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16 results on '"A.V. Belozyorov"'

1. Shape coexistence and the N = 20 shell closure far from stability by inelastic scattering

Author

V. Lapoux, A. Gillibert, H. Savajols, J. M. Casandjian, A. Drouart, J. A. Scarpaci, C. E. Demonchy, Y. E. Penionzhkevich, Z. Dlouhý, F. Sarazin, W. Mittig, C. Jouanne, A.V. Belozyorov, D. Baiborodin, N. Alamanos, E. C. Pollacco, P. Roussel-Chomaz, J. Mrazek, A. Korichi, and S. M. Lukyanov

Subjects
Physics, Nuclear and High Energy Physics, education.field_of_study, 010308 nuclear & particles physics, Hadron, Population, Shell (structure), State (functional analysis), Inelastic scattering, 01 natural sciences, Stability (probability), medicine.anatomical_structure, 0103 physical sciences, medicine, Nuclear fusion, Atomic physics, 010306 general physics, education, Nucleus
Abstract

Following mass measurements in the region N = 20 and N = 28, we have studied inelastic nuclear scattering for the nuclei 34Si, 33Al and 32Mg. No evidence for a low-lying shape isomeric 0+ state was found in 34Si, and an upper limit for the population cross-section could be established, rendering its existence very unlikely. A new transition was found in 33Al, that is a good candidate for a 2p–2h state and therefore a determination of the 2p–2h gap at N = 20. Inelastic nuclear scattering strongly excites 3− states, as seen in 34Si. A strong transition was found in 32Mg that should correspond to the first 3− in this nucleus, lying very low as compared to theory and systematics in this region.

Published
2002

2. A determination of the interaction potential

Author

W. Mittig, A. de Vismes, A. Musumarra, N. K. Skobelev, F. Sarazin, W. N. Catford, A. Gillibert, V. Lapoux, N. Alamanos, P. Roussel-Chomaz, S. Ottini-Hustache, H. Savajols, A.V. Belozyorov, Alinka Lepine-Szily, F. Marie, A. Pakou, N. A. Orr, C. Borcea, F. Auger, J. Barrette, J. C. Angélique, M. D. Cortina-Gil, S. M. Lukyanov, F. de Oliveira, Z. Dlouhy, and Y. E. Penionzhkevich

Subjects
Physics, Nuclear and High Energy Physics, Hydrogen, 010308 nuclear & particles physics, chemistry.chemical_element, Halo nucleus, 01 natural sciences, 7. Clean energy, Cross section (physics), Interaction potential, Density distribution, chemistry, 0103 physical sciences, Transmission method, Atomic physics, Nuclear Experiment, 010306 general physics, Nucleon, Charge exchange
Abstract

The reaction cross section for the halo nucleus 6 He on hydrogen has been measured at 36 MeV/nucleon using the transmission method and a value of σ R =409±22 mb was obtained. A coherent analysis within a microscopic model of this result in conjunction with (p,p) and (p,n) angular distributions has allowed the interaction potential to be uniquely determined. This analysis also allowed the 6 He density distribution to be explored.

Published
2001

3. [Untitled]

Author

G. Auger, F. de Oliveira, A. Gillibert, W. Mittig, S. M. Lukyanov, N. A. Orr, F. Sarazin, D. Baiborodin, D. Ridikas, M. Lewitowicz, Oleg B. Tarasov, A.V. Belozyorov, C. Borcea, Z. Dlouhý, A. de Vismes, H. Savajols, Hiroyoshi Sakurai, A. S. Lalleman, Y. E. Penionzhkevich, F. Nowacki, P. Roussel-Chomaz, E. Caurier, and Zhongzhou Ren

Subjects
Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Nuclear Theory, Hadron, Shell (structure), Fermion, Condensed Matter Physics, 01 natural sciences, Atomic and Molecular Physics, and Optics, Baryon, Time of flight, Mean field theory, 0103 physical sciences, Physical and Theoretical Chemistry, Atomic physics, Nuclear Experiment, 010306 general physics, Nucleon, Ground state
Abstract

A mass measurement experiment by a time of flight method with the SPEG spectrometer at GANIL has been performed to investigate the N = 20 and N = 28 shell closures far from stability. The masses of 31 neutron-rich nuclei in the range A = 29–47 have been measured. The precision of 19 masses has been significantly improved and 12 masses were measured for the first time. The neutron-rich Cl, S and P isotopes are seen to exhibit a change in shell structure around N = 28. Comparison with shell model and relativistic mean field calculations demonstrate that the observed effects arise from deformed prolate ground state configurations associated with shape coexistence. The evidence of an isomeric state in the 43S and its interpretation by a shell model calculation confirm the analysis of the masses and constitutes the first evidence of the predicted shape coexistence around N = 28.

