Decay spectroscopy around 68Ni with the EURICA setup
G.Benzoni
INFN sezione di Milano, Italy

Outline:• Motivations• Exp. Details• First results

1-6 June ARIS 2014 Tokyo

Physics around 68Ni

* Monte Carlo shell-model calculations
give a coherent description of theexperimental results and suggest thatspherical, oblate, and prolate shapes
appear within the energy range of 3 MeV
in 68Ni.
*Discussion in the conference about 68Ni
Topical talks+ POSTERS PS2-1037 Tsunoda
PS2-A039 Suchyta

Suchyta et al., PRC89 (2014) 021301(R)
Y.Tsunoda et al.,Phys.Rev. C 89 (2014) 031301

1-6 June ARIS 2014 Tokyo

Physics around 68Ni
68Ni is not a closed core

* rapid drop of 2+ energy in Fe and Cr chains* B(E2) indicate an increase in collectivity

Are 70-72Fe deformed?

Ni

Onset of collectivity as protons are removed from f7/2
along the N=40 isotonic chain

Cr Removal of 2 protons from 68Ni to 66Fe results in aninversion of the normal configuration
The presence of intruder levels have been observedin the odd-A 65,67Co isotopes where proton
excitations across the Z = 28 shell have beensuggested to account for the anomalous low-energy
1/2− states in both 65,67Co

CrFeFeNiPauwels et al. PRC78, 041307(R)(2010)

A. Macchiavelli, Acta Phys. Pol. B 44, 359 (2013).
B. Pritychenko et al.At. Data Nucl. Data Tables
98, 798 (2012).
T. Baugher et al, Phys. Rev. C 86, 011305 (2012).
B.Olaizola et al, PRC88(2013) 044306

1-6 June ARIS 2014 Tokyo3

Fe isotopes: up-to-date experimental information
Region has been attached by many exp. lately(MSU-CERN)- Fast timing measurements 63Mn->63Fe
65Mn->65Fe
66Mn->66Fe
POSTERS: PS1-A011
PS1-A012
B.Olaizola et al, PRC88(2013) 044306
67Mn-> 67Fe

68Mn->68Fe

68Mn->68Fe

S.N.Liddick et al., PRC 87, 014325 (2013).

J.M.Daugas et al., PRC 83, 054312 (2011).

RIBF80+RIBF49 experiment at RIKEN
3 days of beamtime
238U @ 345MeV/u
Ibeam~ 10 pnA
BigRIPS setting focused on 71Fe
Decay +In-Beam studies

In-beam
Coulex 73-75Ni

DALI2

BigRIPS setting:
3mm Be target
5.92 mm Al F1 degrader
4.42 mm Al F5 degrader
1 g/cm2 Pb secondary target

EURICA setup5 DSSSD - WAS3ABI(64X40 strips)
Ion-beta correlations

12 HPGe Clusters
b-g correlations

18 LaBr3(Ce) (1.5”x 2”)
2 BC-418 Plastic 2mm thickFast-timing measurements

1-6 June ARIS 2014 Tokyo

Experimental spectra

NiCoFeMn

Research mainly focusing in:• Isomer search• New half-lives• Delayed spectroscopy:• Transitions measured for first time
• Extension of level schemes

Example of implantation
profiles for 72Co

total

73Ni

74Ni

1-6 June ARIS 2014 Tokyo75Ni

Lifetime measurement
ParentNions

ebT1/2[ms]70Co

1.5 ·10532

112.3(2.6)

71Co

1.6·10648

86.5(0.3)

72Co

106

5453.6(0.2)

73Co

3·105

52

41.9(0.2)

74Co

3·104

52

33.5(0.5)

75Co

104

56

25.9(2.1)

69Fe

2·105

34107.4(1)70Fe

1.8·10551

65.9(0.5)

71Fe

3·104

48

31.9(0.6)

72Fe

5.4·10353

14.7(0.9)

73Fe

300

53

13.3(1.6)

