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1. Structure of high-lying levels populated in the Y-96 -> Zr-96 beta decay

Author

Mashtakov, KR, Ponomarevc, V Yu, Scheck, M, Finch, SW, Isaak, J, Zweidinger, M, Agar, O, Bathia, C, Beck, T, Beller, J, Bowrya, M, Chapman, R, Chishti, MMR, Friman-Gayer, U, Gaffney, LP, Garrett, PE, Gregor, ET, Keatings, JM, Koster, U, Loher, B, MacLean, AD, O'Donnell, D, Pai, H, Pietralla, N, Rainovski, G, Ramdhane, M, Romig, C, Rusev, G, Savran, D, Simpson, GS, Sinclair, J, Sonnabend, K, Spagnoletti, P, Tonchev, AP, and Tornow, W

Subjects
Science & Technology, Physics, Nuclear, Reactor antineutrino anomaly, NUCLEAR-DATA SHEETS, Quasi-particle phonon model, Physics, Physical Sciences, High resolution gamma-ray spectroscopy, Pygmy dipole resonance, Astronomy & Astrophysics, Physics, Particles & Fields
Abstract

ispartof: PHYSICS LETTERS B vol:820 status: published

Published
2021

3. Detailed spectroscopy of doubly magic 132Sn

Author

Benito, J, Fraile, LM, Korgul, A, Piersa, M, Adamska, E, Andreyev, AN, Álvarez-Rodríguez, R, Barzakh, AE, Benzoni, G, Berry, T, Borge, MJG, Carmona, M, Chrysalidis, K, Costache, C, Cubiss, JG, Day Goodacre, T, De Witte, H, Fedorov, DV, Fedosseev, VN, Fernández-Martínez, G, Fijałkowska, A, Fila, M, Fynbo, H, Galaviz, D, Galve, P, García-Díez, M, Greenlees, PT, Grzywacz, R, Harkness-Brennan, LJ, Henrich, C, Huyse, M, Ibáñez, P, Illana Sison, A, Janas, Z, Jolie, J, Judson, DS, Karayonchev, V, Kicińska-Habior, M, Konki, J, Kurcewicz, J, Lazarus, I, Lică, R, López-Montes, A, Lund, M, Mach, H, Madurga, M, Marroquín, I, Marsh, B, Martínez, MC, Mazzocchi, C, Mărginean, N, Mărginean, R, Miernik, K, Mihai, C, Mihai, RE, Nácher, E, Negret, A, Olaizola, B, Page, RD, Paulauskas, SV, Pascu, S, Perea, A, Pucknell, V, Rahkila, P, Raison, C, Rapisarda, E, Régis, J-M, Rezynkina, K, Rotaru, F, Rothe, S, Sánchez-Parcerisa, D, Sánchez-Tembleque, V, Schomacker, K, Simpson, GS, Sotty, C, Stan, L, Stănoiu, M, Stryjczyk, M, Tengblad, O, Turturica, A, Udías, JM, Van Duppen, P, Vedia, V, Villa-Abaunza, A, Viñals, S, Walters, WB, Wadsworth, R, Warr, N, and IDS Collaboration

Abstract

ispartof: Physical Review C vol:102 issue:1 status: published

Published
2020

4. g Factor of the Zr-99 (7/2(+)) Isomer: Monopole Evolution in the Shape-Coexisting Region

Author

Boulay, F, Simpson, GS, Ichikawa, Y, Kisyov, S, Bucurescu, D, Takamine, A, Ahn, DS, Asahi, K, Baba, H, Balabanski, DL, Egami, T, Fujita, T, Fukuda, N, Funayama, C, Furukawa, T, Georgiev, G, Gladkov, A, Hass, M, K., Imamura, Inabe, N, Ishibashi, Y, Kawaguchi, T, Kawamura, T, Kim, W, Kobayashi, Y, Kojima, S, Kusoglu, A, Lozeva, R, Momiyama, S, Mukul, I, Niikura, M, Nishibata, H, Nishizaka, T, Odahara, A, Ohtomo, Y, Ralet, D, Sato, T, Shimizu, Y, Sumikama, T, Suzuki, H, Takeda, H, Tao, LC, Togano, Y, Tominaga, D, Ueno, H, Yamazaki, H, Yang, XF, Daugas, JM, and Parnefjord Gustafsson, Fredrik

Abstract

The gyromagnetic factor of the low-lying E=251.96(9) keV isomeric state of the nucleus ^{99}Zr was measured using the time-dependent perturbed angular distribution technique. This level is assigned a spin and parity of J^{π}=7/2^{+}, with a half-life of T_{1/2}=336(5) ns. The isomer was produced and spin aligned via the abrasion-fission of a ^{238}U primary beam at RIKEN RIBF. A magnetic moment |μ|=2.31(14)μ_{N} was deduced showing that this isomer is not single particle in nature. A comparison of the experimental values with interacting boson-fermion model IBFM-1 results shows that this state is strongly mixed with a main νd_{5/2} composition. Furthermore, it was found that monopole single-particle evolution changes significantly with the appearance of collective modes, likely due to type-II shell evolution. ispartof: Physical Review Letters vol:124 issue:11 ispartof: location:United States status: Published online

Published
2020

5. Proton Shell Evolution below Sn-132: First Measurement of Low-Lying beta-Emitting Isomers in Ag-123,Ag-325

Author

Chen, ZQ, Li, ZH, Hua, H, Watanabe, H, Yuan, CX, Zhang, SQ, Lorusso, G, Nishimura, S, Baba, H, Browne, F, Benzoni, G, Chae, KY, Crespi, FCL, Doornenbal, P, Fukuda, N, Gey, G, Gernhaeuser, R, Inabe, N, Isobe, T, Jiang, DX, Jungclaus, A, Jung, HS, Jin, Y, Kameda, D, Kim, GD, Kim, YK, Kojouharov, I, Kondev, FG, Kubo, T, Kurz, N, Kwon, YK, Li, XQ, Lou, JL, Lane, GJ, Li, CG, Luo, DW, Montaner-Piza, A, Moschner, K, Niu, CY, Naqvi, F, Niikura, M, Nishibata, H, Odahara, A, Orlandi, R, Patel, Z, Podolyak, Zs, Sumikama, T, Soderstrom, P-A, Sakurai, H, Schaffner, H, Simpson, GS, Steiger, K, Suzuki, H, Taprogge, J, Takeda, H, Vajta, Zs, Wang, HK, Wu, J, Wendt, A, Wang, CG, Wu, HY, Wang, X, Wu, CG, Xu, C, Xu, ZY, Yagi, A, Ye, YL, and Yoshinaga, K

Subjects
RIKEN, Science & Technology, IMPACT, Physics, Physical Sciences, Physics, Multidisciplinary, ISOTOPES, DECAY
Abstract

The β-delayed γ-ray spectroscopy of neutron-rich ^{123,125}Ag isotopes is investigated at the Radioactive Isotope Beam Factory of RIKEN, and the long-predicted 1/2^{-} β-emitting isomers in ^{123,125}Ag are identified for the first time. With the new experimental results, the systematic trend of energy spacing between the lowest 9/2^{+} and 1/2^{-} levels is extended in Ag isotopes up to N=78, providing a clear signal for the reduction of the Z=40 subshell gap in Ag towards N=82. Shell-model calculations with the state-of-the-art V_{MU} plus M3Y spin-orbit interaction give a satisfactory description of the low-lying states in ^{123,125}Ag. The tensor force is found to play a crucial role in the evolution of the size of the Z=40 subshell gap. The observed inversion of the single-particle levels around ^{123}Ag can be well interpreted in terms of the monopole shift of the π1g_{9/2} orbitals mainly caused by the increasing occupation of ν1h_{11/2} orbitals. ispartof: PHYSICAL REVIEW LETTERS vol:122 issue:21 ispartof: location:United States status: published

Published
2019

6. Experimental study of the lifetime and phase transition in neutron-rich 98,100,102Zr

Author

Ansari, S, Régis, J-M, Jolie, J, Saed-Samii, N, Warr, N, Korten, W, Zielińska, M, Salsac, M-D, Blanc, A, Jentschel, M, Köster, U, Mutti, P, Soldner, T, Simpson, GS, Drouet, F, Vancraeyenest, A, de France, G, Clément, E, Stezowski, O, Ur, CA, Urban, W, Regan, PH, Podolyák, Zs, Larijani, C, Townsley, C, Carroll, R, Wilson, E, Mach, H, Fraile, LM, Paziy, V, Olaizola, B, Vedia, V, Bruce, AM, Roberts, OJ, Smith, JF, Scheck, M, Kröll, T, Hartig, A-L, Ignatov, A, Ilieva, S, Lalkovski, S, Mărginean, N, Otsuka, Taka, Shimizu, N, Togashi, T, and Tsunoda, Y

Subjects
Nuclear Experiment
Abstract

Rapid shape changes are observed for neutron-rich nuclei with A around 100. In particular, a sudden onset of ground-state deformation is observed in the Zr and Sr isotopic chains at N = 60: Low-lying states in N≤58 nuclei are nearly spherical, while those with N≥60 have a rotational character. Nuclear lifetimes as short as a few picoseconds can be measured using fast-timing techniques with LaBr3(Ce) scintillators, yielding a key ingredient in the systematic study of the shape evolution in this region. We used neutron-induced fission of 241Pu and 235U to study lifetimes of excited states in fission fragments in the A∼100 region with the EXILL-FATIMA array located at the PF1B cold neutron beam line at the Institut Laue-Langevin. In particular, we applied the generalized centroid difference method to deduce lifetimes of low-lying states for the nuclei 98Zr (N = 58), 100Zr, and 102Zr (N≥60). The results are discussed in the context of the presumed phase transition in the Zr chain by comparing the experimental transition strengths with the theoretical calculations using the interacting boson model and the Monte Carlo shell model. ispartof: Physical Review C vol:96 issue:5 status: published

Published
2017

7. Isomer-delayed -ray spectroscopy of A = 159 - 164 midshell nuclei and the variation of K-forbidden E1 transition hindrance factors

Author

Patel, Z, Walker, Philip, Podolyak, Zsolt, Regan, Patrick, Berry, Thomas, Söderström, P-A, Watanabe, H, Ideguchi, E, Simpson, GS, Nishimura, S, Wu, Q, Xu, FR, Browne, F, Doornenbal, P, Lorusso, G, Rice, S, Sinclair, L, Sumikama, T, Wu, J, Xu, ZY, Aoi, N, Baba, H, Bello Garrote, FL, Benzoni, G, Daido, R, Dombrádi, Zs, Fang, Y, Fukuda, N, Gey, G, Go, S, Gottardo, A, Inabe, N, Isobe, T, Kameda, D, Kobayashi, K, Kobayashi, M, Komatsubara, T, Kojouharov, I, Kubo, T, Kurz, N, Kuti, I, Li, Z, Matsushita, M, Michimasa, S, Moon, C-B, Nishibata, H, Nishizuka, I, Odahara, A, Sahin, E, Sakurai, H, Schaffner, H, Suzuki, H, Takeda, H, Tanaka, M, Taprogge, J, Vajta, Zs, Yagi, A, and Yokoyama, R

Abstract

Excited states have been studied in \iso{159}{Sm}, \iso{161}{Sm}, \iso{162}{Sm} (Z~=~62), \iso{163}{Eu} (Z~=~63), and \iso{164}{Gd} (Z~=~64), populated by isomeric decay following 238U projectile fission at RIBF, RIKEN. The isomer half-lives range from 50 ns to 2.6 \mus. In comparison with other published data, revised interpretations are proposed for \iso{159}{Sm} and \iso{163}{Eu}. The first data for excited states in \iso{161}{Sm} are presented, where a 2.6 \mus isomer is assigned a three-quasiparticle, K^\pi = 17/2^- structure. The interpretation is supported by multi-quasiparticle Nilsson-BCS calculations, including the blocking of pairing correlations. A consistent set of reduced E1 hindrance factors is obtained. Limited evidence is also reported for isomeric decay in 163Sm, 164Eu and 165Eu.

