ E
transition
resonance
the 36th Meeting of the INTC, 2010.2.4, CERN