Magnetic and Quadrupole moments of Cu isotopesWith collinear laser spectroscopy
Pieter Vingerhoets18/11/2009
Motivation: The region of the nuclear chart
30
28
29Cu78
Cu59
Zn69
Ni67
Zn70
Zn71
Zn72
Zn73
Zn74
Zn75
Zn76
Zn77
Zn78
Zn79
Zn80
Cu71
Cu72
Cu73
Cu74
Cu75
Cu76
Cu77
Cu78
Cu79
Ni68
Ni69
Ni70
Ni71
Ni72
Ni73
Ni74
Ni75
Ni76
Ni77
Ni78
Zn57
Zn58
Zn59
Zn60
Zn61
Zn62
Zn63
Zn64
Zn65
Zn66
Zn67
Zn68
Cu55
Cu56
Cu57
Cu58
Cu59
Cu60
Cu61
Cu62
Cu63
Cu65
Cu68
Cu69
Cu70
Cu64
Cu66
Cu67
Ni53
Ni54
Ni55
Ni56
Ni57
Ni58
Ni59
Ni60
Ni61
Ni62
Ni63
Ni64
Ni65
Ni66
28 50
Cu63
Cu65
Cu68
Cu69
Cu70
Cu64
Cu66
Cu67
40
n1g9/2 gets filledn2p3/2 1f5/2 2p1/2
57 59 61 63 65 67 69 71 73 75
Franchoo et al. Phys.Rev.C. 2001, Stefanescu et al, Phys.Rev.Lett. 2008
?
E(keV)
1000
3/2-
5/2-
1/2-
2p3/2
1g9/2
40
2p3/2
1f5/2
2p1/2
40
1f5/2
2p1/2
1g9/2
75Cu
4028
3
32S1/2
32P3/2
21
0
2
1
F
I(67Cu)=3/2
Relative frequency (MHz)
cou
nts
refref
BQ Q
B
I refref ref
AI
A I
1 (3/ 4) ( 1) ( 1) ( 1)
2 2 (2 1) (2 1)
( 1) ( 1) ( 1)
C C I I J JE C
I I J JA
C F F I I J
B
J
F=I+J
Laser spectroscopy: experimental technique
+
Laser spectroscopy: experimental setup
+
+++++++
mirror
electrostatic deflectors Ion beam
Post-acceleration voltage
charge exchange Cell (200oC)
Photomultiplier tubes +
From HRS
++
+++
RFQ beam cooler/buncher
Dye laser
2
1
1laser transition
2 40
2 20
1( )
M c
q M cU
Varying post-accelerationvoltage to scan frequency:
Wavelength 648nm,Doubled to 324nm
Mark
+
72Cu: spin confirmation of 2, a challenge for nuclear shell model
>40 hours measured, 5 out of 6 peaks resolved
K. Flanagan
2.5 hours measured, 6 out of 6 peaks resolved
2007, without ISCOOL buncher
2008, with ISCOOL buncher
Relative frequency (MHz)
cou
nts
Relative frequency (MHz)
cou
nts
J.C. Thomas, Phys.Rev.C 2006
40
2p3/2
1f5/2
2p1/2
1g9/2
40
72Cu: spin confirmation of 2, a challenge for nuclear shell model
(pp3/2 ng9/23) (3,4,5,6)-
(pf5/2 ng9/23) (2,…,7)-
(pp3/2 np1/2-1g9/2
4) (1,2)+
μexp(72Cu)= -1.3460(5) mN
(m pf5/2 ng9/23; 2-) :
memp (2-) = -1.94 mN
(m pp3/2 np1/2-1g9/2
4; 2+): memp (2+) = +1.44
mN
Experiment Realistic interaction
(3-)
(4-)
(1+)
3-6-
4-
2+
2-
5-
1+
0
137
219270
376
016
140
235
387418431
2-
(6-) t1/2=1.76ms
72Cu
What would we expect?empirical magnetic moments
(2)
E(keV) E(keV)
75Cu: Spin assignment
- Yield ~ 5 104 ions/μC- Accumulation time 100ms- Background reduction of 103
SPIN OF 75Cu IS 5/2
A (2S1/2) = +1592(1) MHzB(2P3/2) = -34(2) MHz
Relative frequency (MHz)
75Cu, I=5/2c
ou
nts
Flanagan et al., PRL103, 142501 (2009)
67 69 71 73 75 77 79 81 83 850
0.5
1
1.5
2
2.5
3
3.5
Exp
I=3/2
I=5/2
Cu isotope
ma
gn
eti
c m
om
en
t (µ
N)
Flanagan et al., PRL103, 142501 (2009)
Model space: 1f5/2, 2p3/2, 2p1/2, 1g9/2 for both proton and neutron orbits, 56Ni core
Interaction: jj4b, by Brown and Lisetskiy(private communication),gs,eff=0.7*gs,free
Comparison odd magnetic moments with theory
1g9/2
40
2p3/2
1f5/2
2p1/2
40
1f5/2
2p1/2
1g9/2
2p3/2
µeff (pp3/2)
µeff (pf5/2)
N=40 N=50
gs,eff=0.7*gs,free
55 57 59 61 63 65 67 69 71 73 75 77 791.5
1.7
1.9
2.1
2.3
2.5
2.7
2.9
3.1
3.3
odd-Cu magnetic moments
jj4b
GXPF1
experimental
isotope
Mag
net
ic m
omen
t (µ
N)