Published
2017

8. K-selection in the decay of the (ν 5 2 [532] ⊗ 3 2 [411])4- isomeric state in 102Zr

Author

Browne, F, Bruce, AM, Sumikama, T, Nishizuka, I, Nishimura, S, Doornenbal, P, Lorusso, G, Soderstrom, P-A, Watanabe, H, Daido, R, Patel, Z, Rice, S, Sinclair, L, Wu, J, Xu, ZY, Yagi, A, Baba, H, Chiga, N, Carroll, R, Didierjean, F, Fang, Y, Fukuda, N, Gey, G, Ideguchi, E, Inabe, N, Isobe, T, Kameda, D, Kojouharov, I, Kurz, N, Kubo, T, Lalkovski, S, Li, Z, Lozeva, R, Nishibata, N, Odahara, A, Podolyak, Zsolt, Regan, Patrick, Roberts, OJ, Sakurai, H, Schaffner, H, Simpson, GS, Suzuki, H, Takeda, H, Tanaka, M, Taprogge, J, Werner, V, and Wieland, O

Abstract

The (ν 5 2 [532] ⊗ 3 2 [411]) 4− state in 102Zr, populated in the β-decay of 102Y, has been measured to be isomeric with a mean lifetime of 9.5(7) ns. It decays via four transitions, two of which are ∆K = 2 (to the 3+ and 4+ members of the 2+ γ band) and one is ∆K = 4 (to the 4+ member of the ground state 0+ band). The fourth (low-energy) transition is inferred to decay to an as-yet unassigned state. Hindrances of 106 were derived for the ∆K = 2 transitions compared to Weisskopf estimates and the ∆K = 4 transition hindered by a factor of 109 . These values are consistent with the decay pattern of the analogous isomeric state in the neighbouring N = 62 nucleus 100Sr and with the broader systematics of such transitions. A comparison of the hindrances for the ∆K = 4 transitions suggests that 102Zr is hardened against the γ degree of freedom compared to 100Sr.

Published
2017

9. 94 -Decay Half-lives of Neutron-Rich 55Cs to 67Ho: Experimental Feedback and Evaluation of the r-Process Rare-Earth Peak Formation

Author

Wu, J, Nishimura, S, Lorusso, G, Moller, P, Ideguchi, E, Regan, Patrick, Simpson, GS, Soderstrom, P-A, Walker, Philip, Watanabe, H, Xu, ZY, Baba, H, Browne, F, Daido, R, Doornenbal, P, Fang, YF, Gey, G, Isobe, T, Lee, PS, Liu, JJ, Li, Z, Korkulu, Z, Patel, Z, Phong, V, Rice, S, Sakurai, H, Sinclair, L, Sumikama, T, Tanaka, M, Yagi, A, Ye, YL, Yokoyama, R, Zhang, GX, Alharbi, T, Aoi, N, Bello Garrote, FL, Benzoni, G, Bruce, AM, Carroll, RJ, Chae, KY, Dombradi, Z, Estrade, A, Gottardo, A, Griffin, CJ, Kanaoka, H, Kojouharov, I, Kondev, FG, Kubono, S, Kurz, N, Kuti, I, Lalkovski, S, Lane, GJ, Lee, EJ, Lokotko, T, Lotay, Gavin, Moon, C-B, Nishibata, H, Nishizuka, I, Nita, CR, Odahara, A, Podolyak, Zsolt, Roberts, OJ, Schaffner, H, Shand, Callum, Taprogge, J, Terashima, S, Vajta, Z, and Yoshida, S

Abstract

The -decay half-lives of 94 neutron-rich nuclei 144−151Cs, 146−154Ba, 148−156La, 150−158Ce, 153−160Pr, 156−162Nd, 159−163Pm, 160−166Sm, 161−168Eu, 165−170Gd, 166−172Tb, 169−173Dy, 172−175Ho and two isomeric states 174mEr, 172mDy were measured at Radioactive Isotope Beam Factory (RIBF), providing a new experimental basis to test theoretical models. Striking, large drops of -decay half-lives are observed at neutron-number N = 97 for 58Ce, 59Pr, 60Nd, 62Sm, and N = 105 for 63Eu, 64Gd, 65Tb, 66Dy. Features in the data mirror the interplay between pairing effects and microscopic structure. r-Process network calculations performed for a range of mass models and astrophysical conditions show that the 57 half-lives measured for the first time play an important role in shaping the abundance pattern of rare-earth elements in the solar system.

Published
2017

10. Half-life of the 15/2(+) state of I-135: A test of E2 seniority relations

Author

Spagnoletti, P, Simpson, GS, Carroll, R, Regis, J-M, Blanc, A, Jentschel, M, Koster, U, Mutti, P, Soldner, T, de France, G, Ur, CA, Urban, W, Bruce, AM, Drouet, F, Fraile, LM, Gaffney, LP, Ghita, DG, Ilieva, S, Jolie, J, Korten, W, Kroell, T, Larijarni, C, Lalkovski, S, Lica, R, Mach, H, Marginean, N, Paziy, V, Podolyak, Zs, Regan, PH, Scheck, M, Saed-Samii, N, Thiamova, G, Townsley, C, Vancraeyenest, A, Vedia, V, Gargano, A, and Van Isacker, P

Published
2017

11. High-sensitivity study of levels in Al-30 following beta decay of Mg-30

Author

Olaizola, B, Mach, H, Fraile, LM, Benito, J, Borge, MJG, Boutami, R, Butler, PA, Dlouhy, Z, Fynbo, HOU, Hoff, P, Hyldegaard, S, Jeppesen, HB, Jokinen, A, Jollet, C, Korgul, A, Koster, U, Kroell, Th, Kurcewicz, W, Marechal, F, Mrazek, J, Nilsson, T, Plociennik, WA, Ruchowska, E, Schuber, R, Schwerdtfeger, W, Sewtz, M, Simpson, GS, Stanoiu, M, Tengblad, O, Thirolf, PG, Yordanov, Deyan, and Helsinki Institute of Physics

Subjects
NUCLEAR-DATA SHEETS, MOMENTS, Physical Sciences, Fysik, PICOSECOND LIFETIME MEASUREMENTS, NEUTRON, DESCENDANTS, RICH SODIUM ISOTOPES, 114 Physical sciences, REGION
Abstract

γ -ray and fast-timing spectroscopy were used to study levels in 30Al populated following the β− decay of 30Mg. Five new transitions and three new levels were located in 30Al. A search was made to identify the third 1+ state expected at an excitation energy of ∼2.5 MeV. Two new levels were found, at 3163.9 and 3362.5 keV, that are firm candidates for this state. Using the advanced time-delayed (ATD) βγγ (t) method we have measured the lifetime of the 243.8-keV state to be T1/2 = 15(4) ps, which implies that the 243.8-keV transition is mainly of M1 character. Its fast B(M1; 2+ → 3+) value of 0.10(3) W.u. is in very good agreement with the USD shell-model prediction of 0.090 W.u. The 1801.5-keV level is the only level observed in this study that could be a candidate for the second excited 2+ state. ispartof: Physical Review C vol:94 issue:5 pages:1-7 status: published

Published
2016

12. Magnetic properties of Hf-177 and Hf-180 in the strong-coupling deformed model

Author

Muto, S, Stone, NJ, Bingham, CR, Stone, JR, Walker, PM, Audi, G, Gaulard, C, Koester, U, Nikolov, J, Nishimura, K, Ohtsubo, T, Podolyak, Z, Risegari, L, Simpson, GS, Veskovic, M, and Walters, WB

Abstract

This paper reports NMR measurements of the magnetic dipole moments of two high-K isomers, the 37/2-, 51.4 m, 2740 keV state in Hf177 and the 8-, 5.5 h, 1142 keV state in Hf180 by the method of on-line nuclear orientation. Also included are results on the angular distributions of γ transitions in the decay of the Hf177 isotope. These yield high precision E2/M1 multipole mixing ratios for transitions in bands built on the 23/2+, 1.1 s, isomer at 1315 keV and on the 9/2+, 0.663 ns, isomer at 321 keV. The new results are discussed in the light of the recently reported finding of systematic dependence of the behavior of the gR parameter upon the quasiproton and quasineutron make up of high-K isomeric states in this region. © 2014 American Physical Society.

