Measurement of picosecond lifetimes in neutron-rich Xe isotopes

Background: Lifetimes of nuclear excited states in fission fragments have been studied in the past following isotope separation, thus giving access mainly to the fragments' daughters and only to long-lived isomeric states in the primary fragments. For the first time now, short-lived excited sta...

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Detalhes bibliográficos
Autores: Fraile Prieto, Luis Mario, Mach, H., Paziy, V.
Formato: artículo
Fecha de publicación:2016
País:España
Recursos:Universidad Complutense de Madrid (UCM)
Repositorio:Docta Complutense
Idioma:inglés
OAI Identifier:oai:docta.ucm.es:20.500.14352/18991
Acesso em linha:https://hdl.handle.net/20.500.14352/18991
Access Level:acceso abierto
Palavra-chave:539.1
Fission Fragments
Excited states
Nuclei.
Física nuclear
2207 Física Atómica y Nuclear
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oai_identifier_str oai:docta.ucm.es:20.500.14352/18991
network_acronym_str ES
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repository_id_str
spelling Measurement of picosecond lifetimes in neutron-rich Xe isotopesFraile Prieto, Luis MarioMach, H.Paziy, V.539.1Fission FragmentsExcited statesNuclei.Física nuclear2207 Física Atómica y NuclearBackground: Lifetimes of nuclear excited states in fission fragments have been studied in the past following isotope separation, thus giving access mainly to the fragments' daughters and only to long-lived isomeric states in the primary fragments. For the first time now, short-lived excited states in the primary fragments, produced in neutron-induced prompt fission of U-235 and Pu-241, were studied within the EXILL&FATIMA campaign at the intense neutron-beam facility of the Institute Laue-Langevin in Grenoble. Purpose: We aim to investigate the quadrupole collective properties of neutron-rich even-even Xe-138,Xe-140,Xe-142 isotopes lying between the double shell closure N = 82 and Z = 50 and a deformed region with octupole collectivity. Method: The gamma rays emitted from the excited fragments were detected with a mixed array consisting of 8 HPGe EXOGAM Clover detectors (EXILL) and 16 LaBr3(Ce) fast scintillators (FATIMA). The detector system has the unique ability to select the interesting fragment making use of the high resolution of the HPGe detectors and determine subnanosecond lifetimes using the fast scintillators. For the analysis the generalized centroid difference method was used. Results: We show that quadrupole collectivity increases smoothly with increasing neutron number above the closed N = 82 neutron shell. Our measurements are complemented by state-of-the-art theory calculations based on shell-model descriptions. Conclusions: The observed smooth increase in quadrupole collectivity is similar to the evolution seen in the measured masses of the xenon isotopic chain and is well reproduced by theory. This behavior is in contrast to higher Z even-even nuclei where abrupt change in deformation occurs around N = 90.American Physical SocietyUniversidad Complutense de Madrid20162016-09-0320162016-09-03journal articlehttp://purl.org/coar/resource_type/c_6501info:eu-repo/semantics/articleapplication/pdfhttps://hdl.handle.net/20.500.14352/18991reponame:Docta Complutenseinstname:Universidad Complutense de Madrid (UCM)Inglésengopen accesshttp://purl.org/coar/access_right/c_abf2info:eu-repo/semantics/openAccessoai:docta.ucm.es:20.500.14352/189912026-06-02T12:44:21Z
dc.title.none.fl_str_mv Measurement of picosecond lifetimes in neutron-rich Xe isotopes
title Measurement of picosecond lifetimes in neutron-rich Xe isotopes
spellingShingle Measurement of picosecond lifetimes in neutron-rich Xe isotopes
Fraile Prieto, Luis Mario
539.1
Fission Fragments
Excited states
Nuclei.
Física nuclear
2207 Física Atómica y Nuclear
title_short Measurement of picosecond lifetimes in neutron-rich Xe isotopes
title_full Measurement of picosecond lifetimes in neutron-rich Xe isotopes
title_fullStr Measurement of picosecond lifetimes in neutron-rich Xe isotopes
title_full_unstemmed Measurement of picosecond lifetimes in neutron-rich Xe isotopes
title_sort Measurement of picosecond lifetimes in neutron-rich Xe isotopes
dc.creator.none.fl_str_mv Fraile Prieto, Luis Mario
Mach, H.
Paziy, V.
author Fraile Prieto, Luis Mario
author_facet Fraile Prieto, Luis Mario
Mach, H.
Paziy, V.
author_role author
author2 Mach, H.
Paziy, V.
author2_role author
author
dc.contributor.none.fl_str_mv Universidad Complutense de Madrid
dc.subject.none.fl_str_mv 539.1
Fission Fragments
Excited states
Nuclei.
Física nuclear
2207 Física Atómica y Nuclear
topic 539.1
Fission Fragments
Excited states
Nuclei.
Física nuclear
2207 Física Atómica y Nuclear
description Background: Lifetimes of nuclear excited states in fission fragments have been studied in the past following isotope separation, thus giving access mainly to the fragments' daughters and only to long-lived isomeric states in the primary fragments. For the first time now, short-lived excited states in the primary fragments, produced in neutron-induced prompt fission of U-235 and Pu-241, were studied within the EXILL&FATIMA campaign at the intense neutron-beam facility of the Institute Laue-Langevin in Grenoble. Purpose: We aim to investigate the quadrupole collective properties of neutron-rich even-even Xe-138,Xe-140,Xe-142 isotopes lying between the double shell closure N = 82 and Z = 50 and a deformed region with octupole collectivity. Method: The gamma rays emitted from the excited fragments were detected with a mixed array consisting of 8 HPGe EXOGAM Clover detectors (EXILL) and 16 LaBr3(Ce) fast scintillators (FATIMA). The detector system has the unique ability to select the interesting fragment making use of the high resolution of the HPGe detectors and determine subnanosecond lifetimes using the fast scintillators. For the analysis the generalized centroid difference method was used. Results: We show that quadrupole collectivity increases smoothly with increasing neutron number above the closed N = 82 neutron shell. Our measurements are complemented by state-of-the-art theory calculations based on shell-model descriptions. Conclusions: The observed smooth increase in quadrupole collectivity is similar to the evolution seen in the measured masses of the xenon isotopic chain and is well reproduced by theory. This behavior is in contrast to higher Z even-even nuclei where abrupt change in deformation occurs around N = 90.
publishDate 2016
dc.date.none.fl_str_mv 2016
2016-09-03
2016
2016-09-03
dc.type.none.fl_str_mv journal article
http://purl.org/coar/resource_type/c_6501
dc.type.openaire.fl_str_mv info:eu-repo/semantics/article
format article
dc.identifier.none.fl_str_mv https://hdl.handle.net/20.500.14352/18991
url https://hdl.handle.net/20.500.14352/18991
dc.language.none.fl_str_mv Inglés
eng
language_invalid_str_mv Inglés
language eng
dc.rights.none.fl_str_mv open access
http://purl.org/coar/access_right/c_abf2
dc.rights.openaire.fl_str_mv info:eu-repo/semantics/openAccess
rights_invalid_str_mv open access
http://purl.org/coar/access_right/c_abf2
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
dc.publisher.none.fl_str_mv American Physical Society
publisher.none.fl_str_mv American Physical Society
dc.source.none.fl_str_mv reponame:Docta Complutense
instname:Universidad Complutense de Madrid (UCM)
instname_str Universidad Complutense de Madrid (UCM)
reponame_str Docta Complutense
collection Docta Complutense
repository.name.fl_str_mv
repository.mail.fl_str_mv
_version_ 1869403402746724352
score 15,301603

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