{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/53539"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/53539","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"An absolute measurement of the photodisintegration of Helium-4","abstract":"A measurement of the differential cross section has been performed for the photodisintegration of ⁴He into a proton plus a triton. This reaction is highly sensitive to the electromagnetic currents in the nucleus which arise from the exchange of mesons between nucleons. The study of light nuclei such as ⁴He, whose nucleonic structure is the simplest, holds the promise of perfecting a microscopic theory of nuclear dynamics, in which nuclear structure and reactions are understood in terms of fundamental particle interactions. The measurement was performed with a tagged-photon beam, using a large solid-angle charged particle detector developed for this and other similar experiments. The measurement was performed within the photon energy range between 63 and 71 MeV, and divided into four energy bins of 2 MeV each. The measurement of the differential cross section was confined to the angular range 36°-141° in the center-of-mass reference frame. The total cross section was determined to within a total uncertainty of 5%. The angular distribution was fitted to an expansion of Legendre polynomials in cos <i>θ</i> including terms of order 0-3. This measurement is in agreement with a previous measurement, and improves on the precision of the total cross section from the previous measurement by a factor of 6. A comparison is made with several theoretical calculations, and a qualitative agreement is found. These data suggest refinements to these calculations, in order to account for the quantitative differences.","abstract_html":"A measurement of the differential cross section has been performed for the photodisintegration of ⁴He into a proton plus a triton. This reaction is highly sensitive to the electromagnetic currents in the nucleus which arise from the exchange of mesons between nucleons. The study of light nuclei such as ⁴He, whose nucleonic structure is the simplest, holds the promise of perfecting a microscopic theory of nuclear dynamics, in which nuclear structure and reactions are understood in terms of fundamental particle interactions. The measurement was performed with a tagged-photon beam, using a large solid-angle charged particle detector developed for this and other similar experiments. The measurement was performed within the photon energy range between 63 and 71 MeV, and divided into four energy bins of 2 MeV each. The measurement of the differential cross section was confined to the angular range 36°-141° in the center-of-mass reference frame. The total cross section was determined to within a total uncertainty of 5%. The angular distribution was fitted to an expansion of Legendre polynomials in cos &lt;i&gt;θ&lt;/i&gt; including terms of order 0-3. This measurement is in agreement with a previous measurement, and improves on the precision of the total cross section from the previous measurement by a factor of 6. A comparison is made with several theoretical calculations, and a qualitative agreement is found. These data suggest refinements to these calculations, in order to account for the quantitative differences.","abstract_has_math":false,"creators":["Jones, Richard Thurston"],"institution":"Virginia Polytechnic Institute and State University","degree_name":"Ph. D.","degree_level":"doctoral","degree_discipline":"Physics","degree_department":"Physics","school":null,"contributors":[],"advisors":[],"committee_chairs":["Jenkins, David A."],"committee_members":["Ritter, Alfred \"Jimmy\"","Mizutani, Tetsuro","Ficenec, John R.","Debevec, P.T.","Schutt, D."],"year":1988,"date_issued":"1988","date_published":"1988","updated_at":"2026-07-22T22:18:52Z","subjects":[],"languages":["en_US"],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/10919/53539","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Jenkins, David A."]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Ritter, Alfred \"Jimmy\"","Mizutani, Tetsuro","Ficenec, John R.","Debevec, P.T.","Schutt, D."]},{"key":"dc:contributor.department","label":"Department","values":["Physics"]},{"key":"dc:creator","label":"Author","values":["Jones, Richard Thurston"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2015-06-24T13:35:08Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2015-06-24T13:35:08Z"]},{"key":"dc:date.issued","label":"Date","values":["1988"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Polytechnic Institute and State University"]},{"key":"dc:type","label":"Dc Type","values":["Dissertation"]},{"key":"dc:type.dcmitype","label":"Dc Type Dcmitype","values":["Text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Physics"]},{"key":"thesis:degree_level","label":"Degree Level","values":["doctoral"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph. 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The study of light nuclei such as ⁴He, whose nucleonic structure is the simplest, holds the promise of perfecting a microscopic theory of nuclear dynamics, in which nuclear structure and reactions are understood in terms of fundamental particle interactions. The measurement was performed with a tagged-photon beam, using a large solid-angle charged particle detector developed for this and other similar experiments. The measurement was performed within the photon energy range between 63 and 71 MeV, and divided into four energy bins of 2 MeV each. The measurement of the differential cross section was confined to the angular range 36°-141° in the center-of-mass reference frame. The total cross section was determined to within a total uncertainty of 5%. The angular distribution was fitted to an expansion of Legendre polynomials in cos <i>θ</i> including terms of order 0-3. This measurement is in agreement with a previous measurement, and improves on the precision of the total cross section from the previous measurement by a factor of 6. A comparison is made with several theoretical calculations, and a qualitative agreement is found. These data suggest refinements to these calculations, in order to account for the quantitative differences."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Ph. D."]},{"key":"dc:format.mimetype","label":"Dc Format Mimetype","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["An absolute measurement of the photodisintegration of Helium-4"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Jenkins, David A."],"dc:contributor.committeemember":["Ritter, Alfred \"Jimmy\"","Mizutani, Tetsuro","Ficenec, John R.","Debevec, P.T.","Schutt, D."],"dc:contributor.department":["Physics"],"dc:creator":["Jones, Richard Thurston"],"dc:date.accessioned":["2015-06-24T13:35:08Z"],"dc:date.available":["2015-06-24T13:35:08Z"],"dc:date.issued":["1988"],"dc:description.abstract":["A measurement of the differential cross section has been performed for the photodisintegration of ⁴He into a proton plus a triton. This reaction is highly sensitive to the electromagnetic currents in the nucleus which arise from the exchange of mesons between nucleons. The study of light nuclei such as ⁴He, whose nucleonic structure is the simplest, holds the promise of perfecting a microscopic theory of nuclear dynamics, in which nuclear structure and reactions are understood in terms of fundamental particle interactions. The measurement was performed with a tagged-photon beam, using a large solid-angle charged particle detector developed for this and other similar experiments. The measurement was performed within the photon energy range between 63 and 71 MeV, and divided into four energy bins of 2 MeV each. The measurement of the differential cross section was confined to the angular range 36°-141° in the center-of-mass reference frame. The total cross section was determined to within a total uncertainty of 5%. The angular distribution was fitted to an expansion of Legendre polynomials in cos <i>θ</i> including terms of order 0-3. This measurement is in agreement with a previous measurement, and improves on the precision of the total cross section from the previous measurement by a factor of 6. A comparison is made with several theoretical calculations, and a qualitative agreement is found. These data suggest refinements to these calculations, in order to account for the quantitative differences."],"dc:description.degree":["Ph. D."],"dc:format.mimetype":["application/pdf"],"dc:identifier.uri":["http://hdl.handle.net/10919/53539"],"dc:language.iso":["en_US"],"dc:publisher":["Virginia Polytechnic Institute and State University"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:title":["An absolute measurement of the photodisintegration of Helium-4"],"dc:type":["Dissertation"],"dc:type.dcmitype":["Text"],"thesis:degree_discipline":["Physics"],"thesis:degree_level":["doctoral"],"thesis:degree_name":["Ph. 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