Published
2016

13. beta decay of semi-magic Cd-130: Revision and extension of the level scheme of In-130

Author

Jungclaus, A, Grawe, H, Nishimura, S, Doornenbal, P, Lorusso, G, Simpson, GS, Soederstroem, P-A, Sumikama, T, Taprogge, J, Xu, ZY, Baba, H, Browne, F, Fukuda, N, Gernhaeuser, R, Gey, G, Inabe, N, Isobe, T, Jung, HS, Kameda, D, Kim, GD, Kim, Y-K, Kojouharov, I, Kubo, T, Kurz, N, Kwon, YK, Li, Z, Sakurai, H, Schaffner, H, Shimizu, Y, Steiger, K, Suzuki, H, Takeda, H, Vajta, Zs, Watanabe, H, Wu, J, Yagi, A, Yoshinaga, K, Benzoni, G, Boenig, S, Chae, KY, Coraggio, L, Daugas, J-M, Drouet, F, Gadea, A, Gargano, A, Ilieva, S, Itaco, N, Kondev, FG, Kroell, T, Lane, GJ, Montaner-Piza, A, Moschner, K, Muecher, D, Naqvi, F, Niikura, M, Nishibata, H, Odahara, A, Orlandi, Riccardo, Patel, Z, Podolyak, Zs, and Wendt, A

Abstract

The β decay of the semi-magic nucleus 130Cd has been studied at the RIBF facility at the RIKEN Nishina Center. The high statistics of the present experiment allowed for a revision of the established level scheme of 130In and the observation of additional β feeding to high-lying core-excited states in 130In. The experimental results are compared to shell-model calculations employing a model space consisting of the full major N=50–82 neutron and Z=28–50 proton shells and the NA-14 interaction, and good agreement is found. ispartof: Physical Review C vol:94 issue:2 status: published

Published
2016

14. First observation of gamma rays emitted from excited states south-east of Sn-132: The pi g(9/2)(-1) circle times nu f(7/2) multiplet of In-132(83)

Author

Jungclaus, A, Gargano, A, Grawe, H, Taprogge, J, Nishimura, S, Doornenbal, P, Lorusso, G, Shimizu, Y, Simpson, Gs, Soderstrom, Pa, Sumikama, T, Xu, Zy, Baba, H, Browne, F, Fukuda, N, Gernhauser, R, Gey, G, Inabe, N, Isobe, T, Jung, Hs, Kameda, D, Kim, Gd, Kim, Yk, Kojouharov, I, Kubo, T, Kurz, N, Kwon, Yk, Li, Z, Sakurai, H, Schaffner, H, Steiger, K, Suzuki, H, Takeda, H, Vajta, Z, Watanabe, H, Wu, J, Yagi, A, Yoshinaga, K, Bonig, S, Coraggio, L, Daugas, Jm, Drouet, F, Gadea, A, Ilieva, S, Kroll, T, Montaner Piza, A, Moschner, K, Mucher, D, Nishibata, H, Odahara, A, Orlandi, R, Wendt, A., ITACO, Nunzio, Jungclaus, A, Gargano, A, Grawe, H, Taprogge, J, Nishimura, S, Doornenbal, P, Lorusso, G, Shimizu, Y, Simpson, G, Soderstrom, Pa, Sumikama, T, Xu, Zy, Baba, H, Browne, F, Fukuda, N, Gernhauser, R, Gey, G, Inabe, N, Isobe, T, Jung, H, Kameda, D, Kim, Gd, Kim, Yk, Kojouharov, I, Kubo, T, Kurz, N, Kwon, Yk, Li, Z, Sakurai, H, Schaffner, H, Steiger, K, Suzuki, H, Takeda, H, Vajta, Z, Watanabe, H, Wu, J, Yagi, A, Yoshinaga, K, Bonig, S, Coraggio, L, Daugas, Jm, Drouet, F, Gadea, A, Ilieva, S, Itaco, Nunzio, Kroll, T, Montaner Piza, A, Moschner, K, Mucher, D, Nishibata, H, Odahara, A, Orlandi, R, and Wendt, A.

Subjects
Nuclear Experiment
Abstract

For the first time, the γ decay of excited states has been observed in a nucleus situated in the quadrant south-east of doubly magic 132Sn, a region in which experimental information so far is limited to ground-state properties. Six γ rays with energies of 50, 86, 103, 227, 357, and 602 keV were observed following the β-delayed neutron emission from 133Cd85, populated in the projectile fission of a 238U beam at the Radioactive Isotope Beam Factory at RIKEN within the EURICA project. The new experimental information is compared to the results of a modern realistic shell-model calculation, the first one in this region very far from stability, focusing in particular on the π0g−19/2⊗ ν1f7/2 particle-hole multiplet in 132In83. In addition, theoretical estimates based on a scaling of the two-body matrix elements for the πh11/2⊗ νg9/2 analog multiplet in 208Tl127, one major proton and one major neutron shell above, are presented. ispartof: Physical Review C vol:93 issue:4 pages:1-6 status: published

Published
2016

15. beta decay of Cd-129 and excited states in In-129

Author

Taprogge, J, Jungclaus, A, Grawe, H, Nishimura, S, Doornenbal, P, Lorusso, G, Simpson, GS, Soederstroem, P-A, Sumikama, T, Xu, ZY, Baba, H, Browne, F, Fukuda, N, Gernhaeuser, R, Gey, G, Inabe, N, Isobe, T, Jung, HS, Kameda, D, Kim, GD, Kim, Y-K, Kojouharov, I, Kubo, T, Kurz, N, Kwon, YK, Li, Z, Sakurai, H, Schaffner, H, Steiger, K, Suzuki, H, Takeda, H, Vajta, Z, Watanabe, H, Wu, J, Yagi, A, Yoshinaga, K, Benzoni, G, Boenig, S, Chae, KY, Coraggio, L, Covello, A, Daugas, J-M, Drouet, F, Gadea, A, Gargano, A, Ilieva, S, Kondev, FG, Kroell, T, Lane, GJ, Montaner-Piza, A, Moschner, K, Mucher, D, Naqvi, F, Niikura, M, Nishibata, H, Odahara, A, Orlandi, R, Patel, Z, Podolyak, Z, and Wendt, A

Published
2015

16. [Beta]-decay half-lives of 110 neutron-rich nuclei across the N=82 shell gap: Implications for the mechanism and universality of the astrophysical r process

Author

Lorusso, G, Nishimura, S, Xu, ZY, Jungclaus, A, Shimizu, Y, Simpson, GS, Soederstroem, P-A, Watanabe, H, Browne, F, Doornenbal, P, Gey, G, Jung, HS, Meyer, B, Sumikama, T, Taprogge, J, Vajta, Zs, Wu, J, Baba, H, Benzoni, G, Chae, KY, Crespi, FCL, Fukuda, N, Gernhaeuser, R, Inabe, N, Isobe, T, Kajino, T, Kameda, D, Kim, GD, Kim, Y-K, Kojouharov, I, Kondev, FG, Kubo, T, Kurz, N, Kwon, YK, Lane, GJ, Li, Z, Montaner-Piza, A, Moschner, K, Naqvi, F, Niikura, M, Nishibata, H, Odahara, A, Orlandi, Riccardo, Patel, Z, Podolyak, Zs, Sakurai, H, Schaffner, H, Schury, P, Shibagaki, S, Steiger, K, Suzuki, H, Takeda, H, Wendt, A, Yagi, A, and Yoshinaga, K

Subjects
Természettudományok, Fizikai tudományok
Abstract

The β-decay half-lives of 110 neutron-rich isotopes of the elements from 37Rb to 50Sn were measured at the Radioactive Isotope Beam Factory. The 40 new half-lives follow robust systematics and highlight the persistence of shell effects. The new data have direct implications for r-process calculations and reinforce the notion that the second (A ≈ 130) and the rare-earth-element (A ≈ 160) abundance peaks may result from the freeze-out of an ðn; γÞ ⇄ ðγ; nÞ equilibrium. In such an equilibrium, the new half-lives are important factors determining the abundance of rare-earth elements, and allow for a more reliable discussion of the ispartof: Physical Review Letters vol:114 issue:19 ispartof: location:United States status: published

Published
2015

17. Isomer Decay Spectroscopy of Sm-164 and Gd-166: Midshell Collectivity Around N=100

Author

Patel, Z, Soederstroem, P-A, Podolyak, Z, Regan, PH, Walker, PM, Watanabe, H, Ideguchi, E, Simpson, GS, Liu, HL, Nishimura, S, Wu, Q, Xu, FR, Browne, F, Doornenbal, P, Lorusso, G, Rice, S, Sinclair, L, Sumikama, T, Wu, J, Xu, ZY, Aoi, N, Baba, H, Garrote, FLB, Benzoni, G, Daido, R, Fang, Y, Fukuda, N, Gey, G, Go, S, Gottardo, A, Inabe, N, Isobe, T, Kameda, D, Kobayashi, K, Kobayashi, M, Komatsubara, T, Kojouharov, I, Kubo, T, Kurz, N, Kuti, I, Li, Z, Matsushita, M, Michimasa, S, Moon, C-B, Nishibata, H, Nishizuka, I, Odahara, A, Sahin, E, Sakurai, H, Schaffner, H, Suzuki, H, Takeda, H, Tanaka, M, Taprogge, J, Vajta, Z, Yagi, A, and Yokoyama, R

Published
2014

18. Monopole-Driven Shell Evolution below the Doubly Magic Nucleus Sn 132 Explored with the Long-Lived Isomer in Pd 126

Author

Watanabe, H, Lorusso, G, Nishimura, S, Otsuka, T, Ogawa, K, Xu, ZY, Sumikama, T, Söderström, P-A, Doornenbal, P, Li, Z, Browne, F, Gey, G, Jung, HS, Taprogge, J, Vajta, Zs, Wu, J, Yagi, A, Baba, H, Benzoni, G, Chae, KY, Crespi, FCL, Fukuda, N, Gernhäuser, R, Inabe, N, Isobe, T, Jungclaus, A, Kameda, D, Kim, GD, Kim, YK, Kojouharov, I, Kondev, FG, Kubo, T, Kurz, N, Kwon, YK, Lane, GJ, Moon, C-B, Montaner-Pizá, A, Moschner, K, Naqvi, F, Niikura, M, Nishibata, H, Nishimura, D, Odahara, A, Orlandi, R, Patel, Z, Podolyák, Zs, Sakurai, H, Schaffner, H, Simpson, GS, Steiger, K, Suzuki, H, Takeda, H, Wendt, A, and Yoshinaga, K

Abstract

A new isomer with a half-life of 23.0(8) ms has been identified at 2406 keV in (126)Pd and is proposed to have a spin and parity of 10(+) with a maximally aligned configuration comprising two neutron holes in the 1h(11/2) orbit. In addition to an internal-decay branch through a hindered electric octupole transition, β decay from the long-lived isomer was observed to populate excited states at high spins in (126)Ag. The smaller energy difference between the 10(+) and 7(-) isomers in (126)Pd than in the heavier N=80 isotones can be interpreted as being ascribed to the monopole shift of the 1h(11/2) neutron orbit. The effects of the monopole interaction on the evolution of single-neutron energies below (132)Sn are discussed in terms of the central and tensor forces. ispartof: Physical Review Letters vol:113 issue:4 ispartof: location:United States status: published

Published
2014

19. Magnetic properties of Hf 177 and Hf 180 in the strong-coupling deformed model

Author

Muto, S, Stone, NJ, Bingham, CR, Stone, JR, Walker, PM, Podolyak, Z, Audi, G, Gaulard, C, Risegari, L, Köster, U, Nikolov, J, Veskovic, M, Nishimura, K, Ohtsubo, T, Simpson, GS, and Walters, WB

Abstract

This paper reports NMR measurements of the magnetic dipole moments of two high-K isomers, the 37/2-, 51.4 m, 2740 keV state in Hf177 and the 8-, 5.5 h, 1142 keV state in Hf180 by the method of on-line nuclear orientation. Also included are results on the angular distributions of γ transitions in the decay of the Hf177 isotope. These yield high precision E2/M1 multipole mixing ratios for transitions in bands built on the 23/2+, 1.1 s, isomer at 1315 keV and on the 9/2+, 0.663 ns, isomer at 321 keV. The new results are discussed in the light of the recently reported finding of systematic dependence of the behavior of the gR parameter upon the quasiproton and quasineutron make up of high-K isomeric states in this region. © 2014 American Physical Society.

