Source: Dissertation Abstracts International, Volume: 37-12, Section: B, page: 6204. / Thesis (Ph.D.)--The Florida State University, 1976.

Source: Dissertation Abstracts International, Volume: 38-08, Section: B, page: 3748. / Thesis (Ph.D.)--The Florida State University, 1977.

Source: Dissertation Abstracts International, Volume: 35-02, Section: B, page: 0983. / Thesis (Ph.D.)--The Florida State University, 1973.

Source: Dissertation Abstracts International, Volume: 35-10, Section: B, page: 5043. / Thesis (Ph.D.)--The Florida State University, 1974.

Neste trabalho estudamos a dependência do calibre nos cálculos modelo do fator de forma transverso elétrico para núcleos complexos. Foram consideradas as diferentes prescrições que procuram levar parcialmente em consideração os efeitos da corrente de dois corpos, no cálculo do fator de forma transverso elétrico, através dos vínculos impostos pela equação da continuidade. Quando os estados nucleares satisfazem a equação de Schrödinger e a corrente a equação da continuidade as prescrições coincidem. Entretanto, em geral, essas condições não são satisfeitas, surgindo assim as diferenças entre elas, que pode ser interpretada como uma dependência do calibre no cálculo do fator de forma transverso elétrico, Nosso objetivo neste trabalho é mostrar a importância, em núcleos complexos) da dependência do calibre oriunda da violação da equação de Schrödinger pelas funções de onda modelo. Nós fazemos uma análise para verificar sua origem e, para demonstrar sua importância quantitativa, comparamos cálculos do fator de forma na TDA e na RPA, para estados coletivos de paridade negativa no 16 ANTPOT O e 40 ANTPOT Ca. Esta comparação mostra uma considerável diminuição da dependência do calibre quando passamos da TDA para RPA. / In this work we study the gauge dependence of mode) calculations of transverse electric form factors in complex nuclei. We consider the different prescriptions that try to take partially into account the effects of the two-body current, in the calculation of the transverse electric form factor, through the continuity equation constraints. When the nuclear states obey the Schrodinger equation and the current density the continuity equation, the prescriptions coincide. However, in general, these two conditions are not satisfied and therefore they differ which can be seen as a gauge dependence in the calculation of the transverse electric form factor. Our aim is to show the importance in complex nuclei, of the gauge dependence that comes from the violation of the Schrödinger equation by the model wave functions. We perform an analysis to identify its origin and, to give evidences of its quantitative importance, we compare TDA and RPA calculations of transverse electric form factors for collective states of negative parity in 160 and 46Ca. This comparison shows that the gauge dependence diminishes considerably in RPA.