Published
2001

4. Shape Coexistence and theN=28Shell Closure Far from Stability

Author

M. Lewitowicz, F. Nowacki, H. Savajols, P. Roussel-Chomaz, G. Auger, A.V. Belozyorov, Hiroyoshi Sakurai, S. M. Lukyanov, F. de Oliveira, Zhongzhou Ren, A. S. Lalleman, N. A. Orr, C. Borcea, Z. Dlouhý, E. Caurier, D. Baiborodin, Oleg B. Tarasov, F. Sarazin, Y. E. Penionzhkevich, A. Gillibert, A. de Vismes, D. Ridikas, and W. Mittig

Subjects
Physics, Range (particle radiation), Isotope, 010308 nuclear & particles physics, Nuclear Theory, Closure (topology), Shell (structure), General Physics and Astronomy, Prolate spheroid, 01 natural sciences, Stability (probability), Molecular physics, Mean field theory, 0103 physical sciences, 010306 general physics, Ground state
Abstract

The masses of 31 neutron-rich nuclei in the range A = 29-47 have been measured. The precision of 19 masses has been significantly improved and 12 masses were measured for the first time. The neutron-rich Cl, S, and P isotopes are seen to exhibit a change in shell structure around N = 28. Comparison with shell model and relativistic mean field calculations demonstrate that the observed effects arise from deformed prolate ground state configurations associated with shape coexistence. Evidence for shape coexistence is provided by the observation of an isomer in 43S.

Published
2000

5. Spectroscopy of 13Be

Author

B. G. Novatskii, Z. Dlouhý, A.V. Belozyorov, J. Vincour, R. Kalpakchieva, Yu. E. Penionzhkevich, Alexander Ostrowski, M. von Lucke-Petsch, Sˇ. Piskorˇ, H. G. Bohlen, D.V. Alexandrov, E. Yu. Nikolskii, and D. N. Stepanov

Subjects
Nuclear reaction, Physics, Nuclear and High Energy Physics, Mass excess, Q value, Excited state, Atomic physics, Spectroscopy, Isotopes of beryllium, Ground state, Spectral line
Abstract

Six quasi-stationary states of 13 Be populated in the 14 C( 11 B, 12 N) 13 Be reaction at E lab = 190 MeV are reported. A Q -value = −39.60(9) MeV and a mass excess, M.E.= 33.95(9) MeV, have been found for the lowest observed spectral line. The ground state is unstable with respect to one-neutron emission by 0.80(9) MeV. Excitation energies of 1.22(10), 2.10(16), 4.14(12), 5.09(14) and 7.0(2) MeV have been obtained for the observed spectral lines.

Published
1998

6. A facility for the study of neutron-rich light nuclei

Author

Š. Piskoř, A.V. Belozyorov, V. E. Zhuchko, J. Vincour, Yu. E. Penionzhkevich, R. Kalpakchieva, and V. S. Salamatin

Subjects
Nuclear physics, Physics, Nuclear and High Energy Physics, Light nucleus, Range (particle radiation), Nuclear Theory, Ionization chamber, Neutron, Focal plane detector, Atomic physics, Nuclear Experiment, Instrumentation, Spectrograph
Abstract

An experimental set-up designed for the investigation of light nuclei close to the neutron dripline is described. It is built on the basis of a broad range magnetic spectrograph having a focal plane detector consisting of a four-section ionization chamber and two position-sensitive proportional counters. The neutron-rich nuclei are studied in heavy-ion reactions at energies below 18 MeV/u.

