Latest content added for UNT Digital Library Collection: UNT Theses and Dissertationshttp://digital.library.unt.edu/explore/collections/UNTETD/browse/?fq=untl_institution:UNT&sort=default&fq=str_degree_department:Department+of+Physics2012-12-27T22:03:54-06:00UNT LibrariesThis is a custom feed for browsing UNT Digital Library Collection: UNT Theses and DissertationsA System for Measurement of Negative-Ion Charge-Exchange Cross Sections2012-10-12T10:26:10-05:00http://digital.library.unt.edu/ark:/67531/metadc108076/<p><a href="/ark:/67531/metadc108076/"><img alt="A System for Measurement of Negative-Ion Charge-Exchange Cross Sections" title="A System for Measurement of Negative-Ion Charge-Exchange Cross Sections" src="/ark:/67531/metadc108076/thumbnail/"/></a></p><p>A radio-frequency positive-ion source and a fifty-kilovolt linear accelerator were designed and constructed in order to produce sizable quantities of hydrogen, helium, nitrogen, neon, and argon. Plans were then made to equip this ion source with charge-exchange apparatus suitable for charge-exchange cross-sectional measurements. It is the purpose of this paper to present the design of the equipment and to present operational knowledge of the equipment and of ion beams which are producible.</p>Gamma Ray Response of a CsI(T1) Crystal to 14 Mev Neutrons2012-10-12T10:26:10-05:00http://digital.library.unt.edu/ark:/67531/metadc108020/<p><a href="/ark:/67531/metadc108020/"><img alt="Gamma Ray Response of a CsI(T1) Crystal to 14 Mev Neutrons" title="Gamma Ray Response of a CsI(T1) Crystal to 14 Mev Neutrons" src="/ark:/67531/metadc108020/thumbnail/"/></a></p><p>The purpose of this paper is to study the possible excited states in the nucleus of Cs133. At North Texas State College a 100-Kev Cockcroft-Walton accelerator has been constructed for use as a neutron source for exciting various nuclei and for studying the gamma spectra obtained to determine their energy levels.</p>Gamma Rays from Neutron Excitation of Cs1332012-10-12T10:26:10-05:00http://digital.library.unt.edu/ark:/67531/metadc108026/<p><a href="/ark:/67531/metadc108026/"><img alt="Gamma Rays from Neutron Excitation of Cs133" title="Gamma Rays from Neutron Excitation of Cs133" src="/ark:/67531/metadc108026/thumbnail/"/></a></p><p>This thesis explores gamma rays from neutron excitation of Cs133.</p>Quaternion Representation of Crystal Point Groups2012-10-12T10:26:10-05:00http://digital.library.unt.edu/ark:/67531/metadc108066/<p><a href="/ark:/67531/metadc108066/"><img alt="Quaternion Representation of Crystal Point Groups" title="Quaternion Representation of Crystal Point Groups" src="/ark:/67531/metadc108066/thumbnail/"/></a></p><p>The physical behavior of crystalline solids is very closely related to the internal symmetry of the crystal structure. For this reason it is desirable to represent mathematically this symmetry in such a way that the actual physical problems can be handled as they arise. In the case of this thesis the research has been guided by a list of desired properties for such a representation. No claim is made that the list is complete.</p>Variational Wave Function for Sodium2012-12-27T22:03:54-06:00http://digital.library.unt.edu/ark:/67531/metadc130344/<p><a href="/ark:/67531/metadc130344/"><img alt="Variational Wave Function for Sodium" title="Variational Wave Function for Sodium" src="/ark:/67531/metadc130344/thumbnail/"/></a></p><p>The practical method of applying the variation principle to the calculation of the energy of an atom demands a trial function which contains variable parameters. The previous work done using this approach was based on the use of some combination of hydrogenic wave functions containing parameters inserted in appropriate places. The present calculation of the energy of the eleven-electron atom has been brought about using this method.</p>Operation and Control of a Radiofrequency Ion Source2012-12-27T22:03:54-06:00http://digital.library.unt.edu/ark:/67531/metadc130340/<p><a href="/ark:/67531/metadc130340/"><img alt="Operation and Control of a Radiofrequency Ion Source" title="Operation and Control of a Radiofrequency Ion Source" src="/ark:/67531/metadc130340/thumbnail/"/></a></p><p>This thesis examines the operation and control of a radiofrequency ion source.</p>Neutron Density Depression Due to an Oblate Spheroidal Detector2012-12-27T22:03:54-06:00http://digital.library.unt.edu/ark:/67531/metadc130362/<p><a href="/ark:/67531/metadc130362/"><img alt="Neutron Density Depression Due to an Oblate Spheroidal Detector" title="Neutron Density Depression Due to an Oblate Spheroidal Detector" src="/ark:/67531/metadc130362/thumbnail/"/></a></p><p>In this paper, two projects have been undertaken. First, Workman's calculations have been checked to a higher degree of approximation to determine the accuracy of his method. Second, a new set of boundary conditions has been developed for obtaining solutions of the neutron diffusion equation which do not depend on the solution of the equation inside the detector.</p>Dynamical Friction Coefficients for Plasmas Exhibiting Non-Spherical Electron Velocity Distributions2012-12-27T22:03:54-06:00http://digital.library.unt.edu/ark:/67531/metadc130480/<p><a href="/ark:/67531/metadc130480/"><img alt="Dynamical Friction Coefficients for Plasmas Exhibiting Non-Spherical Electron Velocity Distributions" title="Dynamical Friction Coefficients for Plasmas Exhibiting Non-Spherical Electron Velocity Distributions" src="/ark:/67531/metadc130480/thumbnail/"/></a></p><p>This investigation is designed to find the net rate of decrease in the component of velocity parallel to the original direction of motion of a proton moving through an electron gas exhibiting a non-spherical velocity distribution.</p>Energy Losses of Protons Projected through a Plasma Due to Collisions with Electrons of the Plasma for a Variety of Non-Maxwellian Electron Velocity Distributions2012-12-27T22:03:54-06:00http://digital.library.unt.edu/ark:/67531/metadc130468/<p><a href="/ark:/67531/metadc130468/"><img alt="Energy Losses of Protons Projected through a Plasma Due to Collisions with Electrons of the Plasma for a Variety of Non-Maxwellian Electron Velocity Distributions" title="Energy Losses of Protons Projected through a Plasma Due to Collisions with Electrons of the Plasma for a Variety of Non-Maxwellian Electron Velocity Distributions" src="/ark:/67531/metadc130468/thumbnail/"/></a></p><p>The purpose of this thesis is to study energy losses suffered by protons in traversing a plasma through collision with the electrons of the plasma. For these electrons a variety of non-Maxwellian velocity distributions are assumed.</p>A Computer Analysis of Complex Gamma-Ray Spectra2012-12-27T22:03:54-06:00http://digital.library.unt.edu/ark:/67531/metadc130612/<p><a href="/ark:/67531/metadc130612/"><img alt="A Computer Analysis of Complex Gamma-Ray Spectra" title="A Computer Analysis of Complex Gamma-Ray Spectra" src="/ark:/67531/metadc130612/thumbnail/"/></a></p><p>The purpose of this investigation was to provide a method for determining the relative intensities of all gamma rays in a particular spectrum, and thereby determine the relative transition probabilities.</p>