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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Accurate Mass Measurements: Identifying Known Unknowns Using Publically Accessible Databases

Little, J., Brown, Stacy D., Cleven, C. 01 May 2010 (has links)
No description available.
2

Fenomenologia de medidas diretas de massa de neutrino / Neutrino mass direct measurement phenomenology

Salgado, Maurílio Ferreira 07 May 2010 (has links)
Orientador: Orlando Luís Goulart Peres / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Física Gleb Wataghin / Made available in DSpace on 2018-08-15T20:53:54Z (GMT). No. of bitstreams: 1 Salgado_MaurilioFerreira_M.pdf: 1919300 bytes, checksum: 5f4341c064eb9c9bbcc9a3ae84fa84d8 (MD5) Previous issue date: 2010 / Resumo: A massa é um dos objetos de estudo mais importantes em física de neutrinos, talvez o mais importante. Nesta dissertação discutimos como se dá a geração de massa no Modelo Padrão, que é capaz de explicar de maneira compacta grande parte da diversidade dos fenômenos observados em física de partículas. Nele o neutrino é previsto como uma partícula sem massa. Na sequência discorremos sobre a oscilação, atualmente quase unânime na comunidade científica, e como a hipótese de oscilação de neutrinos implica a existência da massa do neutrino (divergindo do Modelo Padrão) e estudamos as possibilidades de o neutrino ser uma partícula de Dirac ou Majorana. Por fim, dedicamos atenção ao fenômeno de duplo decaimento beta, que é uma tentativa de identificar qual tipo de partícula é o neutrino, e especialmente ao KATRIN (Karlsruhe Tritium Neutrino Experiment) que visa à determinação da escala absoluta de massa dos neutrinos através do espectro do elétron no decaimento beta do trítio. Nesse reproduzimos a sensibilidade esperada (0:2eV) por um método independente e testamos, para quatro neutrinos misturados e massivos, como o espectro se modifica e se o experimento conseguiria discriminar esse caso, o que se mostrou inviável / Abstract: The mass is one of the most important study subjects in neutrino physics, if not the most important. In this dissertation we discuss how mass is generated in the Standard Model, which explains in a compact way almost all of the observed phenomena diversity in particle physics. It forcasts a massless neutrino. Following we expatiate on neutrino oscilations, almost unanimous in the scientific community nowadays, and argue how the neutrino oscilation hypothesis implies the existence of neutrino mass (diverging of Standard Model) and study the possibilities that the neutrino could be a Dirac or Majorana particle. Lastly, we devote attention to the double beta decay experiment, which is a trial in identifing which particle the neutrino is, and specialy to KATRIN (Karlsruhe Tritium Neutrino Experiment) which aims the determination of the neutrino mass scale using the electron spectra in tritium beta decay. In this one we reproduce the expected sensitivity (0:2eV) by an independent method and test, for four mixed and massive neutrinos, how the spectrum modifies and if the experiment could differentiate this case, which proved impracticable / Mestrado / Física / Mestre em Física
3

The TITAN electron beam ion trap: assembly, characterization, and first tests

Froese, Michael Wayne 19 September 2006 (has links)
The precision of mass measurements in a Penning trap is directly proportional to an ion's charge state and can be increased by using highly charged ions (HCI) from an Electron Beam Ion Trap (EBIT). By bombarding the injected and trapped singly charged ions with an intense electron beam, the charge state of the ions is rapidly increased. To use this method for short-lived isotopes, very high electron beam current densities are required of the TITAN EBIT, built and commissioned at the Max-Planck-Institute for Nuclear Physics in Heidelberg, Germany and transported to TRIUMF for the TITAN on-line facility. This EBIT has produced charge states as high as Kr34+ and Ba54+ with electron beams of up to 500 mA and 27 keV. Once the EBIT is operational at full capacity (5 A, 60 keV), most species can be bred into a He-like configuration within tens of ms. / October 2006
4