Published
1998

7. Particle stability of the isotopesO26andNe32in the reaction 44 MeV/nucleonCa48+Ta

Author

F. Pougheon, R. Anne, J.C. Jacmart, C. Détraz, Yu. E. Penionzhkevich, W. D. Schmidt-Ott, E. Kashy, D. Guillemaud-Mueller, M. Lewitowicz, A.C. Mueller, Yu. S. Lyutostansky, P. Bricault, S. M. Lukyanov, A. Richard, A. G. Artuhk, M. V. Zverev, A.V. Belozyorov, Y. Zhang, A. Latimier, and D. Bazin

Subjects
Physics, Nuclear reaction, Nuclear and High Energy Physics, Isotope, 010308 nuclear & particles physics, Nuclear Theory, Particle stability, 7. Clean energy, 01 natural sciences, Isotopes of oxygen, 0103 physical sciences, Particle, Atomic physics, Nuclear Experiment, 010306 general physics, Nucleon, Radioactive decay, Order of magnitude
Abstract

An attempt has been made to synthesize the extremely neutron-rich isotope $^{26}\mathrm{O}$ in the nuclear reaction 44 MeV/nucleon $^{48}\mathrm{Ca}$+n/rTa. Use was made of magnetic separation and identification methods including time-of-flight and \ensuremath{\Delta}E,E measurements. The $^{26}\mathrm{O}$ nucleus appears to be unstable against particle emission since no events attributable to the $^{26}\mathrm{O}$ nucleus were observed at a level one order of magnitude lower than that predicted from the extrapolated yields. The previously unobserved isotope $^{32}\mathrm{Ne}$ was found to be particle stable and the isotope $^{31}\mathrm{Ne}$ particle unstable. Neutron-separation energies calculated with different models are tabulated.

Published
1990

8. Interaction potential and reaction cross section of neutron rich nuclei on protons

Author

N. Alamanos, C. Borcea, A. Gillibert, F. Auger, M-D. Cortina-Gil, F. de Oliveira, A. Pakou, Alinka Lepine-Szily, N. K. Skobelev, V. Lapoux, P. Roussel-Chomaz, D. Hirata, A. Musumarra, J-C. Angélique, W. Mittig, Eric Bauge, J. Barrette, S. M. Lukyanov, Y. E. Penionzhkevich, H. Savajols, N. A. Orr, Z. Dlouhy, A.V. Belozyorov, F. Carstoiu, W. N. Catford, S. Ottini, F. Marie, A. de Vismes, F. Sarazin, and J-P. Delaroche

Subjects
Nuclear physics, Physics, Cross section (physics), Interaction potential, Proton, Nuclear Theory, Neutron, Nuclear cross section, Nuclear Experiment
Abstract

Proton reaction cross sections were measured on various stable and exotic nuclei, aiming at a better understanding of the potential for neutron rich nuclei.

Published
2003

9. INTERACTION POTENTIAL AND REACTION CROSS SECTION OF NEUTRON RICH NUCLEI ON PROTONS

Author

A. Pakou, F. de Oliveira, V. Lapoux, D. Hirata, H. Savajols, F. Sarazin, A. Musumarra, N. Alamanos, J. C. Angélique, W. Mittig, N. A. Orr, J. Barrette, F. Auger, S. M. Lukyanov, A. de Vismes, N. K. Skobelev, A. Gillibert, P. Roussel-Chomaz, C. Borcea, Y. E. Penionzhkevich, Z. Dlouhy, F. Carstoiu, F. Marie, W. N. Catford, S. Ottini, Alinka Lepine-Szily, M.D. Cortina-Gil, E. Bauge, A.V. Belozyorov, and J. P. Delaroche

Subjects
Nuclear physics, Physics, Cross section (physics), Interaction potential, Neutron
Published
2002

10. Proton reaction cross-section measurements on stable and neutron-rich nuclei as a probe of the nucleon-nucleus interaction

Author

N. Alamanos, F. Marie, A. Gillibert, J. P. Delaroche, F. Carstoiu, J. C. Angélique, P. Roussel-Chomaz, N. A. Orr, A. de Vismes, Michel Girod, S. M. Lukyanov, F. Sarazin, N. K. Skobelev, M. D. Cortina-Gil, E. Bauge, F. Auger, Alinka Lepine-Szily, F. de Oliveira, A. Pakou, W. N. Catford, J. Barrette, A.V. Belozyorov, D. Hirata, W. Mittig, S. Ottini-Hustache, Y. E. Penionzhkevich, Z. Dlouhy, C. Borcea, H. Savajols, A. Musumarra, V. Lapoux, Grand Accélérateur National d'Ions Lourds (GANIL), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), 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)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Proton, Hydrogen, h-1(alpha, x), (na-28, x), (li-8, x), 01 natural sciences, 7. Clean energy, (mg-31, x), finite nuclei, (na-29, x), (mg-30, x), approximation, (li-9, x), optical-model analysis, Physics, (ne-25, x), consistent, (ne-24, x), potentials, medicine.anatomical_structure, isospin dependence, e approximate to 35-81 mev/nucleon, Atomic physics, Nucleon, (li-7, x), (be-9, x), (ne-23, x), (mg-32, x), inelastic-scattering, Nuclear and High Energy Physics, (he-6, x), (f-21, x), chemistry.chemical_element, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear physics, Cross section (physics), (mg-29, x), 0103 physical sciences, medicine, (f-22, x), comparison with model predictions, Neutron, elastic-scattering, (na-25, x), 010306 general physics, isotopes, (be-10, x), (na-26, x), 010308 nuclear & particles physics, Attenuation, (f-23, x), (be-11, x), (ne-26, x), radii, measured reaction sigma, (na-27, x), chemistry, (f-24, x), Nucleus
Abstract

