Decay spectroscopy at RIBF: The EURICA project and its impact on nuclear structure and astrophysics ISOLDE Workshop and Users meeting 2015 2 nd – 4 th , December, 2015 Department of Physics and Astronomy, KU Leuven RI Physics Lab., RIKEN Nishina Center Zhengyu Xu for the EURICA Collaboration
Table of Content What is EURICA? Motivation and experimental setup Highlights of experimental results Summary and perspective
What is EURICA? Euroball Riken Cluster Array High efficiency gamma-ray detector array + Highly segmented Si stopper / passive stopper + High beam intensity at RIBF (10 pnA 238 U or 30 pnA 124 Xe) Isomer and b -decay spectroscopy!
Decay properties of exotic nuclei studied with EURICA Beta-decay half lives, Beta- delayed neutron-emission probabilities of exotic nuclei. Maandag - vrijdag: 10u00 - 12u30 en 13u30 - 17u00 - New magic number ? Weekdagen na 17u00 op afspraak - Shell quenching? - Single particle levels? Zaterdag op afspraak - Deformation?
General experimental setup of an EURICA campaign Cluster Ge-detectors (gamma-ray detection) Cluster Ge-detectors (gamma-ray detection) Beta-counting system inside EURICA EURICA m m a a e e B B I I R R gamma-ray Identification of RI WAS3ABi ： beta-ray detection WAS3ABi ： beta-ray detection 238U (124Xe) Beam Separation of RI RI Beam Production Target
Decay spectroscopy with the “old” cluster detectors EURICA@RIKEN 2012-2015 RISING@GSI 2006-2009
WAS 3 ABi (Wide-range Active Silicon Strip Stopper for beta and ions) Collaboration RIKEN / TUM / IBS ● 8 DSSD 1-mm thick ● 80 keV threshods ● 20 keV energy resolution ● 100 - 200 pps Maximum rate ● Q value capability ● About 20000 pixels
General experimental setup of an EURICA campaign LaBr 3 (Ce) (fast timing) EURICA Passive stopper Identification Different stopper/detectors of RI can be employed to meet the requirements of specific experiments. Separation of RI Production Target
EURICA Collaboration International collaboration 19 countries ： 238 collaborators ！ J. Agramunt, P. Aguilera, T. Alharbi, A. Algora, G. Angelis, N. Aoi, P. Ascher, R. Avigo, 2013 H.Baba, C. Borcea, A. Boso, A.M. Bruce, R.B. Cakirli, F.L.Bello Garrote, G. Benzoni, 2012 238 U J.S.Berryman, R. Berta, B. Blank, N. Blasi, A. Blazhev, P. Boutachkov, S. Bonig, A. 124 Xe Bracco, F. Browne, F. Camera, R.J. Carroll, S. Ceruti, I. Celikovic, K.Y. Chae, J. Chiba, L. Coraggio, A. Covello, F.C.L. Crespi, J.-M. Daugaus, R. Daido, P. Davis, M.C. Delattre, F. Diel, F. Didiejean, Zs. Dombradi, P. Doornenbal, F. Drouet, H.J. Eberth, A. Estrade, Y. Fang, T. Faestermann, G. France, S. Franchoo, Y. Fujita, N. Fukuda, A. Gadea, E. Ganioglu, A. Gargano, W. Gelletly, M. Gerbaux, R. Gernhauser, G. Gey, J. Giovninazzo, S. Go, N. Goel, T. Goigoux, M. Gorska, A. Gottardo, H. Grawe, S. Grevy, C. Griffin, Vi. Guadilla, T. Hashimoto, S. Hayakawa, J. Henderson, C. Hinke, N. Hinohara, E. Ideguchi, S. Ilieva, N. Inabe, T. Ishigaki, T. Isobe, Y. Ito, D.G. Jenkins, P.R. John, H.S. Jung, A. Jungclaus, T. Kajino, D. Kameda, H. Kanaoka, Y. Kanke, Y. Kawada, G.D. Kim, Y.