68Mn-> 68Fe

69Mn-> 69Fe

Ref

FRDM [3]68Mn

7.7·1034634.92(10)40(7) [1]

12.8

69Mn

5·103

4322.20(9)18(4) [2]

12.9

70Mn

500

57

12.4(4)

9[1] S.N.Liddick et al., PRC 87, 014325 (2013).
[2] J.M.Daugas et al., PRC 83, 054312 (2011)[3] P.Moller, B.Pfeiffer and K.-L. Kratz,Phys.Rev. C 67, 055802 (2003)

1-6 June ARIS 2014 Tokyo68Mn-> 68Fe

b-n channel
Daughter decay

2843

S.N.Liddick et al., PRC 87, 014325 (2013).

Agreement with latest results
Additional state at 2.8 MeV
decaying to 2+

1-6 June ARIS 2014 Tokyo69Mn-> 69Feand 70Mn-> 70Fe

b-n channel
daughter decay

Decay spectra of 69-70Fe• Definition of the level scheme• Pn evaluation• Comparison with SM calculations (S.Lenzi)

1-6 June ARIS 2014 Tokyo

Conclusions:• Region around 68Ni studied at RIKEN• Relativistic fission of 238U beam
• BigRIPS+ZeroDegree + EURICA setup* 3 days of beamtime* Populated wanted region with sufficient statistics* Results still VERY preliminary Measurement of new half-lives
 Transitions in 69-70Mn measured for first time Evaluation of other populated nuclei (Co-Ni)

738

74Co->74Ni

1-6 June ARIS 2014 Tokyo

C.Mazzocchi et al. PLB622

Collaboration
Ana Isabel Morales Lopez INFN-MILANOHiroshi WATANABE Beihang UnivNISHIMURA Shunji RIKEN
LORUSSO Giuseppe RIKENSUMIKAMA Toshiyuki Tohoku Univ.
DOORNENBAL Pieter RIKENMelon Barbara
XU Zhengyu Univ. of Tokyo/RIKENISOBE Tada-aki RIKENSöDERSTRöM P.A. RIKEN
BROWNE Frank Brighton Univ./IPA
WU Jin Peking Univ./RIKENYAGI Ayumi Osaka Univ.
BABA Hidetada RIKENPATEL Zena Surrey Univ./IPA
RICE Simon Surrey Univ./IPA
SINCLAIR Laura York Univ./IPA

DOMBRADI Zsolt ATOMKI
SOHLER Dora ATOMKIVAJTA Zsolt ATOMKI
KUTI Istvan ATOMKI
INFN-Firenze
Valiente Dobon Jose Javier INFN-LNL
Mengoni Daniele Universita' di Padova
Modamio Hoybjor Victor INFN-LNL
Napoli Daniel INFN-LNL
Yalcinkaya Mehtap University of Istanbul
Sahin Eda Univ. of Oslo
Sakurai Hiroyoshi Univ. of Tokyo
Taniuchi Ryo Univ. of Tokyo/RIKEN
Matsui Keishi Univ. of Tokyo
Miyazaki Takuya Univ. of Tokyo
Momiyama Satoru Univ. of Tokyo
Orlandi Riccardo Instituut voor Kern- en
StralingsFysica/K.U. Leuven
Delattre Marie-Coralie IPNO Orasy

Crespi Fabio C.L. INFN-MilanoBlasi Nives INFN-MilanoCeruti Simone INFN-MilanoAvigo Riccardo INFN-Milano
YOKOYAMA Rin CNS
DAIDO Rie Osaka Univ.
FANG Yifan Osaka Univ.
NIIKURA Megumi Univ. of TokyoWIELAND Oliver INFN-Milano
TAPROGGE Jan Consejo Superior de Investigaciones Cientificas
BELLO GARROTE Frank L. Univ. of Oslo
DE ANGELIS Giacomo INFN-LNL
GOTTARDO Andrea INFN-LNL

1-6 June ARIS 2014 Tokyo