Published
2014

20. Yrast 6(+) Seniority Isomers of Sn-136,Sn-138

Author

Simpson, GS, Gey, G, Jungclaus, A, Taprogge, J, Nishimura, S, Sieja, K, Doornenbal, P, Lorusso, G, Soederstroem, P-A, Sumikama, T, Xu, ZY, Baba, H, Browne, F, Fukuda, N, Inabe, N, Isobe, T, Jung, HS, Kameda, D, Kim, GD, Kim, Y-K, Kojouharov, I, Kubo, T, Kurz, N, Kwon, YK, Li, Z, Sakurai, H, Schaffner, H, Shimizu, Y, Suzuki, H, Takeda, H, Vajta, Z, Watanabe, H, Wu, J, Yagi, A, Yoshinaga, K, Boenig, S, Daugas, J-M, Drouet, F, Gernhaeuser, R, Ilieva, S, Kroell, T, Montaner-Piza, A, Moschner, K, Muecher, D, Naidja, H, Nishibata, H, Nowacki, F, Odahara, A, Orlandi, Riccardo, Steiger, K, and Wendt, A

Abstract

Delayed γ-ray cascades, originating from the decay of ð6þÞ isomeric states, in the very neutron-rich, semimagic isotopes 136;138Sn have been observed following the projectile fission of a 238U beam at RIBF, RIKEN. The wave functions of these isomeric states are proposed to be predominantly a fully aligned pair of f7=2 neutrons. Shell-model calculations, performed using a realistic effective interaction, reproduce well the energies of the excited states of these nuclei and the measured transition rates, with the exception of the BðE2; 6þ → 4þÞ rate of 136Sn, which deviates from a simple seniority scheme. Empirically reducing the νf2 7=2 orbit matrix elements produces a 4 þ 1 state with almost equal seniority 2 and 4 components, correctly reproducing the experimental BðE2; 6þ → 4þÞ rate of 136Sn. These data provide a key benchmark for shell-model interactions far from stability. ispartof: PHYSICAL REVIEW LETTERS vol:113 issue:13 pages:1-6 ispartof: location:United States status: published

Published
2014

21. 1p(3/2) Proton-Hole State in Sn-132 and the Shell Structure Along N=82

Author

Taprogge, J, Jungclaus, A, Grawe, H, Nishimura, S, Doornenbal, P, Lorusso, G, Simpson, GS, Soederstroem, P-A, Sumikama, T, Xu, ZY, Baba, H, Browne, F, Fukuda, N, Gernhaeuser, R, Gey, G, Inabe, N, Isobe, T, Jung, HS, Kameda, D, Kim, GD, Kim, Y-K, Kojouharov, I, Kubo, T, Kurz, N, Kwon, YK, Li, Z, Sakurai, H, Schaffner, H, Steiger, K, Suzuki, H, Takeda, H, Vajta, Zs, Watanabe, H, Wu, J, Yagi, A, Yoshinaga, K, Benzoni, G, Boenig, S, Chae, KY, Coraggio, L, Covello, A, Daugas, J-M, Drouet, F, Gadea, A, Gargano, A, Ilieva, S, Kondev, FG, Kroell, T, Lane, GJ, Montaner-Piza, A, Moschner, K, Muecher, D, Naqvi, F, Niikura, M, Nishibata, H, Odahara, A, Orlandi, Riccardo, Patel, Z, Podolyak, Zs, and Wendt, A

Abstract

A low-lying state in 131In82, the one-proton hole nucleus with respect to double magic 132Sn, was observed by its γ decay to the Iπ ¼ 1=2− β-emitting isomer. We identify the new state at an excitation energy of Ex ¼ 1353 keV, which was populated both in the β decay of 131Cd83 and after β-delayed neutron emission from 132Cd84, as the previously unknown πp3=2 single-hole state with respect to the 132Sn core. Exploiting this crucial new experimental information, shell-model calculations were performed to study the structure of experimentally inaccessible N ¼ 82 isotones below 132Sn. The results evidence a surprising absence of proton subshell closures along the chain of N ¼ 82 isotones. The consequences of this finding for the evolution of the N ¼ 82 shell gap along the r-process path are discussed. ispartof: Physical Review Letters vol:112 issue:13 pages:1-5 ispartof: location:United States status: published

Published
2014

22. β − decay of 65 Mn to65 Fe

Author

Olaizola, B, Fraile, LM, Mach, H, Aprahamian, A, Briz, JA, Cal-Gonzalez, J, Ghita, D, Koster, U, Kurcewicz, W, Lesher, SR, Pauwels, Dieter, Picado, E, Poves, A, Radulov, Deyan, Simpson, GS, and Udıas, JM

Abstract

The low-energy structure of 65Fe has been studied by means ofγand fast-timing spectroscopy at the ISOLDE facility, CERN. A level scheme of 65Fe populated following the β− decay of 65Mn was established for the first time. It includes 41 levels and 85 transitions. The excitation energy of the β-decaying isomer in 65Fe has been precisely determined at 393.7(2) keV. Theβ-delayed neutron emission branch was measured asPn=7.9(12)%, which cannot be reconciled with the previously reported value of 21.0(5)%. Fourγrays and four excited states in 64Fe were identified as being populated following theβ-ndecay. Four lifetimes and five lifetime limits in the subnanosecond range have been measured using the advanced time-delayedβγγ(t) method. The level scheme is compared with shell-model calculations. Tentative spin and parity assignments are proposed based on the observed transition rates, the calculations, and the systematics of the region. ispartof: Physical Review C, Nuclear Physics vol:88 issue:4 pages:1-17 status: published

Published
2013

23. Shape evolution in Ru-116,Ru-118: Triaxiality and transition between the O(6) and U(5) dynamical symmetries

Author

Soederstoerm, P-A, Lorusso, G, Watanabe, H, Nishimura, S, Doornenbal, P, Thiamova, G, Browne, F, Gey, G, Jung, HS, Sumikama, T, Taprogge, J, Vajta, Z, Wu, J, Xu, ZY, Baba, H, Benzoni, G, Chae, KY, Crespi, FCL, Fukuda, N, Gernhaeuser, R, Inabe, N, Isobe, T, Jungclaus, A, Kameda, D, Kim, GD, Kim, Y-K, Kojouharov, I, Kondev, FG, Kubo, T, Kurz, N, Kwon, YK, Lane, GJ, Li, Z, Montaner-Piza, A, Moschner, K, Naqvi, F, Niikura, M, Nishibata, H, Odahara, A, Orlandi, R, Patel, Z, Podolyak, Z, Sakurai, H, Schaffner, H, Simpson, GS, Steiger, K, Suzuki, H, Takeda, H, Wendt, A, Yagi, A, and Yoshinaga, K

Published
2013

24. Determination of the B(E3; 0$^{+} \rightarrow$ 3$^{-}$) strength in the octupole correlated nucleus $^{144}$Ba using Coulomb excitation

Author

Cocolios, TE CERN ISOLDE, Pakarinen, J CERN ISOLDE, Voulot, D CERN ISOLDE, Wenander, F CERN ISOLDE, Grahn, T University of Jyväskylä, Julin, R University of Jyväskylä, Diriken, J KU Leuven, Van Duppen, P KU Leuven, Kesteloot, N KU Leuven, Huyse, M KU Leuven, Wrzosek-Lipska, K KU Leuven, Albers, M University of Köln, Blazhev, A University of Köln, Jolie, J University of Köln, Moschner, K University of Köln, Radeck, D University of Köln, Reiter, P University of Köln, Seidlitz, M University of Köln, Warr, N University of Köln, Kwan, E Lawrence Livermore Laboratory, Wu, CY Lawrence Livermore Laboratory, Andreyev, A University of Paisley, Butler, PA University of Liverpool, Gaffney, LP University of Liverpool, Herzberg, RD University of Liverpool, Joss, DT University of Liverpool, Page, RD University of Liverpool, Gernhäuser, R TU München, Krücken, R TU München, Mücher, D TU München, Nowak, K TU München, Thirolf, P LMU München, Bloch, T TU Darmstadt, Bönig, S TU Darmstadt, Ignatov, A TU Darmstadt, Ilieva, T TU Darmstadt, Kröll, T TU Darmstadt, Scheck, M TU Darmstadt, von Schmid, M TU Darmstadt, Thürauf, M TU Darmstadt, Guttormsen, M University of Oslo, Görgen, A University of Oslo, Larsen, AC University of Oslo, Siem, S University of Oslo, Cline, D University of Rochester, Hayes, A University of Rochester, Zielinska, M CEA Saclay, Cederkäll, J Lund University, Hadynska Klek, K HIL University of Warsaw, Iwanicki, J HIL University of Warsaw, Napiorkowski, P HIL University of Warsaw, Pietak, D HIL University of Warsaw, Srebrny, J HIL University of Warsaw, Barton, C University of York, Jenkins, DG University of York, Wadsworth, R University of York, McEllistrem, MT University of Kentucky, Yates, SW University of Kentucky, Rainovski, G Sofia University, Simpson, GS LPSC Grenoble, and Wimmer, K NSCL Michigan State University

Subjects
Detectors and Experimental Techniques
Published
2011

25. g-factor measurements at RISING: The cases of Sn-127 and Sn-128

Author

Atanasova, L, Balabanski, DL, Chamoli, SK, Hass, M, Simpson, GS, Bazzacco, D, Becker, F, Bednarczyk, P, Benzoni, G, Blasi, N, Blazhev, A, Bracco, A, Brandau, C, Caceres, L, Camera, F, Crespi, FCL, Detistov, P, Doornenbal, P, Fahlander, C, Farnea, E, Georgiev, G, Gerl, J, Gladnishki, KA, Gorska, M, Grebosz, J, Hoischen, R, Ilie, G, Ionescu-Bujor, M, Iordachescu, A, Jungclaus, A, Lo Bianco, G, Kmiecik, M, Kojouharov, I, Kurz, N, Lakshmi, S, Lozeva, R, Maj, A, Montanari, D, Neyens, G, Pfuetzner, M, Pietri, S, Podolyak, Z, Prokopowicz, W, Rudolph, D, Rusev, G, Saito, TR, Saltarelli, A, Schaffner, H, Schwengner, R, Tashenov, S, Valiente-Dobon, JJ, Vermeulen, N, Walker, J, Werner-Malento, E, Wieland, O, Wollersheim, HJ, Grawe, H, and Hjorth-Jensen, M

Abstract

We report on g-factor measurements of the 19/2+ T1/2=4.5(3) μs isomer in 127Sn and the 10+ T1/2=2.69(23) μs isomer in 128Sn. These isomers were produced and spin-aligned in relativistic heavy-ion fragmentation at GSI and were selected and separated by the GSI fragment separator (FRS). The γ-rays of the isomeric decay were detected by the RISING γ-ray spectrometer. The method of time-differential perturbed angular distributions was utilized. The measured g-factors, g(19/2+; 127Sn)=− 0.17(2) and g(10+; 128Sn)=− 0.20(4), are compared with shell model calculations. The measured g-factors confirm the predominantly νh11/2− 2 and ν(s1/2− 1h11/2−2) character of the 10+ and 19/2− isomers in 128Sn and 127Sn, respectively. The results demonstrate the feasibility of the method for similar measurements in exotic neutron-rich nuclei.