As estruturas dos núcleos de ANTPOT. 105 Rhe de ANTPOT 108.Pd foram estudadas usando a reação ANTPOT. 100 Mo(ANTPOT. 11 Bxalfaypzn) na energia incidente de 43 MeV. Foram realizadas as medidas de coincidências gama-gama, gama-gama- multiplicidade de partículas carregadas e das correlações angulares utilizando o espectrômetro gama formado por 4 detectores HPGe e o sistema ancilar de detectores de partículas carregadas. No núcleo de ANTPOT. 105 Rh foi observada pela primeira vez a banda gama, indicando a existência de trixialidade em baixo spin, e uma nova estrutura baseada no orbital intruso (431)1/2 POT. +. Duas estruturas formadas por uma quasi-próton, pig IND. 9/2 e pi[301]1/2 POT. -, foram estendidas, e em ambos casos foram observadas as duas signatures. Quatro bandas de dipolo magnético foram observadas em alto spin, sendo três delas de paridade negativa e com características similares: muito regulares, alinhamento quase constante e valores de B(M1)/B(E2) relativamente grandes. Duas destas bandas são aproximadamente degeneradas em energia de excitação, e podem ser consideradas como parceiras quirais com uma configuração pig IND. 9/2 vh IND. 11/2 v(g IND. 7/2, d IND. 5/2). No núcleo de ANTPOT. 108 Pd foram observadas pela primeira vez as duas signatures da banda de configuração negativa vh IND. 11/2 v(g IND. 7/2, d IND. 5/2), e uma banda com intensidade relativa baixa, à qual pode ser atribuída uma configuração de paridade positiva (vh IND. 11/2) POT. 2. A interpretação dos resultados experimentais foi feita no contexto de Cranked Shell Model e de Total Routhian Surfaces. / The structures of the 105Rh and 108Pd nuclei have been studied by the in-beam heavy-ion fusion-evaporation reaction 100Mo (11B, xaypzn) at 43 MeV incident energy. -, charged particle -- coincidences and angular correlation were measured using the spectrometer formed by four HPGe detectors and the charge-particle ancillary detector system. In 105Rh, a -vibration band was observed for the first time indicating the existence of triaxiality at low spin. A new structure based on the intruder [431]1/2+ próton orbital was identified. The structures based on one quase-proton, g9/2 and [301]1/2-, were extended, showing the two signatures partners. Four magnetic dipole bands have also been observed at high spin, three of which have negative parity and have similar characteristics: they are very regular, present nearly Constant alignments, and large values of B (M1)/B(E2) ratios. Two of them are nearly degenerate in excitation energy and could be chiral partners with , g9/2 x h 11/2 x (9 7/2 , d 5/2) configuration. Also, in 108Pd the both signatures partners of h 11/2 x (9 7/2 , d 5/2) configuration and one structure for the first time. Experimental results were interpreted within the framework of Cranked Shell Model and Total Routhian Surfaces.

Thesis (Ph.D.)--Boston University / A matrix version of Hartree-Fock self-consistent-field calculation is applied to O^16 and O^15 nuclei. The two-body interaction operator employed has a Serber exchange character with repulsive core and tensor component. A projection operator technique has been used to construct 1/S wave functions from the various excited configurations which interact with the ground state. The configuration interaction calculation gives the ground state energy of O^16 to be -129.91 mev, neglecting the coulomb forces, which contribute 18.24 mev. An attempt is made to perturb the shell model ground state wave function by mixing d orbital with occupied p orbital and f orbital with occupied s orbital, but it turned out that no such mixing occurs. The p(3/2) - p(1/2) splitting in O^15 nucleus due to the tensor force is estimated to be 4.05 mev, but the calculation puts the P(3/2) level lower than the p(1/2) level

The level structure and lifetimes of excited states in $\sp{81}$Sr were investigated using the techniques of inbeam $\gamma$ ray spectroscopy. The reactions $\sp{56}$Fe($\sp{28}$Si,2pn)$\sp{81}$Sr and $\sp{55}$Mn($\sp{29}$Si,p2n)$\sp{81}$Sr were used at beam energies of 103.6 and 95.2 MeV, respectively. The targets consisted of 0.1 mm thick natural Fe (92% $\sp{56}$Fe abundance) and $\simeq$ 2 mg/cm$\sp2$ $\sp{55}$Mn evaporated on a thick lead backing. / The previously known level scheme was confirmed and a total of 15 new levels were placed in $\sp{81}$Sr. Tentative spin assignments were based on level systematics, directional correlations between $\gamma$ rays and effective level lifetimes. / The mean lifetimes of 12 states were measured and lifetime limits were assigned for 10 others using the Doppler shift attenuation method. The deformation properties of states in $\sp{81}$Sr were determined from the lifetimes and compared to the deformations inferred from level energies. / The four rotational band structures in $\sp{81}$Sr were found to have differing deformations which persist to high spins. The magnitude of this deformation ranges from $\beta$ $\simeq$ 0.2 to $\simeq$ 0.4. Band crossings in the moderately deformed g$\sb{9/2}$ yrast and K = 5/2$\sp-$ bands were observed and a very deformed K = 1/2$\sp{(+)}$ band was seen up to a tentative spin of 31/2$\hbar$. / The experimental results were compared to theoretical projected and deformed shell model calculations. The crossing observed in the yrast band has been attributed to the alignment of two g$\sb{9/2}$ protons. The properties of the K = 1/2$\sp{(+)}$ band are shown to be consistent with a configuration based on a d$\sb{5/2}$ "intruder" orbital. This is the first nucleus in the mass 80 region to exhibit such a strongly deformed band based on this configuration. / Source: Dissertation Abstracts International, Volume: 49-03, Section: B, page: 0805. / Major Professor: Samuel L. Tabor. / Thesis (Ph.D.)--The Florida State University, 1988.

