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Direct reactions with exotic beams and polarized lithium beamsRoeder, Brian T. Kemper, Kirby W. January 1900 (has links)
Thesis (Ph. D.)--Florida State University, 2006. / Advisor: Kirby Kemper, Florida State University, College of Arts and Sciences, Dept. of Physics. Title and description from dissertation home page (viewed Sept. 21, 2006). Document formatted into pages; contains x, 124 pages. Includes bibliographical references.
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Production of nuclei near the neutron drip-line by projectile fragmentationKwan, Elaine. January 2006 (has links)
Thesis (Ph. D.)--Michigan State University. Dept. of Physics and Astronomy, 2006. / Title from PDF t.p. (viewed on Nov. 20, 2008) Includes bibliographical references (p. 124-130). Also issued in print.
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Exotic nuclei and relativistic mean-field theoryRutel, Bonnie Gwen. Piekarewicz, Jorge. January 2004 (has links)
Thesis (Ph. D.)--Florida State University, 2004. / Advisor: Dr. Jorge Piekarewicz, Florida State University, College of Arts and Sciences, Dept. of Physics. Title and description from dissertation home page (viewed June 15, 2004). Includes bibliographical references.
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Breakup of three-body exotic nuclei / Dissociation de noyaux exotiques à trois corpsPinilla Beltran, Edna Carolina 18 December 2012 (has links)
Le but principal de ma thèse de doctorat est d’étudier la dissociation de noyaux exotiques. Ces noyaux sont peu liés et présentent une structure en halo dominante. Ceci conduit à des propriétés très particulières, telles que des rayons beaucoup plus grands que ceux des noyaux voisins. Les noyaux 6He et 11Li sont des exemples typiques, et sont décrits par des structures alpha+n+n et 9Li+n+n, respectivement. La principale technique expérimentale pour étudier ces noyaux consiste à développer des faisceaux d’ions radioactifs, et à mesurer la section efficace de dissociation sur des cibles lourdes. Les données expérimentales nécessitent donc le développement de modèles théoriques précis pour leur interprétation.<p><p>Mon travail a consisté en le développement de la méthode eikonale pour décrire les processus de diffusion élastique et de dissociation. Cette méthode nécessite les fonctions d’onde du projectile qui, dans le cas présent, est décrit par une structure à trois corps. Cette situation rend les calculs particulièrement difficiles, en particulier pour la réaction de dissociation où les fonctions d’onde du continu à trois corps sont nécessaires. Les fonctions d’onde à trois corps sont décrites dans le cadre des coordonnées hypersphériques, à la fois pour les états liés et pour les états de diffusion.<p><p>J'ai d'abord calculé les sections efficaces de dissociation de 6He en utilisant des fonctions d'onde & / Doctorat en Sciences / info:eu-repo/semantics/nonPublished
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Polarizability effects due to low-energy enhancement of the gamma-strength functionNgwetsheni, Cebo January 2018 (has links)
>Magister Scientiae - MSc / Physics is the study of natural phenomena. Nuclear physicists have since the
discovery of the nucleus been working on understanding its dynamics. The nuclear
chart, analogous to the periodic table of elements, is illustrated in Fig. 1.1
and color coded according to decay modes. Several theoretical models, based
on various hypothesis, have been developed during the years in order to understand
nuclear phenomena such as nucleon-nucleon (n-n) interactions, binding
energies, radii, excited states, etc. Unfortunately, no-unique model is actually
able to grasp all nuclear phenomena at the desired level of accuracy.
Among the di erent models, we notice that two distinct hypotheses can be used
to describe nuclear properties. Firstly, the independent particle shell model
(IPSM) + the n-n residual interaction, which assumes that a nucleon moves
independently in a potential generated by other nucleons. Secondly, the macroscopic
models, where a nucleus is considered as a whole, i.e. neutrons and protons
behave cooperatively and are mutually coupled to each other; highlighting
the short-ranged character of the nuclear force. The liquid-drop model is an example
of such macroscopic models. Re nement of these models is dependent on
experimental observations that are better detailed for nuclei along the line of -
stability, making up a small fraction of the known isotopes, as shown in Fig. 1.1.
In practice, various techniques for studying exotic nuclei up to neutron and
proton drip-lines have been devised, including the use of radioactive ion beams.
However, the main challenges are the synthesization and short lived periods
of these exotic nuclei resulting in insu cient data collection from which the
characteristics and structural information are extracted. In general, nuclei have
unique structures represented by a particular con guration as given by the shell
model (SM). These structures impact a number of physical quantities, e.g. transition
probabilities, cross sections and photon-strength functions. Experimental
methods such as Coulomb excitation or electromagnetic radiation are used to
probe these structures without invoking the nuclear force.