Published
2010

26. New sub-mu s isomers in Sn-125,Sn-127,Sn-129 and isomer systematics of Sn124-130

Author

Lozeva, RL, Simpson, GS, Grawe, H, Neyens, G, Atanasova, LA, Balabanski, DL, Bazzacco, D, Becker, F, Bednarczyk, P, Benzoni, G, Blasi, N, Blazhev, A, Bracco, A, Brandau, C, Caceres, L, Camera, F, Chamoli, SK, Crespi, FCL, Daugas, J-M, Detistov, P, De Rydt, M, Doornenbal, P, Fahlander, C, Farnea, E, Georgiev, G, Gerl, J, Gladnishki, KA, Gorska, M, Grebosz, J, Hass, M, Hoischen, R, Ilie, G, Ionescu-Bujor, M, Iordachescu, A, Jolie, J, Jungclaus, A, Kmiecik, M, Kojouharov, I, Kurz, N, Lakshmi, SP, Lo Bianco, G, Mallion, S, Maj, A, Montanari, D, Perru, O, Pfuetzner, M, Pietri, S, Pinston, JA, Podolyak, Zsolt, Prokopowicz, W, Rudolph, D, Rusev, G, Saitoh, TR, Saltarelli, A, Schaffner, H, Schwengner, R, Tashenov, S, Turzo, K, Valiente-Dobon, JJ, Vermeulen, N, Walker, J, Werner-Malento, E, Wieland, O, and Wollersheim, H-J

Published
2008

27. First isomeric quadrupole moment measured in fragmentation reactions: The case of Fe-61(m)(9/2(+))

Author

Vermeulen, Nele, Chamoli, SK, Daugas, JM, Hass, M, Balabanski, DL, Delaroche, JP, de Oliveira-Santos, F, Georgiev, G, Girod, M, Goldring, G, Goutte, H, Grevy, S, Matea, I, Morel, P, Singh, BS Nara, Penionzkevich, Yu-E, Perrot, L, Perru, O, Peru, S, Roig, O, Sarazin, F, Simpson, GS, Sobolev, Yu, Stefan, I, Stodel, C, Yordanov, DT, and Neyens, Gerda

Subjects
polarization, Nuclear Theory, deformation, projectile fragmentation, fusion-evaporation reactions, exotic nuclei, isomer g-factor, neutron, 61Fe 9/2+ isomer, TDPAD, heavy-ion, Nuclear Experiment, nuclides, yrast decay schemes, fe-57, isotopes
Abstract

This paper demonstrates the feasibility of quadrupole moment measurements on isomeric levels populated in projectile fragmentation reactions. The neutron-rich Fe-61(9/2(+)) [E-*= 861 keV, T-1/2= 239(5) ns] isomer was produced and spin aligned by the intermediate energy fragmentation of a Ni-64 beam and implanted in a Cd single crystal. Its spectroscopic quadrupole moment Q(s)=41(6) e fm(2) agrees with mean-field based calculations using the finite-range Gogny force, suggesting a moderately deformed shape characterized by an intrinsic charge quadrupole moment Q(0)=-85 e fm(2) or Q(0)=+115 e fm(2). The present measurement paves the way for future determinations of isomeric quadrupole moments in more exotic nuclei. ispartof: Physical Review C, Nuclear physics vol:75 issue:5 pages:1-4 status: published

Published
2007

28. Core-coupled states and split proton-neutron quasiparticle multiplets in Ag122-126

Author

Lalkovski, S, Bruce, AM, Jungclaus, A, Gorska, M, Pfuetzner, M, Caceres, L, Naqvi, F, Pietri, S, Podolyak, Z, Simpson, GS, Andgren, K, Bednarczyk, P, Beck, T, Benlliure, J, Benzoni, G, Casarejos, E, Cederwall, B, Crespi, FCL, Cuenca-Garcia, JJ, Cullen, IJ, Bacelar, AMD, Detistov, P, Doornenbal, P, Farrelly, GF, Garnsworthy, AB, Geissel, H, Gelletly, W, Gerl, J, Grebosz, J, Hadinia, B, Hellstrom, M, Hinke, C, Hoischen, R, Ilie, G, Jaworski, G, Jolie, J, Khaplanov, A, Kisyov, S, Kmiecik, M, Kojouharov, I, Kumar, R, Kurz, N, Maj, A, Mandal, S, Modamio, V, Montes, F, Myalski, S, Palacz, M, Prokopowicz, W, Reiter, P, Regan, PH, Rudolph, D, Schaffner, H, Sohler, D, Steer, SJ, Tashenov, S, Walker, J, Walker, PM, Weick, H, Werner-Malento, E, Wieland, O, Wollersheim, HJ, Zhekova, M, Lalkovski, S, Bruce, AM, Jungclaus, A, Gorska, M, Pfuetzner, M, Caceres, L, Naqvi, F, Pietri, S, Podolyak, Z, Simpson, GS, Andgren, K, Bednarczyk, P, Beck, T, Benlliure, J, Benzoni, G, Casarejos, E, Cederwall, B, Crespi, FCL, Cuenca-Garcia, JJ, Cullen, IJ, Bacelar, AMD, Detistov, P, Doornenbal, P, Farrelly, GF, Garnsworthy, AB, Geissel, H, Gelletly, W, Gerl, J, Grebosz, J, Hadinia, B, Hellstrom, M, Hinke, C, Hoischen, R, Ilie, G, Jaworski, G, Jolie, J, Khaplanov, A, Kisyov, S, Kmiecik, M, Kojouharov, I, Kumar, R, Kurz, N, Maj, A, Mandal, S, Modamio, V, Montes, F, Myalski, S, Palacz, M, Prokopowicz, W, Reiter, P, Regan, PH, Rudolph, D, Schaffner, H, Sohler, D, Steer, SJ, Tashenov, S, Walker, J, Walker, PM, Weick, H, Werner-Malento, E, Wieland, O, Wollersheim, HJ, and Zhekova, M

Published
2013

29. Fission fragment spectroscopy with large Ge detector arrays

Author

Smith, Ag, Simpson, Gs, Billowes, J., Durell, Jl, Dagnall, Pj, Freeman, Sj, Leddy, M., Roach, Aa, Smith, Jf, Andrea Jungclaus, Lieb, Kp, Teich, C., Gall, Bjp, Hoellinger, F., Schulz, N., Ahmad, I., Greene, J., Algora, A., Institut de Recherches Subatomiques (IReS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Cancéropôle du Grand Est-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS), and Heyd, Yvette

Subjects
[PHYS.NEXP] Physics [physics]/Nuclear Experiment [nucl-ex], [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex]
Published
2000

30. Spin-alignment and g-factor measurement of the I-pi=12(+) isomer in Pb-192 produced in the relativistic-energy fragmentation of a U-238 beam

Author

Kmiecik, M, Maj, A, Gerl, J, Neyens, G, Atanasova, L, Balabanski, DL, Becker, F, Bednarczyk, P, Benzoni, G, Blasi, N, Bracco, A, Brambilla, S, Caceres, L, Camera, F, Ciemala, M, Crespi, FCL, Chamoli, SK, Chmel, S, Daugas, JM, Detistov, P, Doornenbal, P, Georgiev, G, Gladnishki, K, Gorska, M, Grawe, H, Grebosz, J, Hass, M, Hoischen, R, Ilie, G, Ionescu-Bujor, M, Jolie, J, Kojuharov, I, Krasznahorkay, A, Kulessa, R, Lach, M, Lakshmi, S, Leoni, S, Lo Bianco, G, Lozeva, R, Maier, KH, Mallion, S, Mazurek, K, Meczynski, W, Million, B, Montanari, D, Myalski, S, Petrache, C, Pfuetzner, M, Pietri, S, Podolyak, Z, Prokopowicz, W, Rudolph, D, Saito, N, Saito, TR, Saltarelli, A, Simpson, GS, Styczen, J, Vermeulen, N, Werner-Malento, E, Wieland, O, Wollersheim, HJ, Zieblinski, M, Kmiecik, M, Maj, A, Gerl, J, Neyens, G, Atanasova, L, Balabanski, DL, Becker, F, Bednarczyk, P, Benzoni, G, Blasi, N, Bracco, A, Brambilla, S, Caceres, L, Camera, F, Ciemala, M, Crespi, FCL, Chamoli, SK, Chmel, S, Daugas, JM, Detistov, P, Doornenbal, P, Georgiev, G, Gladnishki, K, Gorska, M, Grawe, H, Grebosz, J, Hass, M, Hoischen, R, Ilie, G, Ionescu-Bujor, M, Jolie, J, Kojuharov, I, Krasznahorkay, A, Kulessa, R, Lach, M, Lakshmi, S, Leoni, S, Lo Bianco, G, Lozeva, R, Maier, KH, Mallion, S, Mazurek, K, Meczynski, W, Million, B, Montanari, D, Myalski, S, Petrache, C, Pfuetzner, M, Pietri, S, Podolyak, Z, Prokopowicz, W, Rudolph, D, Saito, N, Saito, TR, Saltarelli, A, Simpson, GS, Styczen, J, Vermeulen, N, Werner-Malento, E, Wieland, O, Wollersheim, HJ, and Zieblinski, M

Published
2010

31. Spherical proton-neutron structure of isomeric states in Cd-128

Author

Caceres, L, Gorska, M, Jungclaus, A, Pfutzner, M, Grawe, H, Nowacki, F, Sieja, K, Pietri, S, Rudolph, D, Podolyak, Z, Regan, PH, Werner-Malento, E, Detistov, P, Lalkovski, S, Modamio, V, Walker, J, Andgren, K, Bednarczyk, P, Benlliure, J, Benzoni, G, Bruce, AM, Casarejos, E, Cederwall, B, Crespi, FCL, Doornenbal, P, Geissel, H, Gerl, J, Grebosz, J, Hadinia, B, Hellstrom, M, Hoischen, R, Ilie, G, Khaplanov, A, Kmiecik, M, Kojouharov, I, Kumar, R, Kurz, N, Maj, A, Mandal, S, Montes, F, Martinez-Pinedo, G, Myalski, S, Prokopowicz, W, Schaffner, H, Simpson, GS, Steer, SJ, Tashenov, S, Wieland, O, Wollersheim, HJ, Caceres, L, Gorska, M, Jungclaus, A, Pfutzner, M, Grawe, H, Nowacki, F, Sieja, K, Pietri, S, Rudolph, D, Podolyak, Z, Regan, PH, Werner-Malento, E, Detistov, P, Lalkovski, S, Modamio, V, Walker, J, Andgren, K, Bednarczyk, P, Benlliure, J, Benzoni, G, Bruce, AM, Casarejos, E, Cederwall, B, Crespi, FCL, Doornenbal, P, Geissel, H, Gerl, J, Grebosz, J, Hadinia, B, Hellstrom, M, Hoischen, R, Ilie, G, Khaplanov, A, Kmiecik, M, Kojouharov, I, Kumar, R, Kurz, N, Maj, A, Mandal, S, Montes, F, Martinez-Pinedo, G, Myalski, S, Prokopowicz, W, Schaffner, H, Simpson, GS, Steer, SJ, Tashenov, S, Wieland, O, and Wollersheim, HJ