The level structure of $\sp{83}$Zr was investigated via the fusion-evaporation reaction $\sp{54}$Fe($\sp{32}$S,2pn)$\sp{83}$Zr at beam energies between 105 and 120 MeV using in-beam $\gamma$-ray spectroscopy techniques. $\gamma$ transitions from the decay of $\sp{83}$Zr were unambiguously identified by means of recoil-$\gamma$ and neutron-$\gamma$ coincidence experiments. The decay scheme was constructed on the basis of Compton suppressed $\gamma$-$\gamma$ coincidences, delayed $\gamma$-$\gamma$ coincidences and angular distribution measurements. A total of 34 transitions were identified connecting 26 new energy levels and the previously known ground state. The lifetimes of two low-lying isomeric states were determined. / A decoupled positive parity band built on the odd $g\sb{9/2}$ neutron configuration was observed up to spin 37/2 $\hbar$ with the first band crossing due to proton alignment showing a sharp backbend at $\hbar\omega$ $\approx$ 0.5 MeV. A strongly coupled negative parity band based on a 5/2$\sp-$ bandhead was observed up to spin 35/2 $\hbar$. The angular momentum alignment is discussed and compared to neighboring nuclei. A theoretical analysis was performed using the Woods-Saxon cranking model. The results of the calculation are consistent with the experimental findings for $\sp{83}$Zr and its neighbors. Triaxial shapes are predicted for all observed bands in $\sp{83}$Zr. At higher angular momenta a transition to well deformed prolate bands including the $h\sb{11/2}$ intruder orbitals is expected. / Source: Dissertation Abstracts International, Volume: 49-03, Section: B, page: 0804. / Major Professor: Samuel L. Tabor. / Thesis (Ph.D.)--The Florida State University, 1987.

A microscopic study of nucleon elastic scattering from the light non-zero spin nuclei $\sp{6,7}$Li, $\sp9$Be, and $\sp{10,11}$B is performed utilizing target densities constructed to be consistent with the known electro-weak data. The isospin character of the quadrupole distributions of these nuclei is further specified by analysis of inelastic quadrupole transitions in these systems where appropriate. The microscopic formalism associated with electron-nucleus elastic scattering and required to exactly treat nuclear elastic scattering from non-spherical nuclei is developed and the connection to the distorted wave approximation (DWA) is made. Both exact and DWA solutions for the cross section and analyzing power for the elastic scattering of protons from these nuclei are executed using energy and density dependent effective nucleon-nucleon interactions. The incident proton energy is generally chosen to correspond to the energy of representative data sets in the range of 20 MeV to 200 MeV. The non-spherical potentials associated with these nuclei are shown to be the dominant feature observed by the scattering experiments in some energy-momentum regimes and non-negligible in all cases. The distorted wave approximation is shown to be quite reliable for intermediate energy proton elastic scattering. Additionally the non-locality inherent in the single nucleon knockout exchange amplitudes is formally expanded as a series in the velocity dependence of the target densities. The convergence properties of this series are shown to be appropriate for the analysis of nucleon nucleus scattering at these energies, and approximations to the terms in this series are developed. / Source: Dissertation Abstracts International, Volume: 49-03, Section: B, page: 0802. / Major Professor: Fred Petrovich. / Thesis (Ph.D.)--The Florida State University, 1987.