Proton reaction cross-section measurements on various stable and neutron-rich nuclei (He-4,He-6, Li7-9, Be9-11, F21-24, N22-26, Na25-29 and Mg29-32) were performed via the attenuation method at intermediate energies (similar to 35-75 A MeV) and using a cryogenic hydrogen target. The results are discussed in the framework of different approaches of the nucleon-nucleus potential. (C) 2002 Elsevier Science B.V. All rights reserved. Nuclear Physics A

Published
2002

11. Some regularities in the production of isotopes in

Author

V. D. Toneev, Yu. E. Penionzhkevich, M. G. Saint-Laurent, A.V. Belozyorov, Z. Dlouhy, R. Anne, D. Baiborodin, C. Borcea, D. Guillemaud-Mueller, W. Trinder, Oleg B. Tarasov, R. Kalpakchieva, A.C. Mueller, M. Lewitowicz, Yu. Ts. Oganessian, O. Sorlin, S. M. Lukyanov, V. Z. Maidikov, and N. K. Skobelev

Subjects
Nuclear physics, Nuclear reaction, Range (particle radiation), Mass excess, Isotope, Chemistry, Nucleosynthesis, Mass spectrum, Nuclear binding energy, Atomic physics, Spectral line
Published
1998

12. Persistence of the

Author

M. Lewitowicz, N. A. Orr, F. de Oliveira, Y. E. Penionzhkevich, H. Savajols, C. Borcea, S. M. Lukyanov, D. Ridikas, A. Gillibert, G. Auger, A. de Vismes, Hiroyoshi Sakurai, A.V. Belozyorov, A. S. Lalleman, W. Mittig, D. Baiborodin, P. Roussel-Chomaz, and F. Sarazin

Subjects
0303 health sciences, Chemistry, 030303 biophysics, Hadron, Fermion, Nuclear physics, Baryon, 03 medical and health sciences, Mass spectrum, Neutron, Isotopes of silicon, Atomic physics, Nucleon, Isotopes of magnesium, 030304 developmental biology
Abstract

The masses of 16 neutron-rich nuclei in the mass range from 35 to 45 have been measured using a direct time of flight technique following the fragmentation of a 48Ca beam at 60 MeV/nucleon. The masses of 35,36Mg, 38Al, 39,40Si, 42,43P and 43,44S are reported for the first time. Preliminary analysis shows that the N=28 shell closure persists, even if weakened by the large neutron excess.

Published
1998

13. New mass measurements of neutron-rich nuclei near N = 20

Author

S. M. Lukyanov, Christoph A. Stephan, G. Audi, M. Lewitowicz, A.V. Belozyorov, Yu. E. Penionzhkevich, A. Cunsolo, W. Mittig, N. A. Orr, L. Bianchi, L.K. Fifield, Zhan Wen Long, Y. Schutz, E. Plagnol, A. Gillibert, Antonio Villari, A. Foti, L. Tassan-Got, 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), Grand Accélérateur National d'Ions Lourds (GANIL), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse (CSNSM), 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), Institut de Physique Nucléaire d'Orsay (IPNO), 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), Normandie Université (NU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Island of inversion, SHELL model, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Nuclear physics, Fragmentation (mass spectrometry), 0103 physical sciences, Neutron, Atomic physics, 010306 general physics, Nucleon
Abstract

The masses of 39 neutron-rich nuclei in the mass range 17–37 have been measured using a direct time-of-flight technique following the fragmentation of a 48 Ca beam at 55 MeV/nucleon. The masses of 29,30 Ne, 34,35 Mg and 36,37 Al are reported for the first time. The very neutron-rich nuclei, 31–33 Na, are found to be 2–4 MeV less bound than previously believed. A comparison is made with recently available large scale shell model calculations encompassing the deformed A ∼32 nuclei. Conclusions are drawn regarding the extent of the region of deformation, which is found to include 30 Ne.

