{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/23958"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/23958","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"The U center in potassium bromide crystals","abstract":"The optical bleaching of the U band in potassium bromide crystals at 78°K has been investigated. The nature of the secondary bands, the U' and the Ul bands, was studied. The U' band consisted of component bands, including the a band which is due to exciton transitions near a negative ion vacancy. One component of the U' band is bleached readily in either of two ways: either by warming the crystal to lo6°K or by irradiating with monochromatic light in the Ul band. This component of the ut band was interpreted as due to exciton transitions near a negative ion vacancy perturbed by the proximity of a Ul center, that is, an interstitial hydride ion. The spectral distribution of quantum efficiency for conversion of U centers to negative ion vacancies at 78°K was measured and found to decrease by 4~ on the high energy side of the U band. The U band has a high energy shoulder and it is suggested that this high energy shoulder exhibits a lower quantum efficiency for the conversion than does the main U band.","abstract_html":"The optical bleaching of the U band in potassium bromide crystals at 78°K has been investigated. The nature of the secondary bands, the U' and the Ul bands, was studied. The U' band consisted of component bands, including the a band which is due to exciton transitions near a negative ion vacancy. One component of the U' band is bleached readily in either of two ways: either by warming the crystal to lo6°K or by irradiating with monochromatic light in the Ul band. This component of the ut band was interpreted as due to exciton transitions near a negative ion vacancy perturbed by the proximity of a Ul center, that is, an interstitial hydride ion. The spectral distribution of quantum efficiency for conversion of U centers to negative ion vacancies at 78°K was measured and found to decrease by 4~ on the high energy side of the U band. The U band has a high energy shoulder and it is suggested that this high energy shoulder exhibits a lower quantum efficiency for the conversion than does the main U band.","abstract_has_math":false,"creators":["Rockstad, Howard Kent"],"institution":null,"degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Physics","degree_department":null,"school":null,"contributors":["Maurer, R.J."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2011,"date_issued":"2011-05-19T14:34:07Z","date_published":"2011-05-19T14:34:07Z","updated_at":"2026-07-22T22:25:23Z","subjects":["U center","U band","potassium bromide crystals","secondary bands","exciton transitions","negative ion vacancy","interstitial hydride ion"],"languages":["en"],"rights":["1964 Howard Kent Rockstad"],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["6141334"],"render_values":[{"text":"6141334","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/23958","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Maurer, R.J."]},{"key":"dc:creator","label":"Author","values":["Rockstad, Howard Kent"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2011-05-19T14:34:07Z","10000-01-01","1964"]},{"key":"dc:type","label":"Dc Type","values":["Dissertation / Thesis","text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Physics"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D."]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["U center","U band","potassium bromide crystals","secondary bands","exciton transitions","negative ion vacancy","interstitial hydride ion"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["1964 Howard Kent Rockstad"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["6141334","http://hdl.handle.net/2142/23958"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["The optical bleaching of the U band in potassium bromide crystals at 78°K has been investigated. The nature of the secondary bands, the U' and the Ul bands, was studied. The U' band consisted of component bands, including the a band which is due to exciton transitions near a negative ion vacancy. One component of the U' band is bleached readily in either of two ways: either by warming the crystal to lo6°K or by irradiating with monochromatic light in the Ul band. This component of the ut band was interpreted as due to exciton transitions near a negative ion vacancy perturbed by the proximity of a Ul center, that is, an interstitial hydride ion. The spectral distribution of quantum efficiency for conversion of U centers to negative ion vacancies at 78°K was measured and found to decrease by 4~ on the high energy side of the U band. The U band has a high energy shoulder and it is suggested that this high energy shoulder exhibits a lower quantum efficiency for the conversion than does the main U band.","Submitted by Carolyn Mead (cmead2@illinois.edu) on 2011-05-19T14:34:07Z No. of bitstreams: 1 1964_rockstad.pdf: 4812644 bytes, checksum: 7da0842d6f5a84e7fbfcdfb1fb68c9ec (MD5)","Made available in DSpace on 2011-05-19T14:34:07Z (GMT). No. of bitstreams: 1 1964_rockstad.pdf: 4812644 bytes, checksum: 7da0842d6f5a84e7fbfcdfb1fb68c9ec (MD5) Previous issue date: 1964","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Carolyn Mead (cmead2@illinois.edu) on 2011-05-19T14:34:07Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:12:53-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: Thesis","Thesis","U of I Only"]},{"key":"dc:title","label":"Title","values":["The U center in potassium bromide crystals"]}]}],"canonical_facts":{"dc:contributor":["Maurer, R.J."],"dc:creator":["Rockstad, Howard Kent"],"dc:date":["2011-05-19T14:34:07Z","10000-01-01","1964"],"dc:description":["The optical bleaching of the U band in potassium bromide crystals at 78°K has been investigated. The nature of the secondary bands, the U' and the Ul bands, was studied. The U' band consisted of component bands, including the a band which is due to exciton transitions near a negative ion vacancy. One component of the U' band is bleached readily in either of two ways: either by warming the crystal to lo6°K or by irradiating with monochromatic light in the Ul band. This component of the ut band was interpreted as due to exciton transitions near a negative ion vacancy perturbed by the proximity of a Ul center, that is, an interstitial hydride ion. The spectral distribution of quantum efficiency for conversion of U centers to negative ion vacancies at 78°K was measured and found to decrease by 4~ on the high energy side of the U band. The U band has a high energy shoulder and it is suggested that this high energy shoulder exhibits a lower quantum efficiency for the conversion than does the main U band.","Submitted by Carolyn Mead (cmead2@illinois.edu) on 2011-05-19T14:34:07Z No. of bitstreams: 1 1964_rockstad.pdf: 4812644 bytes, checksum: 7da0842d6f5a84e7fbfcdfb1fb68c9ec (MD5)","Made available in DSpace on 2011-05-19T14:34:07Z (GMT). No. of bitstreams: 1 1964_rockstad.pdf: 4812644 bytes, checksum: 7da0842d6f5a84e7fbfcdfb1fb68c9ec (MD5) Previous issue date: 1964","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Carolyn Mead (cmead2@illinois.edu) on 2011-05-19T14:34:07Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:12:53-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: Thesis","Thesis","U of I Only"],"dc:identifier":["6141334","http://hdl.handle.net/2142/23958"],"dc:language":["en"],"dc:rights":["1964 Howard Kent Rockstad"],"dc:subject":["U center","U band","potassium bromide crystals","secondary bands","exciton transitions","negative ion vacancy","interstitial hydride ion"],"dc:title":["The U center in potassium bromide crystals"],"dc:type":["Dissertation / Thesis","text"],"thesis:degree_discipline":["Physics"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."]},"updated_at":"2026-07-22T22:25:23Z"}