Published
2009

32. Observation of isomeric decays in the r-process waiting-point nucleus Cd-130(82)

Author

Jungclaus, A, Caceres, L, Gorska, M, Pfutzner, M, Pietri, S, Werner-Malento, E, Grawe, H, Langanke, K, Martinez-Pinedo, G, Nowacki, F, Poves, A, Cuenca-Garcia, JJ, Rudolph, D, Podolyak, Z, Regan, PH, Detistov, P, Lalkovski, S, Modamio, V, Walker, J, Bednarczyk, P, Doornenbal, P, Geissel, H, Gerl, J, Grebosz, J, Kojouharov, I, Kurz, N, Prokopowicz, W, Schaffner, H, Wollersheim, HJ, Andgren, K, Benlliure, J, Benzoni, G, Bruce, AM, Casarejos, E, Cederwall, B, Crespi, FCL, Hadinia, B, Hellstrom, M, Hoischen, R, Ilie, G, Jolie, J, Khaplanov, A, Kmiecik, M, Kumar, R, Maj, A, Mandal, S, Montes, F, Myalski, S, Simpson, GS, Steer, SJ, Tashenov, S, Wieland, O, Jungclaus, A, Caceres, L, Gorska, M, Pfutzner, M, Pietri, S, Werner-Malento, E, Grawe, H, Langanke, K, Martinez-Pinedo, G, Nowacki, F, Poves, A, Cuenca-Garcia, JJ, Rudolph, D, Podolyak, Z, Regan, PH, Detistov, P, Lalkovski, S, Modamio, V, Walker, J, Bednarczyk, P, Doornenbal, P, Geissel, H, Gerl, J, Grebosz, J, Kojouharov, I, Kurz, N, Prokopowicz, W, Schaffner, H, Wollersheim, HJ, Andgren, K, Benlliure, J, Benzoni, G, Bruce, AM, Casarejos, E, Cederwall, B, Crespi, FCL, Hadinia, B, Hellstrom, M, Hoischen, R, Ilie, G, Jolie, J, Khaplanov, A, Kmiecik, M, Kumar, R, Maj, A, Mandal, S, Montes, F, Myalski, S, Simpson, GS, Steer, SJ, Tashenov, S, and Wieland, O

Published
2007

34. Excited-State Half-Lives in ^{130}Cd and the Isospin Dependence of Effective Charges.

Author

Jungclaus A, Górska M, Mikołajczuk M, Acosta J, Taprogge J, Nishimura S, Doornenbal P, Lorusso G, Simpson GS, Söderström PA, Sumikama T, Xu Z, Kumar P, Martínez-Pinedo G, Nowacki F, Van Isacker P, Baba H, Browne F, Fukuda N, Gernhäuser R, Gey G, Inabe N, Isobe T, Jung HS, Kameda D, Kim GD, Kim YK, Kojouharov I, Kubo T, Kurz N, Kwon YK, Li Z, Sakurai H, Schaffner H, Shimizu Y, Steiger K, Suzuki H, Takeda H, Vajta Z, Watanabe H, Wu J, Yagi A, Yoshinaga K, Benzoni G, Bönig S, Chae KY, Daugas JM, Drouet F, Gadea A, Ilieva S, Kondev FG, Kröll T, Lane GJ, Montaner-Pizá A, Moschner K, Naqvi F, Niikura M, Nishibata H, Odahara A, Orlandi R, Patel Z, Podolyák Z, and Wendt A

Abstract

The known I^{π}=8_{1}^{+}, E_{x}=2129-keV isomer in the semimagic nucleus ^{130}Cd_{82} was populated in the projectile fission of a ^{238}U beam at the Radioactive Isotope Beam Factory at RIKEN. The high counting statistics of the accumulated data allowed us to determine the excitation energy, E_{x}=2001.2(7)  keV, and half-life, T_{1/2}=57(3)  ns, of the I^{π}=6_{1}^{+} state based on γγ coincidence information. Furthermore, the half-life of the 8_{1}^{+} state, T_{1/2}=224(4)  ns, was remeasured with high precision. The new experimental information, combined with available data for ^{134}Sn and large-scale shell model calculations, allowed us to extract proton and neutron effective charges for ^{132}Sn, a doubly magic nucleus far-off stability. A comparison to analogous information for ^{100}Sn provides first reliable information regarding the isospin dependence of the isoscalar and isovector effective charges in heavy nuclei.

Published
2024
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35. Boulay et al. Reply.

Author

Boulay F, Simpson GS, Ichikawa Y, Kisyov S, Bucurescu D, Takamine A, Ahn DS, Asahi K, Baba H, Balabanski DL, Egami T, Fujita T, Fukuda N, Funayama C, Furukawa T, Georgiev G, Gladkov A, Hass M, Imamura K, Inabe N, Ishibashi Y, Kawaguchi T, Kawamura T, Kim W, Kobayashi Y, Kojima S, Kusoglu A, Lozeva R, Momiyama S, Mukul I, Niikura M, Nishibata H, Nishizaka T, Odahara A, Ohtomo Y, Ralet D, Sato T, Shimizu Y, Sumikama T, Suzuki H, Takeda H, Tao LC, Togano Y, Tominaga D, Ueno H, Yamazaki H, Yang XF, and Daugas JM

Published
2021
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36. g Factor of the ^{99}Zr (7/2^{+}) Isomer: Monopole Evolution in the Shape-Coexisting Region.

Author

Boulay F, Simpson GS, Ichikawa Y, Kisyov S, Bucurescu D, Takamine A, Ahn DS, Asahi K, Baba H, Balabanski DL, Egami T, Fujita T, Fukuda N, Funayama C, Furukawa T, Georgiev G, Gladkov A, Hass M, Imamura K, Inabe N, Ishibashi Y, Kawaguchi T, Kawamura T, Kim W, Kobayashi Y, Kojima S, Kusoglu A, Lozeva R, Momiyama S, Mukul I, Niikura M, Nishibata H, Nishizaka T, Odahara A, Ohtomo Y, Ralet D, Sato T, Shimizu Y, Sumikama T, Suzuki H, Takeda H, Tao LC, Togano Y, Tominaga D, Ueno H, Yamazaki H, Yang XF, and Daugas JM

Abstract

The gyromagnetic factor of the low-lying E=251.96(9)  keV isomeric state of the nucleus ^{99}Zr was measured using the time-dependent perturbed angular distribution technique. This level is assigned a spin and parity of J^{π}=7/2^{+}, with a half-life of T_{1/2}=336(5)  ns. The isomer was produced and spin aligned via the abrasion-fission of a ^{238}U primary beam at RIKEN RIBF. A magnetic moment |μ|=2.31(14)μ_{N} was deduced showing that this isomer is not single particle in nature. A comparison of the experimental values with interacting boson-fermion model IBFM-1 results shows that this state is strongly mixed with a main νd_{5/2} composition. Furthermore, it was found that monopole single-particle evolution changes significantly with the appearance of collective modes, likely due to type-II shell evolution.

Published
2020
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37. Proton Shell Evolution below ^{132}Sn: First Measurement of Low-Lying β-Emitting Isomers in ^{123,125}Ag.

Author

Chen ZQ, Li ZH, Hua H, Watanabe H, Yuan CX, Zhang SQ, Lorusso G, Nishimura S, Baba H, Browne F, Benzoni G, Chae KY, Crespi FCL, Doornenbal P, Fukuda N, Gey G, Gernhäuser R, Inabe N, Isobe T, Jiang DX, Jungclaus A, Jung HS, Jin Y, Kameda D, Kim GD, Kim YK, Kojouharov I, Kondev FG, Kubo T, Kurz N, Kwon YK, Li XQ, Lou JL, Lane GJ, Li CG, Luo DW, Montaner-Pizá A, Moschner K, Niu CY, Naqvi F, Niikura M, Nishibata H, Odahara A, Orlandi R, Patel Z, Podolyák Z, Sumikama T, Söderström PA, Sakurai H, Schaffner H, Simpson GS, Steiger K, Suzuki H, Taprogge J, Takeda H, Vajta Z, Wang HK, Wu J, Wendt A, Wang CG, Wu HY, Wang X, Wu CG, Xu C, Xu ZY, Yagi A, Ye YL, and Yoshinaga K

Abstract

The β-delayed γ-ray spectroscopy of neutron-rich ^{123,125}Ag isotopes is investigated at the Radioactive Isotope Beam Factory of RIKEN, and the long-predicted 1/2^{-} β-emitting isomers in ^{123,125}Ag are identified for the first time. With the new experimental results, the systematic trend of energy spacing between the lowest 9/2^{+} and 1/2^{-} levels is extended in Ag isotopes up to N=78, providing a clear signal for the reduction of the Z=40 subshell gap in Ag towards N=82. Shell-model calculations with the state-of-the-art V_{MU} plus M3Y spin-orbit interaction give a satisfactory description of the low-lying states in ^{123,125}Ag. The tensor force is found to play a crucial role in the evolution of the size of the Z=40 subshell gap. The observed inversion of the single-particle levels around ^{123}Ag can be well interpreted in terms of the monopole shift of the π1g_{9/2} orbitals mainly caused by the increasing occupation of ν1h_{11/2} orbitals.

Published
2019
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38. 94 β-Decay Half-Lives of Neutron-Rich _{55}Cs to _{67}Ho: Experimental Feedback and Evaluation of the r-Process Rare-Earth Peak Formation.