Comparison with theoretical calculations
jj4b
2p3/2
40
1f5/2
2p1/2
1g9/2
281f7/2
28
40
A. Brown, A. Listetskiy, private comm.
GXPF1
2p3/2
40
1f5/2
2p1/2
1g9/2
281f7/2
28
40
Honma et al., private comm.
N=40
µeff(pp3/2)
3/2-
Cocolios et al., PRL 2009Flanagan et al., PRL 2009
N=28
69Cu 69Cugs,eff=0.7*gs,freegs,eff=0.9*gs,free
N=50
gs,eff=0.7*gs,free
odd-Cu quadrupole moments
-0,3
-0,25
-0,2
-0,15
-0,1
-0,05
55 57 59 61 63 65 67 69 71 73 75
isotope
Qua
drup
ole
Mom
ent(
b)
GXPF1
exp
jj4b
Comparison with theoretical calculations
- Jj4b is doing a fair job in reproducing the trend- Again N=40 behaves more or less like a magic shell closure- No sign of increased deformation after N=40
N=40
3/2-
Jj4b: ep=2, en=1GXPF1: ep=1.15, en =0.8
Du Rietz et al., PRL 2004
Conclusions and Outlook
• The copper isotopes 61Cu - 75Cu have been measured at COLLAPS, ISOLDE. During the 2008 experiment 11 different isotopes were measured.
• Background reduction of 103 and more due to the RFQ beam cooler/buncher allows measurements on more exotic isotopes.
• The spin of 72Cu presents a challenge for shell model calculations
• N=40 exhibits magic properties for the magnetic and quadrupole moments thanks to parity considerations
• Quadrupole moments reveal no sign of increased deformation after N=40
Outlook
Conclusions
• 9 shifts of beamtime on neutron-deficient Cu isotopes
1Instituut voor kern-en stralingsfysica, K.U. Leuven, Belgium2IPN Orsay Cedex, France.3Schuster Laboratory, The University of Manchester, UK.4Institut fur Physik, Universität Mainz,Germany5Max-Planck-Institut für Kernphysik,Heidelberg, Germany6School of Physics and Astronomy, The University of Birmingham, UK7GSI, Darmstadt, Germany8VSM, K.U. Leuven, Belgium9ISOLDE, CERN, Geneva, Switzerland10 Institut für Kernchemie, Universität Mainz, Germany
11Department of Physics, New York University, USA
P. Vingerhoets1, K.T. Flanagan1,2, M.Avgoulea1, J. Billowes3, M.L.Bissell1, K.Blaum4,5, P.Campbell3,B.Cheal3, M. De Rydt1, D.Forrest6, C. Geppert7, P.Lievens8,
M.Kowalska9, J. Krämer4, A.Krieger4, E.Mane3, R. Neugart4, G. Neyens1, W.Nörtershäuser10, G.Ory1, A. Smolkowska1, G.Tungate6, M. Schug4, H. Stroke11, D.Yordanov4
The Collaboration
THANK YOU !
