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)

56 58 60 62 64 66 68 70 72

-15.00

-10.00

-5.00

0.00

5.00

10.00

15.00

experimental

GXPF1A

jun/45

GXPF1

mass number

Qua

drup

ole

mom

ent (

efm

2)