A systematic study of - decay of neutron-rich Rh and Ag isotopes

Sixth China Japan Joint Nuclear Physics Symposium

Shanghai, May 16-20, 2006

Youbao Wang

Collaborators and publicationsCollaborators: Youbao Wang, S. Rinta-Antila, P. Dendooven, J. Huikari, A. Jokinen, V. S. Kolhinen, G. Lhersonneau, A. Nieminen, S. Nummela, H. Penttilä, K. Peräjärvi, J. Szerypo, J. C. Wang, and J. Äystö

Department of Physics, University of Jyväskylä, FINLAND

1. New Levels in 118Pd Observed in the Decay of very Neutron-Rich 118Rh Isotope Chin. Phys. Lett. 23(4), 808(2006)

2. decay of neutron-rich 118Ag and 120Ag isotopes Phys. Rev. C 67, 064303 (2003)

3. Decay of 114Rh to 114Pd Phys. Rev. C 67, 024303 (2003)

4. decay of 116Agm and the vibrational structure of 116Cd Phys. Rev. C 64, 054315 (2001)  

5. Beta decay of neutron-rich 116Rh and the low-lying level structure of even-even 116Pd Phys. Rev. C 63, 024309 (2001)

JYFL Layout

Transmission: 50 %, M/M=10 (with gas, 1mbar of Helium gas)

M/M=100 (in vacuum mode)

Recoil Ion Transport Unit

IGISOL-Ion Guide Isotope Separator On Line

Ion TrapIon Cooler

Magnet

Beam Stop

Ion Guide

Cyclotron beam

The Principle of Ion Guide

Main ion guide characteristics

• fast (ms separation times)

• no element selectivity

• large beam energy spread (~100 eV)

Fission ion guide

0 5 cm

extraction electrode

cyclotron beam

helium inlet

target

target chamber

stopping chamber

nozzle

skimmer

chamber separation

foil

Partial Nuclide Chart

46

48

116In 118In 120In 122In

66

68

70

72

74

124Sn

44 110Ru 112Ru 114Ru 116Ru 118Ru

124In

112Rh 114Rh 116Rh118Rh0.31s

120Rh

112Pd 114Pd 116Pd 118Pd 120Pd 122Pd

126In 128In

76

78 80

114Ag 116Ag 118Ag 120Ag 122Ag 124Ag 126Ag

114Cd 116Cd 118Cd 120Cd 122Cd 124Cd 126Cd 130Cd128Cd

50

116Sn 118Sn 120Sn 122Sn 126Sn 128Sn

130In

132Sn130Sn

82

110Tc 112Tc 114Tc

42 108Mo 110Mo 112Mo

132In

134Sn

84128Ag58ms

68ms

132Cd97ms

N

Z

Level Systematics for Ru, Pd, and Cd IsotopesLevel Systematics for Ru, Pd, and Cd Isotopes

56 60 64 68 72 76 80100

200

300

400

500

600

700

800

(a)

E(2

+ ) (ke

V)

Neutron number

48

Cd 46

Pd 44

Ru

56 60 64 68 72 76 802.1

2.2

2.3

2.4

2.5

2.6

2.7

2.8

2.9

(b)

E(4

+ )/E(2

+ )

Neutron number

48

Cd 46

Pd 44

Ru

j

j'

j

2p-4h intruder excitation

Collective Vibration

1

0+

3

2

2+

0+2+4+

2 2

2+4+6+ 3+ 0+

710

711

76

715

3536

74

57 3

Two isomeric decays of Rh and Ag isotopes

116Pd

116Rh

12.4 s

0.68 s-

0.57 s

-

(6-)

1+

0+

114Pd

114Rh

2.42 m

1.85 s-

1.85 s

-

(7)-

1+

0+

116Pd

116Rh

12.4 s

0.68 s-

0.57 s

-

(6-)

1+

0+

116Pd

116Rh

12.4 s

0.68 s-

0.57 s

-

(6-) 0.57 s

-

(6-)

1+

0+

114Pd

114Rh

2.42 m

1.85 s-

1.85 s

-

(7)- 1.85 s

-

(7)-

1+

0+

118Cd

118Ag

50.3 min

2.0 s

3.76 s

-

-

(4+)

(1-)

128

120Cd

120Ag

50.8 s

0.40 s

1.23 s

-

-

(6-)

(3+)

203

0+

0+

116Cd

116Ag

stable

8.2 s

2.68 m

-

-

(5+)

(2-)

81

0+

63%

54%

94%

118Cd

118Ag

50.3 min

2.0 s

3.76 s

-

-

(4+)

(1-)

128

120Cd

120Ag

50.8 s

0.40 s

1.23 s

-

-

(6-)

(3+)

203

0+

0+

116Cd

116Ag

stable

8.2 s

2.68 m

-

-

(5+)

(2-)

81

0+

63%

54%

94%

Experimental setup

moving tape

cylindrical plastic

scintillator

beam from IGISOL

• cylindrical plastic scintillator: = 63 %• 4 Ge - detectors tot= 2.4 % (1 MeV)

• tape transport system

Decay of 114Rh (1+)

Decay of 114Rh (7-) (part)

Decay of 116Rh

0.0 0.5 1.0 1.5 2.0 2.5

0

1x104

2x104

3x104

4x104

5x104

116Rhm (6 -)

T1/2

= 0.57(5) s

328 keV

Cou

nts

time (s)

Decay of very neutron-rich 118Rh

Fifteen neutrons from the stable 103Rh

Systematics of even-mass Palladium Nuclei

Systematics of two-quasineutron levels

First observation of complete set of three-phonon quintuplet!

Decay of 120Ag-- a gated spectrum

Gate: 120Cd 505.7 keV 2+0+

Decay of 120Ag (half life and intensity ratios)

Comparison of the three-phonon states

Systematics of low-spin levels in Pd nuclei

104 106 108 110 112 114 116 118 120

500

1000

1500

2000

2+

2+

0+

2+

0+

Exc

itatio

n en

ergy

(keV

)

Pd nuclei

104 106 108 110 112 114 116 118 120 122

500

1000

1500

2000

2500

3000

3500

6+

4+

2+

0+6+

4+

2+

Exci

tatio

n en

ergy

(keV

)Cd nuclei

Systematics of intruder states in Cd nuclei

Multi-phonon and intruder states in 116Cd

M. Kadi et al., PRC68, 031306(R) (2003)

Thank you!

Proton-induced fission

Collective Vibration

1

0+

3

2

2+

0+2+4+

2 2

2+4+6+ 3+ 0+

710

711

76

715

3536

74

57 3

L Formula

03+ 3E(22

+) - 3E(21+)

31+ -3E(21

+) + 6/7E(41+) + 15/7E(22

+)

42+ -3E(21

+) + 10/7E(41+) + 11/7E(22

+)

61+ 3E(41

+) - 3E(21+)

23+ -3E(21

+) + 36/35E(41+) + 4/7E(22

+)+7/5 E(02+)

Energies of the three-phonon quintuplet in terms of

the two-phonon anharmonicities

j

j'

j

50 54 58 62 66 70 74 78 820

1

2

3

4

5

6

7

Cadmium

Exc

itatio

n E

nerg

ies

(MeV

)

Neutron Number

The neutron dependence of proton 2p-2h intruder excitation energies

for Cd nuclei

2p-2h intruder