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Your search keyword '"Lynch, K. M."' showing total 7 results
Start Over Author "Lynch, K. M." Topic [phys.nexp]physics [physics]/nuclear experiment [nucl-ex]
7 results on '"Lynch, K. M."'

1. Laser Spectroscopy of Neutron-Rich $^{207,208}$Hg Isotopes: Illuminating the Kink and Odd-Even Staggering in Charge Radii across the $N=126$ Shell Closure

Author

Day Goodacre, T., Afanasjev, A. V., Barzakh, A. E., Marsh, B. A., Sels, S., Ring, P., Nakada, H., Andreyev, A. N., Van Duppen, P., Althubiti, N. A., Andel, B., Atanasov, D., Billowes, J., Blaum, K., Cocolios, T. E., Cubiss, J. G., Farooq-Smith, G. J., Fedorov, D. V., Fedosseev, V. N., Flanagan, K. T., Gaffney, L. P., Ghys, L., Huyse, M., Kreim, S., Lunney, D., Lynch, K. M., Manea, V., Martinez Palenzuela, Y., Molkanov, P. L., Rosenbusch, M., Rossel, R. E., Rothe, S., Schweikhard, L., Seliverstov, M. D., Spagnoletti, P., Van Beveren, C., Veinhard, M., Verstraelen, E., Welker, A., Wendt, K., Wienholtz, F., Wolf, R. N., Zadvornaya, A., Zuber, K., Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), and Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Nuclear Theory, nucl-th, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], FOS: Physical sciences, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], nucl-ex, Nuclear Theory (nucl-th), Nuclear Physics - Theory, Nuclear Physics - Experiment, Nuclear Experiment (nucl-ex), Präzisionsexperimente - Abteilung Blaum, Nuclear Experiment, Nuclear Physics
Abstract

The mean-square charge radii of $^{207,208}$Hg ($Z=80, N=127,128$) have been studied for the first time and those of $^{202,203,206}$Hg ($N=122,123,126$) remeasured by the application of in-source resonance-ionization laser spectroscopy at ISOLDE (CERN). The characteristic \textit{kink} in the charge radii at the $N=126$ neutron shell closure has been revealed, providing the first information on its behavior below the $Z=82$ proton shell closure. A theoretical analysis has been performed within relativistic Hartree-Bogoliubov and non-relativistic Hartree-Fock-Bogoliubov approaches, considering both the new mercury results and existing lead data. Contrary to previous interpretations, it is demonstrated that both the kink at $N=126$ and the odd-even staggering (OES) in its vicinity can be described predominately at the mean-field level, and that pairing does not need to play a crucial role in their origin. A new OES mechanism is suggested, related to the staggering in the occupation of the different neutron orbitals in odd- and even-$A$ nuclei, facilitated by particle-vibration coupling for odd-$A$ nuclei., Comment: 7 pages, 5 figures, Physical Review C, in press

Published
2021
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2. Shape coexistence in $^187Au$ studied by laser spectroscopy

Author

Barzakh, A. E., Atanasov, D., Andreyev, A. N., Monthery, M. Al, Althubiti, N. A., Andel, B., Antalic, S., Blaum, K., Cocolios, T. E., Cubiss, J. G., Van Duppen, P., Goodacre, T. Day, de Roubin, A., Farooq-Smith, G. J., Fedorov, D. V., Fedosseev, V. N., Fink, D. A., Gaffney, L. P., Ghys, L., Harding, R. D., Huyse, M., Imai, N., Kreim, S., Lunney, D., Lynch, K. M., Manea, V., Marsh, B. A., Palenzuela, Y. Martinez, Molkanov, P. L., Neidherr, D., Rosenbusch, M., Rossel, R. E., Rothe, S., Schweikhard, L., Seliverstov, M. D., Sels, S., Van Beveren, C., Verstraelen, E., Welker, A., Wienholtz, F., Wolf, R. N., Zuber, K., Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)

Subjects
TheoryofComputation_ANALYSISOFALGORITHMSANDPROBLEMCOMPLEXITY, Physics::Atomic and Molecular Clusters, ddc:530, Nuclear Physics - Experiment, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Präzisionsexperimente - Abteilung Blaum, Nuclear Structure
Abstract

Physical review / C 101(6), 064321 (2020). doi:10.1103/PhysRevC.101.064321, Published by APS, Woodbury, NY

Published
2020
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3. $β$ -delayed fission of isomers in $^{188}$Bi