Author

Wu J, Nishimura S, Lorusso G, Möller P, Ideguchi E, Regan PH, Simpson GS, Söderström PA, Walker PM, Watanabe H, Xu ZY, Baba H, Browne F, Daido R, Doornenbal P, Fang YF, Gey G, Isobe T, Lee PS, Liu JJ, Li Z, Korkulu Z, Patel Z, Phong V, Rice S, Sakurai H, Sinclair L, Sumikama T, Tanaka M, Yagi A, Ye YL, Yokoyama R, Zhang GX, Alharbi T, Aoi N, Bello Garrote FL, Benzoni G, Bruce AM, Carroll RJ, Chae KY, Dombradi Z, Estrade A, Gottardo A, Griffin CJ, Kanaoka H, Kojouharov I, Kondev FG, Kubono S, Kurz N, Kuti I, Lalkovski S, Lane GJ, Lee EJ, Lokotko T, Lotay G, Moon CB, Nishibata H, Nishizuka I, Nita CR, Odahara A, Podolyák Z, Roberts OJ, Schaffner H, Shand C, Taprogge J, Terashima S, Vajta Z, and Yoshida S

Abstract

The β-decay half-lives of 94 neutron-rich nuclei ^{144-151}Cs, ^{146-154}Ba, ^{148-156}La, ^{150-158}Ce, ^{153-160}Pr, ^{156-162}Nd, ^{159-163}Pm, ^{160-166}Sm, ^{161-168}Eu, ^{165-170}Gd, ^{166-172}Tb, ^{169-173}Dy, ^{172-175}Ho, and two isomeric states ^{174m}Er, ^{172m}Dy were measured at the Radioactive Isotope Beam Factory, providing a new experimental basis to test theoretical models. Strikingly large drops of β-decay half-lives are observed at neutron-number N=97 for _{58}Ce, _{59}Pr, _{60}Nd, and _{62}Sm, and N=105 for _{63}Eu, _{64}Gd, _{65}Tb, and _{66}Dy. Features in the data mirror the interplay between pairing effects and microscopic structure. r-process network calculations performed for a range of mass models and astrophysical conditions show that the 57 half-lives measured for the first time play an important role in shaping the abundance pattern of rare-earth elements in the solar system.

Published
2017
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39. Investigating the Pygmy Dipole Resonance Using β Decay.

Author

Scheck M, Mishev S, Ponomarev VY, Chapman R, Gaffney LP, Gregor ET, Pietralla N, Spagnoletti P, Savran D, and Simpson GS

Abstract

In this contribution it is explored whether γ-ray spectroscopy following β decay with high Q values from mother nuclei with low ground-state spin can be exploited as a probe for the pygmy dipole resonance. The suitability of this approach is demonstrated by a comparison between data from photon scattering, ^{136}Xe(γ,γ^{'}), and ^{136}I [J_{0}^{π}=(1^{-})]→^{136}Xe^{*} β-decay data. It is demonstrated that β decay populates 1^{-} levels associated with the pygmy dipole resonance, but only a fraction of those. The complementary insight into the wave functions probed by β decay is elucidated by calculations within the quasiparticle phonon model. It is demonstrated that β decay dominantly populates complex configurations, which are only weakly excited in inelastic scattering experiments.

Published
2016
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40. β-Decay Half-Lives of 110 Neutron-Rich Nuclei across the N=82 Shell Gap: Implications for the Mechanism and Universality of the Astrophysical r Process.

Author

Lorusso G, Nishimura S, Xu ZY, Jungclaus A, Shimizu Y, Simpson GS, Söderström PA, Watanabe H, Browne F, Doornenbal P, Gey G, Jung HS, Meyer B, Sumikama T, Taprogge J, Vajta Z, Wu J, Baba H, Benzoni G, Chae KY, Crespi FC, Fukuda N, Gernhäuser R, Inabe N, Isobe T, Kajino T, Kameda D, Kim GD, Kim YK, Kojouharov I, Kondev FG, Kubo T, Kurz N, Kwon YK, Lane GJ, Li Z, Montaner-Pizá A, Moschner K, Naqvi F, Niikura M, Nishibata H, Odahara A, Orlandi R, Patel Z, Podolyák Z, Sakurai H, Schaffner H, Schury P, Shibagaki S, Steiger K, Suzuki H, Takeda H, Wendt A, Yagi A, and Yoshinaga K

Abstract

The β-decay half-lives of 110 neutron-rich isotopes of the elements from _{37}Rb to _{50}Sn were measured at the Radioactive Isotope Beam Factory. The 40 new half-lives follow robust systematics and highlight the persistence of shell effects. The new data have direct implications for r-process calculations and reinforce the notion that the second (A≈130) and the rare-earth-element (A≈160) abundance peaks may result from the freeze-out of an (n,γ)⇄(γ,n) equilibrium. In such an equilibrium, the new half-lives are important factors determining the abundance of rare-earth elements, and allow for a more reliable discussion of the r process universality. It is anticipated that universality may not extend to the elements Sn, Sb, I, and Cs, making the detection of these elements in metal-poor stars of the utmost importance to determine the exact conditions of individual r-process events.

Published
2015
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41. Isomer decay spectroscopy of 164Sm and 166Gd: midshell collectivity around N=100.

Author

Patel Z, Söderström PA, Podolyák Z, Regan PH, Walker PM, Watanabe H, Ideguchi E, Simpson GS, Liu HL, Nishimura S, Wu Q, Xu FR, Browne F, Doornenbal P, Lorusso G, Rice S, Sinclair L, Sumikama T, Wu J, Xu ZY, Aoi N, Baba H, Bello Garrote FL, Benzoni G, Daido R, Fang Y, Fukuda N, Gey G, Go S, Gottardo A, Inabe N, Isobe T, Kameda D, Kobayashi K, Kobayashi M, Komatsubara T, Kojouharov I, Kubo T, Kurz N, Kuti I, Li Z, Matsushita M, Michimasa S, Moon CB, Nishibata H, Nishizuka I, Odahara A, Şahin E, Sakurai H, Schaffner H, Suzuki H, Takeda H, Tanaka M, Taprogge J, Vajta Z, Yagi A, and Yokoyama R

Abstract

Excited states in the N=102 isotones 166Gd and 164Sm have been observed following isomeric decay for the first time at RIBF, RIKEN. The half-lives of the isomeric states have been measured to be 950(60) and 600(140) ns for 166Gd and 164Sm, respectively. Based on the decay patterns and potential energy surface calculations, including β6 deformation, a spin and parity of 6- has been assigned to the isomeric states in both nuclei. Collective observables are discussed in light of the systematics of the region, giving insight into nuclear shape evolution. The decrease in the ground-band energies of 166Gd and 164Sm (N=102) compared to 164Gd and 162Sm (N=100), respectively, presents evidence for the predicted deformed shell closure at N=100.

Published
2014
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42. Yrast 6⁺ seniority isomers of (136,138)Sn.

Author

Simpson GS, Gey G, Jungclaus A, Taprogge J, Nishimura S, Sieja K, Doornenbal P, Lorusso G, Söderström PA, Sumikama T, Xu ZY, Baba H, Browne F, Fukuda N, Inabe N, Isobe T, Jung HS, Kameda D, Kim GD, Kim YK, Kojouharov I, Kubo T, Kurz N, Kwon YK, Li Z, Sakurai H, Schaffner H, Shimizu Y, Suzuki H, Takeda H, Vajta Z, Watanabe H, Wu J, Yagi A, Yoshinaga K, Bönig S, Daugas JM, Drouet F, Gernhäuser R, Ilieva S, Kröll T, Montaner-Pizá A, Moschner K, Mücher D, Naïdja H, Nishibata H, Nowacki F, Odahara A, Orlandi R, Steiger K, and Wendt A

Abstract

Delayed γ-ray cascades, originating from the decay of (6⁺) isomeric states, in the very neutron-rich, semimagic isotopes (136,138)Sn have been observed following the projectile fission of a ²³⁸U beam at RIBF, RIKEN. The wave functions of these isomeric states are proposed to be predominantly a fully aligned pair of f(7/2) neutrons. Shell-model calculations, performed using a realistic effective interaction, reproduce well the energies of the excited states of these nuclei and the measured transition rates, with the exception of the B(E2;6⁺→4⁺) rate of ¹³⁶Sn, which deviates from a simple seniority scheme. Empirically reducing the νf(7/2)(2) orbit matrix elements produces a 4₁⁺ state with almost equal seniority 2 and 4 components, correctly reproducing the experimental B(E2;6⁺→4⁺) rate of ¹³⁶Sn. These data provide a key benchmark for shell-model interactions far from stability.

Published
2014
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43. Monopole-driven shell evolution below the doubly magic nucleus 132Sn explored with the long-lived isomer in 126Pd.

Author

Watanabe H, Lorusso G, Nishimura S, Otsuka T, Ogawa K, Xu ZY, Sumikama T, Söderström PA, Doornenbal P, Li Z, Browne F, Gey G, Jung HS, Taprogge J, Vajta Z, Wu J, Yagi A, Baba H, Benzoni G, Chae KY, Crespi FC, Fukuda N, Gernhäuser R, Inabe N, Isobe T, Jungclaus A, Kameda D, Kim GD, Kim YK, Kojouharov I, Kondev FG, Kubo T, Kurz N, Kwon YK, Lane GJ, Moon CB, Montaner-Pizá A, Moschner K, Naqvi F, Niikura M, Nishibata H, Nishimura D, Odahara A, Orlandi R, Patel Z, Podolyák Z, Sakurai H, Schaffner H, Simpson GS, Steiger K, Suzuki H, Takeda H, Wendt A, and Yoshinaga K

Abstract

A new isomer with a half-life of 23.0(8) ms has been identified at 2406 keV in (126)Pd and is proposed to have a spin and parity of 10(+) with a maximally aligned configuration comprising two neutron holes in the 1h(11/2) orbit. In addition to an internal-decay branch through a hindered electric octupole transition, β decay from the long-lived isomer was observed to populate excited states at high spins in (126)Ag. The smaller energy difference between the 10(+) and 7(-) isomers in (126)Pd than in the heavier N=80 isotones can be interpreted as being ascribed to the monopole shift of the 1h(11/2) neutron orbit. The effects of the monopole interaction on the evolution of single-neutron energies below (132)Sn are discussed in terms of the central and tensor forces.

Published
2014
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44. Circumferential resection margin (CRM) positivity after MRI assessment and adjuvant treatment in 189 patients undergoing rectal cancer resection.

Author

Simpson GS, Eardley N, McNicol F, Healey P, Hughes M, and Rooney PS

Subjects
Adult, Aged, Aged, 80 and over, Chemotherapy, Adjuvant, Female, Humans, Male, Middle Aged, Neoplasm Staging, Radiotherapy, Adjuvant, Magnetic Resonance Imaging, Neoadjuvant Therapy, Rectal Neoplasms pathology, Rectal Neoplasms surgery, Rectum pathology, Rectum surgery
Abstract

Purpose: The management of rectal cancer relies on accurate MRI staging. Multi-modal treatments can downstage rectal cancer prior to surgery and may have an effect on MRI accuracy. We aim to correlate the findings of MRI staging of rectal cancer with histological analysis, the effect of neoadjuvant therapy on this and the implications of circumferential resection margin (CRM) positivity following neoadjuvant therapy., Methods: An analysis of histological data and radiological staging of all cases of rectal cancer in a single centre between 2006 and 2011 were conducted., Results: Two hundred forty-one patients had histologically proved rectal cancer during the study period. One hundred eighty-two patients underwent resection. Median age was 66.6 years, and male to female ratio was 13:5. R1 resection rate was 11.1%. MRI assessments of the circumferential resection margin in patients without neoadjuvant radiotherapy were 93.6 and 88.1% in patients who underwent neoadjuvant radiotherapy. Eighteen patients had predicted positive margins following chemoradiotherapy, of which 38.9% had an involved CRM on histological analysis., Conclusions: MRI assessment of the circumferential resection margin in rectal cancer is associated with high accuracy. Neoadjuvant chemoradiotherapy has a detrimental effect on this accuracy, although accuracy remains high. In the presence of persistently predicted positive margins, complete resection remains achievable but may necessitate a more radical approach to resection.