-K. Kim, G. Kiss, Ka. Kobayashi, K. Kobayashi, M. Kobayashi, N. Kobayashi, K. Koehler, I. Kojouharov, T. Komatsubara, F.G. Kondev, Z. Korkulu, Y. Kondo, M. Kowalska, T. Kroll, R. Krucken, T. Kubo, S. Kubono, M. Kurata-Nishimura, T. Kurtukian Nieto, N. Kurz, I. Kuti, Y.K. Kwon, G.J. Lane, S. Lalkovski, G. Lane, E. Lee, J. Lee, P. Lee, S. Lenzi, M. Lewitowicz, Z. Li, J. Liu, T. Lokotko, G. Lorusso, G. Lotay, R. Lozeva, D. Lubos, C. Magron, F. Molina, I. Matea, K. Matsui, M. Matsushita, B. Melon, D. Mengoni, B. Meyer, S. Michimasa, T. Miyazaki, V. Modamio Hoybjor, S. Momiyama, C.- B. Moon, A. Morales. A. Montaner-Piza, A.I. Morales, P. Morfouace, S. Morimoto, K. Moschner, D. Mucher, E. Nacher, J. Nagumo, H. Naidja, T. Nakao, T. Nakatsukasa, D.R. Napoli, F, Naquvi, M. Niikura, H. Nishibata, S. Nishimura, I. Nishizuka, C. Nita, F. Nowacki, A. Odahara, K. Ogawa, H. Oikawa, R. Orlandi, S. Ota, T. Otsuka, H.J. Ong, S. Orrigo, M. Rajabali, J. Park, Z. Patel, A. Petrovici, F. Recchia, V. Phong, Zs. Podolyak, O.J. Roverts, L. Prochniak, P.H. Regan, S. Rice, E. Sahin, H. Sakurai, K. Sato, H. Schaffner, H.Scheit, P. Schury, C. Shand, Y. Shi, S. Shibagaki, T. Shimoda, Y. Shimizu, K. Sieja, L. Sinclair, G.S. Simpson, P.-A. Soderstrom, D. Sohler, I.G. Stefan, K. Steiger, D. Steppenbeck, K. Sugimoto, T. Sumikama, D. Suzuki, H. Suzuki, T. Tachibana, K. Tajiri, S. Takano, A. Tashima, H. Takeda, Man. Tanaka, Mas. Tanaka, Y. Takei, R. Taniuchi, J. Taprogge, K. Tajiri, T. Teranishi, S. Terashima, G. Thiamova, K. Tshoo, Zs. Vajta, J. Valiente Dobon, Y. Wakabayashi, P.M. Walker, H. Watanabe, A. Wendt, V. Werner, O. 2012 Wieland, K. Wimmer, J. Wu, Q. Wu, F.R. Xu, Z.Y. Xu, A. Yagi, S. Yagi, H. Yamaguchi, 238 U K. Yamaguchi, T. Yamamoto, M. Yalcinkaya, R. Yokoyama, S. Yoshida, K. Yoshinaga, G. Zhang
EURICA Campaigns 2012-2015 J.Jin Half-lives (T 1/2 ) J.Wu Isomer (T 1/2 ) G.Zhang P.A.S ö derstr ö m Beta-delayed gamma H.Watanabe Beta-delayed n, p EC, Q b , New isotopes Z.Patel G.Simpson E.Ideguchi, M.Tanaka I.Celikovic R.Yokoyama P.Boutachkov D.Lubos M.Lewitwicz W.Jin K.M ö schner J.Park S.Nishimura R.Gernh ä user A.Odahara A.Yagi G.Lorusso R.Lozeva H.Suzuki P.S.Lee, C.B.Moon L.Sinclair A.Jungclaus G.Simpson P.Davies B.Blank G.Lorusso Z.Li Y.Shimizu G.Gey B.Rubio, T.Fujita, .. F.Naqvi H.S.Jung A.Algora, . P.-A.Söderström V.Warner T.Sumikama . G.Lorusso G.Benzoni M.Niikura E.Sahin T.Sumikama H.Watanabe Z.Y.Xu F.Browne Orsay Gr. I.Nishizuka P.A.S ö derstr ö m F.Bello D.Sohler, Z.Vajta
Experimental results in the region N =40 ~ 50
Beta-decay half-lives beyond 78 Ni Decay curve of 79 Ni Shorter T 1/2 beyond 78 Ni: Pronounced in Z = 28, N=50 Shorter T 1/2 beyond 78 Ni: Pronounced in Z = 28, N=50 78 Ni is a double magic nucleus !? 78 Ni is a double magic nucleus !? 78 Ni 79 Ni 77 Co Z.Y.Xu, S.Nishimura, G.Lorusso et al ., PRL 113, 032505 (2014)