Author

Andel, B, Andreyev, A N, Antalic, S, Al Monthery, M, Barzakh, A, Bissell, M L, Chrysalidis, K, Cocolios, T E, Cubiss, J G, Day Goodacre, T, Dubray, N, Farooq-Smith, G J, Fedorov, D V, Fedosseev, V N, Gaffney, L P, Garcia Ruiz, R F, Goriely, S, Granados, C, Harding, R D, Heinke, R, Hilaire, S, Huyse, M, Lemaître, J F, Lynch, K M, Marsh, B A, Molkanov, P, Mosat, P, Péru, S, Raison, C, Rothe, S, Seiffert, C, Seliverstov, M D, Sels, S, Studer, D, Sundberg, J, Van Duppen, P, Direction des Applications Militaires (DAM), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)

Subjects
Nuclear Physics - Experiment, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment, Nuclear Structure
Abstract

International audience; $β$-delayed fission ($β$DF) decay of a low-spin (ls) and a high-spin (hs) isomer in $^{188}$Bi was studied at the ISOLDE facility at CERN. Isomer-selective laser ionization and time gating were employed to investigate each isomer separately and their $β$DF partial half-lives were determined: $T_{1/2\mathrm{p},β\mathrm{DF}} (^{188}\mathrm{Bi^{ls}})=5.6(8)×10^3$ s and $T_{1/2\mathrm{p},β\mathrm{DF}} (^{188}\mathrm{Bi^{hs}})=1.7(6)×10^3$ s. This work is the first βDF study of two states in one isotope and allows the spin dependence of low-energy fission to be explored. The fission fragment mass distribution of a daughter nuclide $^{188}$Pb, following the $β$ decay of the high-spin isomer, was deduced and indicates a mixture of symmetric and asymmetric fission modes. Experimental results were compared with self-consistent mean-field calculations based on the finite-range Gogny D1M interaction. To reproduce the measured $T_{1/2\mathrm{p},β\mathrm{DF}} (^{188}\mathrm{Bi^{hs}})$, the calculated fission barrier of $^{188}$Pb had to be reduced by ≈30%. After this reduction, the measured $T_{1/2\mathrm{p},β\mathrm{DF}} (^{188}\mathrm{Bi^{ls}})$ was in agreement with calculations for a few possible configurations for $^{188}\mathrm{Bi^{ls}}$. Theoretical $β$DF probabilities for these configurations were found to be lower by a factor of 4–9 than the $β$DF probability of $^{188}\mathrm{Bi^{hs}}$. The fission fragment mass distribution of $^{188}$Pb was compared to the scission-point model SPY and the calculations based on the finite-range liquid-drop model. The first observation of $β$DF for $^{190}$Bi is also reported.

Published
2020
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4. Charge radii and electromagnetic moments of $^{195 – 211}$At

Author

Cubiss, J. G., Barzakh, A. E., Seliverstov, M. D., Andreyev, A. N., Andel, B., Antalic, S., Ascher, P., Atanasov, D., Beck, D., Bieroń, J., Blaum, K., Borgmann, Ch., Breitenfeldt, M., Capponi, L, Cocolios, T. E., Day Goodacre, T., Derkx, X., De Witte, H., Elseviers, J., Fedorov, D. V., Fedosseev, V N, Fritzsche, S., Gaffney, L. P., George, S., Ghys, L., Heßberger, F. P., Huyse, M., Imai, N., Kalaninová, Z., Kisler, D., Köster, U., Kowalska, M., Kreim, S., Lane, J. F. W., Liberati, V., Lunney, D., Lynch, K. M., Manea, V., Marsh, B. A., Mitsuoka, S., Molkanov, P. L., Nagame, Y., Neidherr, D., Nishio, K., Ota, S., Pauwels, D., Popescu, L., Radulov, D., Rapisarda, E., Revill, J. P., Rosenbusch, M., Rossel, R.E., Rothe, S., Sandhu, K., Schweikhard, L., Sels, S., Truesdale, V. L., Van Beveren, C., Van den Bergh, P., Wakabayashi, Y., Van Duppen, P., Wendt, K.D.A., Wienholtz, F., Whitmore, B. W., Wilson, G. L., Wolf, R.N., Zuber, K, Laboratoire de physique corpusculaire de Caen (LPCC), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Institut Laue-Langevin (ILL), ILL, Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Normandie Université (NU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
ddc:530, Physics::Atomic Physics, Präzisionsexperimente - Abteilung Blaum, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment
Abstract

Physical review / C 97(5), 054327 (2018). doi:10.1103/PhysRevC.97.054327, Published by Inst., Woodbury, NY

Published
2018
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5. Laser and decay spectroscopy of the short-lived isotope Fr 214 in the vicinity of the N = 126 shell closure

