Research programs at RIKEN RIBF UENO, Hideki RIKEN Nishina Center - PDF document

Research programs at RIKEN RIBF UENO, Hideki RIKEN Nishina Center JCNP2015, RCNP, November 7-12, 2015 RIBF key experimental devices SAMURAI - large acceptance SCRIT - e-RI collision RIPS GARIS 1 & 2 - spin-oriented - SHE researches Rare RI Ring - mass medium-E RIBs ZeroDegree - γ spectroscopy CRIB - low-E RIBs RILAC2 RILAC AVF SRC RRC fRC IRC KISS SHARAQ - high resolution - KEK Isotope separator SLOWRI - slow RIBs BigRIPS - RIB production

RIBF key experimental devices SAMURAI - large acceptance ① Variable-energy mode ( E/A = 250 ~ 345 MeV) SCRIT - e-RI collision RIPS GARIS 1 & 2 - spin-oriented - SHE researches RILAC Rare RI Ring - mass BigRIPS medium-E RIBs RILAC2 ZeroDegree RRC SRC - γ spectroscopy fRC IRC CRIB AVF - low-E RIBs A X = 238 U, Xe, Kr ② Fixed-energy mode ( E/A = 345 MeV) RILAC RILAC2 RILAC BigRIPS RILAC2 AVF RRC SRC fRC IRC SRC AVF A X ≲ 18 O RRC fRC ③ AVF-injection mode ( E/A ~ 250 MeV) RILAC IRC BigRIPS RILAC2 KISS SHARAQ - high resolution RRC SRC - KEK Isotope separator SLOWRI - slow RIBs fRC IRC AVF BigRIPS - RIB production ① BigRIPS (standalone mode) Self Confining RI Ion Target RIBF Layout 150 MeV e-Microtron 700 MeV e-Storage ring High-energy branches BigRIPS - RIB production

σ R measurements M. Takechi et al ., M. Takechi et al ., Phys. Rev. C 90, 061305(R) (2014) ‒ 37 Mg Phys. Lett. B707, 357 (2012) ‒ 29, 31 Ne PF-reaction-induced spin-aligned RI beams (1) Q ( 43m S) measurement (2) New method for high spin alignment structure of N ～ 28 nuclei Two-step PF + dispersion matching R. Chevrier et al ., Phys. Rev. Lett. 108, 162501 (2012) Y. Ichikawa et al ., Nature Phys. 8 , 918 (2012) A RI A Beam A Beam A RI A RI +1 Target Slit 2 nd Target Slit 1 st Target ① μ exp (GANIL) → I π = 7/2 ‒ → I π inversion Y 320 keV 7/2 ‒ ② Q exp (RIBF) A 415 ns → moderate 7/2 ‒ deformation → strong GS deformation? Disp. （ 3/2 ‒ ) matching GS The same A can be collected ! 43 S 16 27 ① Two-step PF: → Maximize A Q exp = 23(3) e fm 2 ② Disp. Match → Maximize Y of two-step PF

Key devices Key devices in RIBF new facility area in old facility area High-energy ZeroDegree branches 3 different SHARAQ (U. Tokyo) （ E/A = 200~345 MeV) Spectrometers SAMURAI Rare RI Ring RIPS Low (Medium)-energy branches Biology (primary-beam use) ( E/A ~ 100 MeV) SLOWRI GARIS 1& 2 ( E/A ≤ 10 MeV) CRIB (U. Tokyo) SCRIT KISS (KEK) in-flight reaction-based nuclear-physics studies In-beam γ -ray spectroscopy Missing-mass spectroscopy projectile excitation. High-resolution. de-exicitaiton γrays. Excitation functions. RI beam RI beam ZeroDegree Selective excitation with Δ S , Δ L , Δ T Invariant-mass spectroscopy RI beam SHARAQ unbound states. SAMURAI particle correlations.

② BigRIPS + ZD (+DALI2) particle ID / momentum analysis Self Confining RI Ion Target e.g. Doppler shifted γ -ray measurements RIBF Layout with identification of products 150 MeV e-Microtron ZeroDegree - γ spectroscopy 700 MeV e-Storage ring High-energy branches In-beam γ -ray spectroscopy (1) P. Doornenbal, H. Wang, N. Aoi et al ., H. Scheit et al ., S. Takeuchi et al ., PRC 88, 054318 (2013) PRL 103, 032501 (2009) PRL 109, 182501 (2012) DALI2 NaI array