( 1) ( 1)( )
2 ( 1)p p p p n nn n
p n p n
j j j jII
j j j j I I
Evolution of the 1+ magnetic moments
60 62 64 66 68 70 72-1
-0.5
0
0.5
1
1.5
2
2.5
3
Cu isotope
mexp
memp(pp3/2np1/2)
memp(pp3/2nf5/2)
N=40
mag
net
ic m
om
ent
(µN)
1+
2p3/2
1g9/2
40
2p3/2
1f5/2
2p1/2
40
1f5/2
2p1/2
1g9/2
68Cu
For 68Cu: µp=µ(69Cu)µn=µ(67Ni)
Assume weak proton-neutron coupling:
S. Franchoo et al., Phys.Rev. C 64,054308 (2001)I. Stefanescu et al., Phys.Rev.Lett. 100, 112502 (2008)I. Stefanescu et al., Phys.Rev. C 79, 044325 (2009)B.A. Brown and A.F. Lisetskiy, private comm.
15
(m pf5/2 ng9/23; 2-) write as a function of (m pf5/2) and (m ng9/2
3; 9/2+) using additivity
I(I+1) m (I) = I ½( + ) + ½( - ) j1
m1
j2
m2
j1
m1
j2
m2j1(j1+1) j2(j2+1)-
Schmidt value exp. value (ADNDT, Stone)
(m pf5/2) = m1 +0.86 +1.58(16) 69As, Z=33, 5/2-
+1.674(2) 71As +1.63(10) 73As
(m ng9/23; 9/2+)= (m ng9/2) = m2 -1.91 (-) 1.097(9) 67Zn, N=37, 9/2+
(-) 1.157(2) 69Zn, N=39 (-) 1.052(6) 71Zn, N=41
mfree(2-) = 2 [ 0.5 (0.86/2.5 –1.91/4.5) + 0.5 (0.86/2.5 +1.91/4.5)(35/4-99/4)/6 ] = 2 [ 0.5 (-0.08) + 0.5 (0.77)(-16)/6 ]= 2 [ -0.04 – 1.027]
mfree(2-) = -2.13 mN
memp (2-) = 2 [ 0.5 (1.63/2.5 –1.05/4.5) + 0.5 (1.63/2.5 +1.05/4.5)(35/4-99/4)/6 ] = 2 [ 0.5 (+0.42) + 0.5 (0.885)(-16)/6 ]= 2 [ 0.21 – 1.18]
memp (2-) = -1.94 mN
16
(m pp3/2 np1/2-1g9/2
4; 2+) write as function of (m pp3/2) and (m pp1/2-1)
Schmidt value exp. value (ADNDT, Stone)
(m pp3/2) = m1 3.79 +2.5135(8) 67Cu, Z=29, 3/2-
+2.8372(9) 69Cu +2.28(3) 71Cu
(m np1/2-1) = m2 0.64 0.601(5) 67Ni, N=39, ½-
mfree(2+) = 2 [ 0.5 (3.79/1.5 + 0.64/0.5) + 0.5 (3.79/1.5 - 0.64/0.5) (15/4-3/4)/6 ] = 2 [ 0.5 (3.81) + 0.5 (1.25) 3/6 ]= 2 [ 1.91 + 0.31]
mfree(2+) = +4.44 mN
memp (2+) = 2 [ 0.5 (2.28/1.5 + 0.6/0.5) + 0.5 (2.28/1.5 - 0.6/0.5) (15/4-3/4)/6 ] = 2 [ 0.5 (2.72) + 0.5 (0.32) 3/6 ]= 2 [ 1.36+0.08]
memp (2+) = +1.44 mN
59 61 63 65 67 69 71 73 75 77
-0.6000
-0.4000
-0.2000
0.0000
0.2000
0.4000
0.6000
0.8000
1.0000
1.2000
1.4000
charge radii Cu
isotope
<del
ta r
^2>
Quadrupole moments vs B(E2) values
Mass number
No
rmal
ized
Q-m
om
ent
and
B(E
2) v
alu
es
Stefanescu et al, Phys.Rev.Lett. 2008
59 61 63 65 67 69 71 73 75 77
-0.6000
-0.4000
-0.2000
0.0000
0.2000
0.4000
0.6000
0.8000
1.0000
1.2000
1.4000
odd charge radii Cu
isotope
<del
ta r
^2>
59 61 63 65 67 69 71 73 75 77
-0.6000
-0.4000
-0.2000
0.0000
0.2000
0.4000
0.6000
0.8000
1.0000
1.2000
1.4000
even charge radii Cu
isotope
<del
ta r
^2>
56 58 60 62 64 66 68 70 72-1.5
-1
-0.5
0
0.5
1
1.5
2
2.5
3
Even Cu magnetic moments
experiment
GXPF1
jun/45
GXPF1A
isotope
Mag
net
ic m
omen
t (µ
N)
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