Author

Farooq-Smith, G. J., Cocolios, T. E., Billowes, J., Bissell, M. L., Budinčević, I., Day Goodacre, T., de Groote, R. P., Fedosseev, V. N., Flanagan, K. T., Franchoo, S., Garcia Ruiz, R. F., Heylen, H., Li, R., Lynch, K. M., Marsh, B. A., Neyens, G., Rossel, R. E., Rothe, S., Stroke, H. H., Wendt, K. D. A., Wilkins, S. G., Yang, X. F., Institut de Physique Nucléaire d'Orsay (IPNO), and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)

Subjects
[PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex]
Abstract

International audience; Combined decay and laser spectroscopy measurements of the isotope Fr214 are reported, using the collinear resonance ionization spectroscopy (CRIS) technique at the ISOLDE facility at CERN. For the Iπ=(1−) spin assignment, the g-factor value of g(Fr214)=+0.241(16) corresponds to a relatively pure (π1h9/2 ⊗ ν2g9/2) ground-state configuration. An alternative interpretation with g(Fr214)=+0.144(10), for a (2−) spin assignment suggests a greater contribution of configuration mixing with the ν1i11/2 orbital. As the N=126 shell closure is passed, a kink is observed at the δ⟨r2⟩213,214 value, which is analogous to the behavior observed in the neighboring isotopic chains.

Published
2016
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6. Combined high-resolution laser spectroscopy and nuclear decay spectroscopy for the study of the low-lying states in 206Fr, 202At, and 198Bi

Author

Lynch, K. M., Cocolios, T. E., Billowes, J., Bissell, M. L., Budinčević, I., Day Goodacre, T., De Groote, R. P., Farooq-Smith, G. J., Fedosseev, V. N., Flanagan, K. T., Franchoo, S., Garcia Ruiz, R. F., Heylen, H., Li, R., Marsh, B. A., Neyens, G., Rossel, R. E., Rothe, S., Stroke, H. H., Wendt, K. D. A., Wilkins, S. G., Yang, X., Institut de Physique Nucléaire d'Orsay (IPNO), and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)

Subjects
Physics::Atomic and Molecular Clusters, Nuclear Physics - Experiment, Physics::Atomic Physics, Physics::Chemical Physics, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment
Abstract

High-resolution laser spectroscopy was performed on $^{206}$Fr with the collinear resonance ionization spectroscopy (CRIS) experiment at CERN-ISOLDE. The hyperfine structure and isotope shift of the ground, first isomeric and second isomeric states were measured. The hyperfine components were unambiguously assigned to each nuclear state by means of laser-assisted nuclear decay spectroscopy. The branching ratios in the α decay of $^{206}$Fr and $^{202}$At were also measured for the first time with isomerically purified beams. The extracted hindrance factors allow determination of the spin of the ground, first isomeric, and second isomeric states in $^{202}$At and $^{198}$Bi.

Published
2016
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7. Decay-assisted collinear resonance ionization spectroscopy: Application to neutron-deficient francium

Author

Lynch, K. M., Billowes, J., Bissell, M. L., Budinčević, I., Cocolios, T. E., De Groote, R. P., De Schepper, S., Fedosseev, V. N., Flanagan, K. T., Franchoo, S., Ruiz, R. F. Garcia, Heylen, H., Marsh, B. A., Neyens, G., Procter, T. J., Rossel, R. E., Rothe, S., Strashnov, I., Stroke, H. H., Wendt, K. D. A., Institut de Physique Nucléaire d'Orsay (IPNO), and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)

Subjects
FOS: Physical sciences, Physics::Atomic Physics, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment (nucl-ex), Nuclear Experiment
Abstract

This paper reports on the hyperfine-structure and radioactive-decay studies of the neutron-deficient francium isotopes $^{202-206}$Fr performed with the Collinear Resonance Ionization Spectroscopy (CRIS) experiment at the ISOLDE facility, CERN. The high resolution innate to collinear laser spectroscopy is combined with the high efficiency of ion detection to provide a highly-sensitive technique to probe the hyperfine structure of exotic isotopes. The technique of decay-assisted laser spectroscopy is presented, whereby the isomeric ion beam is deflected to a decay spectroscopy station for alpha-decay tagging of the hyperfine components. Here, we present the first hyperfine-structure measurements of the neutron-deficient francium isotopes $^{202-206}$Fr, in addition to the identification of the low-lying states of $^{202,204}$Fr performed at the CRIS experiment., Comment: Accepted for publication with Physical Review X

Published
2014
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