The TITAN electron beam ion trap: assembly, characterization, and first tests

Froese, Michael Wayne 19 September 2006 (has links)
The precision of mass measurements in a Penning trap is directly proportional to an ion's charge state and can be increased by using highly charged ions (HCI) from an Electron Beam Ion Trap (EBIT). By bombarding the injected and trapped singly charged ions with an intense electron beam, the charge state of the ions is rapidly increased. To use this method for short-lived isotopes, very high electron beam current densities are required of the TITAN EBIT, built and commissioned at the Max-Planck-Institute for Nuclear Physics in Heidelberg, Germany and transported to TRIUMF for the TITAN on-line facility. This EBIT has produced charge states as high as Kr34+ and Ba54+ with electron beams of up to 500 mA and 27 keV. Once the EBIT is operational at full capacity (5 A, 60 keV), most species can be bred into a He-like configuration within tens of ms.
5

The TITAN electron beam ion trap: assembly, characterization, and first tests

Froese, Michael Wayne 19 September 2006 (has links)
The precision of mass measurements in a Penning trap is directly proportional to an ion's charge state and can be increased by using highly charged ions (HCI) from an Electron Beam Ion Trap (EBIT). By bombarding the injected and trapped singly charged ions with an intense electron beam, the charge state of the ions is rapidly increased. To use this method for short-lived isotopes, very high electron beam current densities are required of the TITAN EBIT, built and commissioned at the Max-Planck-Institute for Nuclear Physics in Heidelberg, Germany and transported to TRIUMF for the TITAN on-line facility. This EBIT has produced charge states as high as Kr34+ and Ba54+ with electron beams of up to 500 mA and 27 keV. Once the EBIT is operational at full capacity (5 A, 60 keV), most species can be bred into a He-like configuration within tens of ms.
6

Mass measurements of neutron-rich strontium and rubidium isotopes in the A ≈ 100 and development of an electrospray ionization ion source / Mesures de masses d'isotropes de strontium et rubidium riches en neutrons dans la région A ≈ 100 et développement d'une source d'ions à ionisation electrospray

De roubin, Antoine 22 December 2016 (has links)
Une extension de la surface de masses atomiques dans la région A ≈ 100 est présentée par l’intermédiaire des mesures de masse des isotopes 100-102Sr et 100-102Rb. Les mesures ont été effectuées avec le spectromètre de masse ISOLTRAP constitué de différents pièges à ions. Les premières mesures directes des masses des 100-102Sr et du 100-102Rb sont rapportées ici. Ces mesures confirment la continuité de la région de déformation nucléaire avec l’augmentation du nombre de neutrons jusqu’à N = 65.De sorte à interpréter la déformation dans la chaine isotopique du strontium et à déterminer si une déformation peut apparaitre pour des isotopes de krypton plus lourds, une comparaison est faite entre les données expérimentales et des résultats de calculs théoriques disponibles dans la littérature. Pour compléter ces comparaisons, des calculs Hartree-Fock-Bogoliubov pour des isotopes pairs et impairs sont aussi présentés, illustrant la compétition entre formes nucléaires dans la région.Le développement d’une source d’ions à ionisation par électro nébuliseur est présenté. Cette source peut produire un large panel de masses isobariques destinées à la calibration. La première mise en service de la source est présentée, incluant les résultats des premiers balayages en masse détectés derrière le spectromètre de masse quadripolaire. Une résolution de quelques unités de masses atomiques a été atteinte. / An extension of the atomic mass surface in the region A ≈ 100 is performed via massmeasurements of the 100-102Sr and 100-102Rb isotopes with the ion-trap mass spectrometer ISOLTRAPat CERN-ISOLDE. The first direct mass measurements of 102Sr and 101;102Rb are reported here. Thesemeasurements confirm the continuation of the region of nuclear deformation with the increase of neutronnumber, at least as far as N = 65.In order to interpret the deformation in the strontium isotopic chain and to determine whether an onsetof deformation is present in heavier krypton isotopes, a comparison is made between experimentalvalues and theoretical calculations available in the literature. To complete this comparison, Hartree-Fock-Bogoliubov calculations for even and odd isotopes are also presented, illustrating the competitionof nuclear shapes in the region.The development of an electrospray ionization ion source is presented. This source can delivera large range of isobaric masses for calibration purposes. The early commissioning of the sourceis discussed, including the results from the first mass scans detected behind the quadrupole massspectrometer. A resolution of a few atomic mass units is reached.

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