Published
1991

14. First observation of the neutron-rich nuclei42Si,45, 46P,48S, and51Cl from the interaction of 44 MeV/u48Ca +64Ni

Author

D. Bazin, S. M. Lukyanov, Yu. E. Penionzhkevich, W. D. Schmidt-Ott, M. Lewitowicz, A. Latimier, A. Richard, R. Anne, F. Pougheon, Y. Zhang, D. Guillemaud-Mueller, C. Détraz, E. Kashy, A.V. Belozyorov, A. G. Artukh, J.C. Jacmart, A.C. Mueller, P. Bricault, Grand Accélérateur National d'Ions Lourds (GANIL), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire d'Orsay (IPNO), 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), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), 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, Nuclear and High Energy Physics, Isotope, 010308 nuclear & particles physics, Elementary particle, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, 3. Good health, Nuclear physics, 0103 physical sciences, Nuclear fusion, Neutron, 010306 general physics, Beam (structure)
Abstract

Five new very neutron-rich isotopes, 42Si,45,46p, 48 S and 51CI, are identiled from the interaction of a 44 MeV/b 48Ca beam with a 64Ni target.

Published
1990

15. Measurement and QRPA calculation of the beta-delayed neutron emission of $^{21-22}$N and $^{23-24}$O

Author

A. G. Artukh, J.C. Jacmart, A.V. Belozyorov, A. Richard, D. Guillemaud-Mueller, A.C. Mueller, Yu. E. Penionzhkevich, W. D. Schmidt-Ott, D. Bazin, R. Anne, H.V. Klapdor-Kleingrothaus, M. Lewitowicz, F. Pougheon, A. Staudt, C. Détraz, S. M. Lukyanov, P. Bricault, E. Kashy, Institut de Physique Nucléaire d'Orsay (IPNO), 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), Grand Accélérateur National d'Ions Lourds (GANIL), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), 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 Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Nuclear and High Energy Physics, Isotope, Spectrometer, 010308 nuclear & particles physics, Neutron emission, Astrophysics::High Energy Astrophysical Phenomena, Nuclear Theory, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, 7. Clean energy, Isotopes of nitrogen, Nuclear physics, Decay energy, 0103 physical sciences, Neutron detection, Atomic physics, Nuclear Experiment, 010306 general physics, Delayed neutron, Radioactive decay
Abstract

Neutron-rich isotopes of nitrogen and oxygen have been produced as projectile-like fragments in the reaction of a 44 MeV/u 48 Ca beam with a 173mg/cm 2 181 Ta target. The fragments have been analyzed by the doubly achromatic spectrometer LISE and implanted in a semiconductor identification telescope, surrounded by a 4π neutron detector in order to observe their radioactive decay. The β-delayed neutron emission has been measured for the isotopes 21,22 N and 23,24 O for the first time and the β-half-lives T 1 2 and delayed neutron-emission probabilities P n are determined. These values are discussed within the framework of a QRPA calculation. The influence of the decay energy Q β used in the calculation is examined, indicating the reliability of predicted matrix elements. Furthermore, P n values are calculated and compared to the experimental data.

Published
1990

16. Search for the tri- and tetra-neutron in reactions induced by 11B and 9Be ions on 7Li

Author

C. Borcea, Z. Dlouhý, Yu. E. Penionzhkevich, A.M. Kalinin, A.V. Belozyorov, and Nguyen Hoai Chau

Subjects
Nuclear reaction, Physics, Nuclear and High Energy Physics, biology, Bound state, Tetra, Physical chemistry, Neutron, Heavy ion, Atomic physics, biology.organism_classification, Spectral line, Ion
Abstract

In three different heavy ion reactions the energy spectra of the 14 O, 15 O and 12 N nuclei have been measured to obtain some information about their partners in the exit channel - the multineutron systems 4 n and 3 n. No evidence for the existence of any bound state in the multineutron systems has been obtained at the cross section level of 1 nb/MeV · sr achieved in the experiment. The phase-space analysis has given no positive results concerning the existence of quasistationary states in the 4 n and 3 n systems either.

Published
1988

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