{"id":{"repo_id":"must-thes","oai_identifier":"oai:scholarsmine.mst.edu:doctoral_dissertations-2981"},"canonical_url":"https://search.dev.ndltd.org/etd/must-thes/oai:scholarsmine.mst.edu:doctoral_dissertations-2981","repository":{"repo_id":"must-thes","name":"Missouri University of Science and Technology","base_url":"https://scholarsmine.mst.edu/do/oai/"},"display":{"title":"The lifetime and effective quenching cross section of the 6²P₃/₂ state of thallium","abstract":"\"The measurement of the lifetime of the metastable 6²P₃/₂ state of thallium is discussed. Measurement of time varying optical absorption by time sampling techniques is explained for the study of the decay of the metastable atom concentration following a pulsed radio frequency discharge. The decay of the thallium radiation from optically allowed states terminating on the metastable state is measured at nine different thallium densities in the afterglow of the discharge. This radiation repopulates the metastable state and is displayed on an oscilloscope. The metastable lifetime is measured as a function of the thallium density at three different r-f power levels and by two modes of operation. At high thallium densities where thallium collisions control the diffusion of the metastable atoms, the lifetime measurements yielded a thallium diffusion cross section for the 6²P₃/₂ state of 100 ± 30 c 10 ⁻¹⁶ cm² and an effective self quenching cross section of 5.4 ± 0.5 x 10⁻¹⁶ cm²\"--page [i].","abstract_html":""The measurement of the lifetime of the metastable 6²P₃/₂ state of thallium is discussed. Measurement of time varying optical absorption by time sampling techniques is explained for the study of the decay of the metastable atom concentration following a pulsed radio frequency discharge. The decay of the thallium radiation from optically allowed states terminating on the metastable state is measured at nine different thallium densities in the afterglow of the discharge. This radiation repopulates the metastable state and is displayed on an oscilloscope. The metastable lifetime is measured as a function of the thallium density at three different r-f power levels and by two modes of operation. At high thallium densities where thallium collisions control the diffusion of the metastable atoms, the lifetime measurements yielded a thallium diffusion cross section for the 6²P₃/₂ state of 100 ± 30 c 10 ⁻¹⁶ cm² and an effective self quenching cross section of 5.4 ± 0.5 x 10⁻¹⁶ cm²"--page [i].","abstract_has_math":false,"creators":["Pickett, Robert Charles"],"institution":"University of Missouri--Rolla","degree_name":"Ph. D. in Physics","degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2016,"date_issued":"2016-02-10T08:00:00Z","date_published":"2016-02-10T08:00:00Z","updated_at":"2026-07-24T03:18:50Z","subjects":["Physics"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://scholarsmine.mst.edu/doctoral_dissertations/1979","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Pickett, Robert Charles"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.available","label":"Dc Date Available","values":["2016-02-10T08:00:00Z"]},{"key":"dc:type","label":"Dc Type","values":["Dissertation - Open Access"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph. D. in Physics"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Missouri--Rolla"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Physics"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://scholarsmine.mst.edu/doctoral_dissertations/1979"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["\"The measurement of the lifetime of the metastable 6²P₃/₂ state of thallium is discussed. Measurement of time varying optical absorption by time sampling techniques is explained for the study of the decay of the metastable atom concentration following a pulsed radio frequency discharge. The decay of the thallium radiation from optically allowed states terminating on the metastable state is measured at nine different thallium densities in the afterglow of the discharge. This radiation repopulates the metastable state and is displayed on an oscilloscope. The metastable lifetime is measured as a function of the thallium density at three different r-f power levels and by two modes of operation. At high thallium densities where thallium collisions control the diffusion of the metastable atoms, the lifetime measurements yielded a thallium diffusion cross section for the 6²P₃/₂ state of 100 ± 30 c 10 ⁻¹⁶ cm² and an effective self quenching cross section of 5.4 ± 0.5 x 10⁻¹⁶ cm²\"--page [i]."]},{"key":"dc:title","label":"Title","values":["The lifetime and effective quenching cross section of the 6²P₃/₂ state of thallium"]}]}],"canonical_facts":{"dc:creator":["Pickett, Robert Charles"],"dc:date.available":["2016-02-10T08:00:00Z"],"dc:description.abstract":["\"The measurement of the lifetime of the metastable 6²P₃/₂ state of thallium is discussed. Measurement of time varying optical absorption by time sampling techniques is explained for the study of the decay of the metastable atom concentration following a pulsed radio frequency discharge. The decay of the thallium radiation from optically allowed states terminating on the metastable state is measured at nine different thallium densities in the afterglow of the discharge. This radiation repopulates the metastable state and is displayed on an oscilloscope. The metastable lifetime is measured as a function of the thallium density at three different r-f power levels and by two modes of operation. At high thallium densities where thallium collisions control the diffusion of the metastable atoms, the lifetime measurements yielded a thallium diffusion cross section for the 6²P₃/₂ state of 100 ± 30 c 10 ⁻¹⁶ cm² and an effective self quenching cross section of 5.4 ± 0.5 x 10⁻¹⁶ cm²\"--page [i]."],"dc:identifier":["https://scholarsmine.mst.edu/doctoral_dissertations/1979"],"dc:subject":["Physics"],"dc:title":["The lifetime and effective quenching cross section of the 6²P₃/₂ state of thallium"],"dc:type":["Dissertation - Open Access"],"thesis:degree_name":["Ph. D. in Physics"],"thesis:institution_name":["University of Missouri--Rolla"]},"updated_at":"2026-07-24T03:18:50Z"}