In-beam γ -ray spectroscopy (2) D. Steppenbeck et al ., D. Steppenbeck et al ., PRL. 114, 252501 (2015) – 50 Ar Nature (London) 502, 207 (2013). – 54 Ca N = 32 N = 34 neutron removal reactions p- wave neutron halo of 37 Mg ν s 1 / 2 ground-state properties of 20 C and 22 C 19 C+C → 18 C 20 C+C → 19 C 20 C+C → 18 C 22 C+C → 20 C N. Kobayashi et al ., PRC 86, 054604 (2012) ‒ 20,22 C T. Nakamura et al ., PRL 112, 142501 (2014) ‒ 31 Ne Press release paper N. Kobayashi et al ., PRL 112, 242501 (2014) ‒ 37 Mg

MINOS : Magic Numbers Off Stability In-beam knockout experiments Position sensitive detector: X,Y Drift time: Z beam-axis direction proton e - cathode +6000V Vertex resolution : < 5 mm FWHM Detection efficiency > 85% proton A. Obertelli et al., Eur. Phys. Jour. A 50 , 8 (2014) http://minos.cea.fr 17/11/2015 Hosted in the Spin-Isospin Laboratory at the RIKEN Nishina Center ( T. Uesaka ’ s lab) DALI2-MINOS setup • MINOS is a new detector to be used at the RIKEN RIBF Thick liquid hydrogen target and vertex tracker. First of its kind . DALI2 • Unique advantages : 1) High luminosity 2) Improved resolution 3) Clean reaction probe for knockout MINOS An exciting physics program at the RIBF has started: • Origin of di-neutron correlations in halo nuclei • Three-body forces and continuum : binding energy of Oxygen isotopes Shell evolution and search for 2 + states in neutron rich nuclei (SEASTAR) • -- First spectroscopy of 66 Cr, 72 Fe and 78 Ni recently measured – http://minos.cea.fr 17/11/2015 14

BigRIPS + MINOS C. Santamaria et al ., PRL 115, 192501 (2015) – 66 Cr, 70, 72 Fe ③ BigRIPS + ZD + EURICA Self Confining RI Ion Target RIBF Layout 150 MeV e-Microtron ZeroDegree - γ spectroscopy 700 MeV e-Storage ring High-energy branches EU roball R ien C luster A rray

③ BigRIPS + ZD + EURICA Project manager: S. Nishimura EUroball Riken Cluster Array (EURICA) project • Commenced since 2012 spring • Gamma-ray detector clusters - 84 high-purity germanium crystals in 12 clusters - High resolution ( ~ 2.5 keV @ 1.3 MeV ) - High efficiency ( ~ 13% @ 1 MeV ) - High granularity ( 84 crystals ) • Double-side-stripped-silicon-detector stack - 8 pieces of DSSD with 60 x 40 pixels Decay Spectroscopy around A = 100 ~ 145 U-beam: 8 – 10 pnA Two EURICA data sets: G.Simpson/A.Jungclaus & H.Watanabe/G.Lorusso ~ 10 days 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..

③ BigRIPS + ZD + EURICA T 1/2 : 78 Niand neighbors 116Tc → 116Ru 118Tc → 118Ru P-A. S ӧ derst ӧ rm et al ., RC 88, 024301 (2013) Z.Y. Xu, Nishimura et al ., PRL 112, 132501 (2014) H. Watanabe et al ., PRL 111, 152501 (2013) 126, 128 Pd isomers ( N =82 magicity) p 3/2 hole state ( N =82 magicity) J. Tapprogge et al ., PRL 112, 132501 (2014) 110 Half-lives from Very Neutron-Rich Rb to Sn G.Lorusso et al., 40 new half-lives ! PRL 114, 192501 (2015)

International collaboration １ ９ countries ： ２ ３ ７ collaborators ！ J. Agramunt, P. Aguilera, T. Alharbi, A. Algora, G. Angelis, N. Aoi, P. Ascher, R. Avigo, H.Baba, C. Borcea, A. Boso, A.M. Bruce, R.B. Cakirli, F.L.Bello Garrote, G. Benzoni, J.S.Berryman, R. Berta, B. Blank, N. Blasi, A. Blazhev, P. Boutachkov, S. Bonig, A. 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. 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. Wieland, K. Wimmer, J. Wu, Q. Wu, F.R. Xu, Z.Y. Xu, A. Yagi, S. Yagi, H. Yamaguchi, K. Yamaguchi, T. Yamamoto, M. Yalcinkaya, R. Yokoyama, S. Yoshida, K. Yoshinaga, G. Zhang Acknowledgement: Gammapool Owners Committee, GSI PreSPEC, RISP BRIKEN Project (RIBF) 3He Detectors + Silicon Strip detectors (AIDA) Very high efficiency neutron detector  Survey of beta-delayed multi-neutron & T1/2