Published
2014
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45. 1p3/2 proton-hole state in 132Sn and the shell structure along N = 82.

Author

Taprogge J, Jungclaus A, Grawe H, Nishimura S, Doornenbal P, Lorusso G, Simpson GS, Söderström PA, Sumikama T, Xu ZY, Baba H, Browne F, Fukuda N, Gernhäuser R, Gey G, Inabe N, Isobe T, Jung HS, Kameda D, Kim GD, Kim YK, Kojouharov I, Kubo T, Kurz N, Kwon YK, Li Z, Sakurai H, Schaffner H, Steiger K, Suzuki H, Takeda H, Vajta Z, Watanabe H, Wu J, Yagi A, Yoshinaga K, Benzoni G, Bönig S, Chae KY, Coraggio L, Covello A, Daugas JM, Drouet F, Gadea A, Gargano A, Ilieva S, Kondev FG, Kröll T, Lane GJ, Montaner-Pizá A, Moschner K, Mücher D, Naqvi F, Niikura M, Nishibata H, Odahara A, Orlandi R, Patel Z, Podolyák Z, and Wendt A

Abstract

A low-lying state in 131In82, the one-proton hole nucleus with respect to double magic 132Sn, was observed by its γ decay to the Iπ=1/2- β-emitting isomer. We identify the new state at an excitation energy of Ex=1353  keV, which was populated both in the β decay of 131Cd83 and after β-delayed neutron emission from 132Cd84, as the previously unknown πp3/2 single-hole state with respect to the 132Sn core. Exploiting this crucial new experimental information, shell-model calculations were performed to study the structure of experimentally inaccessible N=82 isotones below 132Sn. The results evidence a surprising absence of proton subshell closures along the chain of N=82 isotones. The consequences of this finding for the evolution of the N=82 shell gap along the r-process path are discussed.

Published
2014
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46. The aetiology of delay to commencement of adjuvant chemotherapy following colorectal resection.

Author

Simpson GS, Smith R, Sutton P, Shekouh A, McFaul C, Johnson M, and Vimalachandran D

Subjects
Adenocarcinoma drug therapy, Aged, Chemotherapy, Adjuvant statistics & numerical data, Colectomy methods, Colectomy statistics & numerical data, Colorectal Neoplasms drug therapy, Female, Humans, Laparoscopy statistics & numerical data, Male, Middle Aged, Prospective Studies, Regression Analysis, Time-to-Treatment, Adenocarcinoma surgery, Colorectal Neoplasms surgery
Abstract

Purpose: Timely administration of adjuvant chemotherapy following colorectal resection is associated with improved outcome. We aim to assess the factors which are associated with delay to adjuvant chemotherapy in patients who underwent colorectal resection as part of an enhanced recovery protocol., Method: A univariate and multivariate analysis of patient data collected as part of a prospectively maintained database of colorectal cancer patients between 2007 and 2012., Results: 166 patients underwent colorectal resection followed by adjuvant chemotherapy. Median postoperative hospital stay was 6 days, and time to commencement of adjuvant chemotherapy was 50 days. Longer inpatient stay correlated with increased time to adjuvant chemotherapy (P = 0.05). Factors found to be independently associated with duration of hospital stay and time to commencement of adjuvant chemotherapy included stoma formation (P = 0.032), anastaomotic leak (P = 0.027), and preoperative albumin (P = 0.027). The use of laparoscopic surgery was associated with shorter time to adjuvant chemotherapy but did not reach significance (P = 0.143)., Conclusion: A number of independent variables associated with delay to adjuvant therapy previously not described have been identified. Further work may be required to elucidate the effect that these variables have on long-term outcome.

Published
2014
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47. Isomers in 128Pd and 126Pd: evidence for a robust shell closure at the neutron magic number 82 in exotic palladium isotopes.

Author

Watanabe H, Lorusso G, Nishimura S, Xu ZY, Sumikama T, Söderström PA, Doornenbal P, Browne F, Gey G, Jung HS, Taprogge J, Vajta Z, Wu J, Yagi A, Baba H, Benzoni G, Chae KY, Crespi FC, Fukuda N, Gernhäuser R, Inabe N, Isobe T, Jungclaus A, Kameda D, Kim GD, Kim YK, Kojouharov I, Kondev FG, Kubo T, Kurz N, Kwon YK, Lane GJ, Li Z, Moon CB, Montaner-Pizá A, Moschner K, Naqvi F, Niikura M, Nishibata H, Nishimura D, Odahara A, Orlandi R, Patel Z, Podolyák Z, Sakurai H, Schaffner H, Simpson GS, Steiger K, Suzuki H, Takeda H, Wendt A, and Yoshinaga K

Abstract

The level structures of the very neutron-rich nuclei 128Pd and 126Pd have been investigated for the first time. In the r-process waiting-point nucleus 128Pd, a new isomer with a half-life of 5.8(8) μs is proposed to have a spin and parity of 8(+) and is associated with a maximally aligned configuration arising from the g(9/2) proton subshell with seniority υ=2. For 126Pd, two new isomers have been identified with half-lives of 0.33(4) and 0.44(3) μs. The yrast 2(+) energy is much higher in 128Pd than in 126Pd, while the level sequence below the 8(+) isomer in 128Pd is similar to that in the N=82 isotone 130Cd. The electric quadrupole transition that depopulates the 8(+) isomer in 128Pd is more hindered than the corresponding transition in 130Cd, as expected in the seniority scheme for a semimagic, spherical nucleus. These experimental findings indicate that the shell closure at the neutron number N=82 is fairly robust in the neutron-rich Pd isotopes.

Published
2013
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48. Incidental complete excision of appendiceal gastric cancer metastasis.

Author

Simpson GS, Mahapatra SR, and Evans J

Abstract

Gastric cancer is a common malignancy with high recurrence rates following surgical resection. A common site of disease recurrence is the peritoneum. We report the case of a 73-year-old female who had previously undergone a total gastrectomy for gastric cancer who presented acutely with features classical of acute appendicitis and underwent open appendectomy. Histological analysis showed metastasis of gastric cancer with clear resection margins. The patient recovered fully and has remained disease-free for 14 months following presentation. Peritoneal metastasis is associated with difficulty in treatment and poor prognosis. The unplanned excision of this patient's peritoneal metastasis has yielded a favourable clinical outcome in a difficult clinical situation., (Published by Oxford University Press and JSCR Publishing Ltd. All rights reserved. © The Author 2013.)

Published
2013
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49. Mutations in SYNGAP1 cause intellectual disability, autism, and a specific form of epilepsy by inducing haploinsufficiency.

Author

Berryer MH, Hamdan FF, Klitten LL, Møller RS, Carmant L, Schwartzentruber J, Patry L, Dobrzeniecka S, Rochefort D, Neugnot-Cerioli M, Lacaille JC, Niu Z, Eng CM, Yang Y, Palardy S, Belhumeur C, Rouleau GA, Tommerup N, Immken L, Beauchamp MH, Patel GS, Majewski J, Tarnopolsky MA, Scheffzek K, Hjalgrim H, Michaud JL, and Di Cristo G

Subjects
Adolescent, Amino Acid Sequence, Autistic Disorder physiopathology, Blotting, Western, Child, Child, Preschool, Cloning, Molecular, Epilepsy physiopathology, Exome, Extracellular Signal-Regulated MAP Kinases genetics, Female, HEK293 Cells, Humans, Intellectual Disability physiopathology, Male, Molecular Sequence Data, Mutation, Missense, Phenotype, Phosphorylation, Protein Conformation, Sequence Analysis, DNA, Transfection, ras GTPase-Activating Proteins metabolism, Autistic Disorder genetics, Epilepsy genetics, Haploinsufficiency, Intellectual Disability genetics, ras GTPase-Activating Proteins genetics
Abstract

De novo mutations in SYNGAP1, which codes for a RAS/RAP GTP-activating protein, cause nonsyndromic intellectual disability (NSID). All disease-causing point mutations identified until now in SYNGAP1 are truncating, raising the possibility of an association between this type of mutations and NSID. Here, we report the identification of the first pathogenic missense mutations (c.1084T>C [p.W362R], c.1685C>T [p.P562L]) and three novel truncating mutations (c.283dupC [p.H95PfsX5], c.2212_2213del [p.S738X], and (c.2184del [p.N729TfsX31]) in SYNGAP1 in patients with NSID. A subset of these patients also showed ataxia, autism, and a specific form of generalized epilepsy that can be refractory to treatment. All of these mutations occurred de novo, except c.283dupC, which was inherited from a father who is a mosaic. Biolistic transfection of wild-type SYNGAP1 in pyramidal cells from cortical organotypic cultures significantly reduced activity-dependent phosphorylated extracellular signal-regulated kinase (pERK) levels. In contrast, constructs expressing p.W362R, p.P562L, or the previously described p.R579X had no significant effect on pERK levels. These experiments suggest that the de novo missense mutations, p.R579X, and possibly all the other truncating mutations in SYNGAP1 result in a loss of its function. Moreover, our study confirms the involvement of SYNGAP1 in autism while providing novel insight into the epileptic manifestations associated with its disruption., (© 2012 WILEY PERIODICALS, INC.)

Published
2013
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50. Magnetic dipole moment of the doubly-closed-shell plus one proton nucleus 49Sc.

Author

Ohtsubo T, Stone NJ, Stone JR, Towner IS, Bingham CR, Gaulard C, Köster U, Muto S, Nikolov J, Nishimura K, Simpson GS, Soti G, Veskovic M, Walters WB, and Wauters F

Abstract

The nucleus 49Sc, having a single f(7/2) proton outside doubly magic 48Ca (Z=20, N=28), is one of the very few isotopes which makes possible testing of the fundamental theory of nuclear magnetism. The magnetic moment has been measured by online β NMR of nuclei oriented at milli-Kelvin temperatures to be (+)5.616(25)  μ(N). The result is discussed in terms of a detailed theory of the structure of the magnetic moment operator, showing excellent agreement with calculated departure from the f(7/2) Schmidt limit extreme single-particle value. The measurement completes the sequence of moments of Sc isotopes with even numbers of f(7/2) neutrons: the first such isotopic chain between two major shells for which a full set of moment measurements exists. The result further completes the isotonic sequence of ground-state moments of nuclei with an odd number of f(7/2) protons coupled to a closed subshell of f(7/2) neutrons. Comparison with a recent shell-model calculation of the latter sequence is made.

Published
2012
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