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Produção de feixes radioativos ricos em nêutrons na região de massa A=10 a 15 / Production of neutron-rich radioactive beams in region of mass A=10 to 15Scotton, George Abud 26 April 2017 (has links)
Investigação da estrutura de núcleos exóticos é uma área bastante ativa da Física Nuclear atual. O desenvolvimento dessa área foi acentuado com a possibilidade de uso de feixes radioativos. Inspirados nessa possibilidade, laboratórios espalhados pelo mundo estão se desenvolvendo para produzir feixes radioativos de núcleos cada vez mais ricos em prótons ou em nêutrons. O uso de elementos radioativos como feixes têm oferecido oportunidades novas e únicas para pesquisa em física nuclear. Questões fundamentais tais como qual a natureza da matéria nuclear e como elementos pesados são sintetizados em novas, supernovas e estrelas de nêutrons podem ser abordadas em investigações utilizando-se feixes radioativos. Neste trabalho abordamos a produção de alguns desses feixes na região de massa A=10 e 15, especificamente, 10Be, 12B, 14C e 15C. Descrevemos métodos de produção e aplicamos simulações para produção de feixes com esses núcleos. Abordamos as peculiaridades na produção de cada um deles com o intuito de produzir feixes o mais intenso e puros possíveis. Nas simulações utilizamos a plataforma Lise++ baseada em método de Monte Carlo e foi dada ênfase na utilização de um sistema de duplo-solenoides. As simulações foram comparadas com resultados experimentais obtidos com esse sistema para os feixes de 12B e 14C, onde um bom acordo foi obtido. / Nuclear Structure Investigations of exotic nuclei is currently a very active area of Nuclear Physics. Many laboratories around the world are developing their system to produce radioactive beams of nuclei rich in protons or neutrons. The use of these radioactive elements as beams has offered new and unique opportunities for research in nuclear physics. Fundamental questions such as what the nature of nuclear matter is and how heavy elements are synthesized in novae, supernovae and neutron stars can be addressed in investigations using radioactive beams. In this work we address the production of some of these beams in the region of mass A = 10 and 15, specifically 10Be, 12B e 14,15C. We describe production methods and apply simulations using the plataforma Lise++ with Monte Carlo method. We addressed the peculiarities related to the production of each of them, in the sense to get the most intense and pure secondary radioactive beams possible. In the simulations, emphasis was given to the use of a double-solenoid system. The simulations were compared with experimental results obtained with these systems for the 12B and 14C beams, where a good agreement was obtained.
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Calculation of observables in the nuclear 0s1d shell using new model-independent two-body interactions.Mkhize, Percival Sbusiso. January 2007 (has links)
<p><font face="TimesNewRomanPSMT">
<p align="left">The objective of the present investigation is to calculate observables using the nuclear shell model for a variety of nuclear phenomena and to make comparisons with experimental data as well as the older interaction. The shell-model code OXBASH was employed for the calculations. Quantities investigated include energy level schemes, static magnetic dipole and electric quadrupole moments, electromagnetic transition probabilities, spectroscopic factors and beta decay rates.</p>
</font></p>
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Calculation of observables in the nuclear 0s1d shell using new model-independent two-body interactions.Mkhize, Percival Sbusiso. January 2007 (has links)
<p><font face="TimesNewRomanPSMT">
<p align="left">The objective of the present investigation is to calculate observables using the nuclear shell model for a variety of nuclear phenomena and to make comparisons with experimental data as well as the older interaction. The shell-model code OXBASH was employed for the calculations. Quantities investigated include energy level schemes, static magnetic dipole and electric quadrupole moments, electromagnetic transition probabilities, spectroscopic factors and beta decay rates.</p>
</font></p>
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Universalidade em sistemas de 3 e 4 bósonsVentura, Daneele Saraçol [UNESP] 30 March 2011 (has links) (PDF)
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ventura_ds_me_ift.pdf: 470589 bytes, checksum: 7a9dc11d67fbc536096e87c18acc1e7c (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Neste trabalho investigamos a universalidade em sistemas de três e quatro bósons através do cálculo das suas energias de ligação e dos raios quadráticos médios. Utilizando duas funções de escala calculadas com um potencial de alcance zero e um potencial de alcance finito corrigimos em primeira ordem em r0/a (r0 e a são, respectivamente, o alcance efetivo do potencial e o comprimento de espalhamento de dois corpos) o ponto onde os estados excitados de três corpos desaparecem. Estudamos também as estruturas dos estados de quatro corpos associados ao estado fundamental de três corpos para energia de dois corpos igual a zero. Esses estados são formados predominantemente por uma configuração do tipo 3+1. Os cálculos foram realizados no espaço das configurações usando um método variacional / In this work we investigated the universality in three- and four-boson systems calculating their energies and root-mean-square radii. Using two scaling functions calculated with a zero and a finite range potentials, we corrected to first order in r0/a (r0 and a are, respectively, the effective range of the potential and the two-body scattering length) the point where the three-body excited states disappear. We also studied the structures of the four-body statestied to the three-body ground state for a two-body energy equal zero. These states are predominantly composed by a 3+1 configuration. The calculations were performed in the configuration space using a variational method
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Universalidade em sistemas de 3 e 4 bósons /Ventura, Daneele Saraçol. January 2011 (has links)
Orientador: Marcelo Takeshi Yamashita / Banca: Tobias Frederico / Banca: Renato Higa / Resumo: Neste trabalho investigamos a universalidade em sistemas de três e quatro bósons através do cálculo das suas energias de ligação e dos raios quadráticos médios. Utilizando duas funções de escala calculadas com um potencial de alcance zero e um potencial de alcance finito corrigimos em primeira ordem em r0/a (r0 e a são, respectivamente, o alcance efetivo do potencial e o comprimento de espalhamento de dois corpos) o ponto onde os estados excitados de três corpos desaparecem. Estudamos também as estruturas dos estados de quatro corpos associados ao estado fundamental de três corpos para energia de dois corpos igual a zero. Esses estados são formados predominantemente por uma configuração do tipo 3+1. Os cálculos foram realizados no espaço das configurações usando um método variacional / Abstract: In this work we investigated the universality in three- and four-boson systems calculating their energies and root-mean-square radii. Using two scaling functions calculated with a zero and a finite range potentials, we corrected to first order in r0/a (r0 and a are, respectively, the effective range of the potential and the two-body scattering length) the point where the three-body excited states disappear. We also studied the structures of the four-body statestied to the three-body ground state for a two-body energy equal zero. These states are predominantly composed by a 3+1 configuration. The calculations were performed in the configuration space using a variational method / Mestre
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