Studying the collectivity up to N =44 in the Fe chain 68 Fe 69 Fe 70 Fe From 400 ions of 70 Mn It is found that the experimental R 4/2 ratio is properly reproduced for A >36 by the shell model only with the inclusion of the 1d 5/2 neutron orbital in the valence space. This is interpreted, as for Cr isotopes, in terms of the interplay between the quadrupole correlations of the ν1d 5/2 and ν0g 9/2 orbitals and the monopole component of the π0f 7/2 - ν0f 5/2 interaction, thus driving the deformation in the neutron-rich Cr-Fe region. G.Benzoni et al ., PLB 751, 107 (2015)
Experimental results in the region N =60 ~ 82
The seniority isomers in the N =82 isotones Delayed coin. with 128 Pd ions (Δt=0.15-25 μs) γ-γ coincidence with a gate on 1311 keV B(E2;8 + →6 + ) B(E2;8 + →6 + ) 2 Seniority (ν) scheme 2 j 1 2 n Seniority (ν) scheme 2 B ( E 2 ; J J 2 ) e eff 2 j 1 2 A.Jungclaus et al ., PRL 99, 132501 (2007) 128 Pd 82 130 Cd 82 H. Watanabe et al ., PRL111, 152501 (2013) Robust shell closure at N=82 Robust shell closure at N=82 Good ν=2 in the well isolated πg 9/2 subshell Good ν=2 in the well isolated πg 9/2 subshell
2 J π =6 + seniority isomers in 136, 138 Sn ν f 7/2 The excited states up to 6+ ~640 ns flight time BigRIPS 875,000 ions of 136,138 Sn were constructed C per 12.4 ns 40 T 1/2 =46(7) ns via the isomeric decay 136 Sn 80 a) T 1/2 =46(7) ns spectra. The knowledge of 20 391 the excitation energies of the 60 0 first 2+ states was extended 0 50 100 150 200 250 Counts Time (ns) to 138 Sn. 40 688 216 20 134 Sn 136 Sn 138 Sn 0 16 C per 100 ns 20 T 1/2 =210(45) ns 138 Sn b) T 1/2 =210(45) ns 14 10 168 12 0 10 0 250 500 750 1000 Counts Time (ns) 461 8 715 6 4 2 0 100 200 300 400 500 600 700 800 900 Energy (keV) 5,000 ions The life time of the 136 Sn isomer is very short!! The experimental B(E2; 6+ → 4+) rate of 136 Sn can be reproduced by reducing the neutron pairing strength by ~150 keV, with the result that the first 4+ state now has mixed seniority (46% ν = 2, 55% ν=4). G. S. Simpson et al ., PRL 113, 132502 (2014)
Identification of a proton single-hole state in 132 Sn 60 988 keV 132 Cd Counts/2 keV 40 20 0 600 @ 131 Cd x4 Counts/2 keV # 400 200 & # 0 0 1000 2000 3000 4000 5000 6000 Energy (keV) N=50 N=82 realistic SM empirical SM H. Grawe, A. Gargano A.F. Lisetskiy New p p 3/2 single-hole energy in 132 Sn ! p p 3/2 -1 p p 1/2 -1 No proton subshell p g 9/2 -1 structure ! J. Taprogge, A. Jungclaus et al ., PRL 112, 132501 (2014)
Beta-decay half-lives around A = 100~145 U-beam: 8 – 10 pnA Two EURICA data sets: G.Simpson/A.Jungclaus & H.Watanabe/G.Lorusso ~ Two weeks Known T 1/2 New Isotopes 144 Te 140 Sb 139,140 Sn 136,137 In 134,135 Cd 131,132 Ag 129,130 Pd 127 Rh 120,121 Tc 118 Mo and more..
Beta-decay half-lives around A = 100~145 U-beam: 8 – 10 pnA Two EURICA data sets: G.Simpson/A.Jungclaus & H.Watanabe/G.Lorusso ~ Two weeks Known T 1/2 New Isotopes 144 Te 140 Sb 40 new half lives!! 139,140 Sn 136,137 In 134,135 Cd 131,132 Ag 129,130 Pd 127 Rh 120,121 Tc 118 Mo and more.. G.Lorusso et al ., PRL 114, 192501 (2015)
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