rdf-syntax-grammar
mods:
  schema location: http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
  title info:
    non sort: The
    title: Beta-Delayed Proton and Gamma Decay of 27P
  name:
    name part: Simmons, Ellen Nicole
    role:
      role term: creator
    role:
      role term: author.
  name:
    name part: Tribble, Robert E.
    role:
      role term: thesis advisor.
  name:
    name part: Texas A & M University
    role:
      role term: degree granting institution.
  type of resource: text
  genre: bibliography
  origin info:
    place:
      place term: txu
    date issued: 2014
    issuance: monographic
  language:
    language term: eng
  physical description:
    form: remote
    extent: 1 online resource.
  abstract: The first and one of the most well observed gamma-ray lines in the interstellar medium was that of 1.809 MeV that comes from the β-decay of the ground state of ^(26)Al to excited states in its daughter (^(26)Mg), which then undergoes gamma decay. Since the half-life of ^(26)Al (7.2 x 105 yr) is much less than the time elapsed from the formation of the solar system (4.57 x 10^(9) years ago), its presence is a clear indication of ongoing nucleosynthesis in the Milky Way. The creation and destruction sites of ^(26)Al is still under debate, but is thought to be produced mainly in Wolf-Rayet (WR) stars. The destruction of ^(26)Al can be accomplished by proton capture on either the ground state or the metastable-state, the later is the one studied in this thesis. Energetically speaking, stars are too cold to study their reaction rates directly, that is, the actual cross sections are too low to allow us to measure them easily in the lab. So, an indirect method is required to gain the necessary information. In the case of interest, the indirect method used was the study of β-delayed γ and proton decay. The direct method involves a proton tunneling through the Coulomb barrier of ^(26m)Al to form excited states in ^(27)Si, which then decay through γ-emission. The indirect method starts with ^(27)P, which then β-decays to the same excited states in ^(27)Si (due to selection rules). The states that are populated above the proton threshold (E^(*) > S_(p) + E(0^(+)) = 7.463 + 0.228 = 7.691 MeV) can then decay by proton emission to ^(26m)Al. These states represent the resonances of interest in the direct proton capture process. While no new proton lines were observed, because the region of interest was dominated by the β-background, a slightly higher total proton branching ratio was estimated (0.155(3)% - 0.163(3)%). There was, however, a noticeable 'bulge' in the energy region around 300-400 keV, suggesting that there is potentially valuable information yet to be properly identif…
  note: by Ellen Simmons.
  note: "Major Subject: Physics"
  note: Includes vita.
  note: Doctor of Philosophy Texas A & M University 2013 http://hdl.handle.net/1969.1/151944
  note: Includes bibliographical references.
  note: Text (Dissertation)
  subject:
    topic: Major Physics
  subject:
    topic: 27P
  subject:
    topic: Nuclear Astrophysics
  identifier: http://hdl.handle.net/1969.1/151944
  record info:
    record content source: TXA
    record creation date: 140602
    record change date: 20151206101256.0
    record identifier: in00003454591
    language of cataloging:
      language term: eng