{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/90736"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/90736","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Supersonic cooling of short-lived molecular states in a pulsed microcavity plasma jet","abstract":"\"Electronic states of helium diners having potential energy > 24 eV and radiative lifetimes as short as 19 ns have been generated in a micro-plasma jet at super-atmospheric pressure and rotationally cooled by supersonic expansion. Spatial-temporal spectrograms of d^3Σ+u→(b^3)π_g (v', v\"\") = (0, 0) emission are obtained, which contain the information about the dynamic cooling process during the molecular beam expansion. Analysis shows the spatial-temporal evolution of the rotational temperature to be a damped sinusoid that reaches a minimum value of 100 K, which is attributed to the reflection of electrons from a virtual cathode located downstream of the jet nozzle. Data fitting to the damped sinusoid function yields a spatially-averaged electron density of 10^8 cm^(-3). The experimental setup has the potential to be used in exploration of the spectroscopy and plasma dynamics in various gas molecules.\"","abstract_html":""Electronic states of helium diners having potential energy > 24 eV and radiative lifetimes as short as 19 ns have been generated in a micro-plasma jet at super-atmospheric pressure and rotationally cooled by supersonic expansion. Spatial-temporal spectrograms of d^3Σ+u→(b^3)π_g (v', v"") = (0, 0) emission are obtained, which contain the information about the dynamic cooling process during the molecular beam expansion. Analysis shows the spatial-temporal evolution of the rotational temperature to be a damped sinusoid that reaches a minimum value of 100 K, which is attributed to the reflection of electrons from a virtual cathode located downstream of the jet nozzle. Data fitting to the damped sinusoid function yields a spatially-averaged electron density of 10^8 cm^(-3). The experimental setup has the potential to be used in exploration of the spectroscopy and plasma dynamics in various gas molecules."","abstract_has_math":false,"creators":["Su, Rui"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"M.S.","degree_level":"Thesis","degree_discipline":"Electrical & Computer Engr","degree_department":null,"school":null,"contributors":["Eden, James G."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2016,"date_issued":"2016-07-07T20:27:05Z","date_published":"2016-07-07T20:27:05Z","updated_at":"2026-07-22T22:26:34Z","subjects":["microplasma","supersonic cooling","molecular spectroscopy"],"languages":["en"],"rights":["Copyright 2016 Rui Su"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/2142/90736","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Eden, James G."]},{"key":"dc:creator","label":"Author","values":["Su, Rui"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2016-07-07T20:27:05Z","2018-07-08T09:15:16Z","2016-04-05","2016-05"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Electrical & Computer Engr"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["M.S."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["microplasma","supersonic cooling","molecular spectroscopy"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2016 Rui Su"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/90736"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["\"Electronic states of helium diners having potential energy > 24 eV and radiative lifetimes as short as 19 ns have been generated in a micro-plasma jet at super-atmospheric pressure and rotationally cooled by supersonic expansion. Spatial-temporal spectrograms of d^3Σ+u→(b^3)π_g (v', v\"\") = (0, 0) emission are obtained, which contain the information about the dynamic cooling process during the molecular beam expansion. Analysis shows the spatial-temporal evolution of the rotational temperature to be a damped sinusoid that reaches a minimum value of 100 K, which is attributed to the reflection of electrons from a virtual cathode located downstream of the jet nozzle. Data fitting to the damped sinusoid function yields a spatially-averaged electron density of 10^8 cm^(-3). The experimental setup has the potential to be used in exploration of the spectroscopy and plasma dynamics in various gas molecules.\"","Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2018-05-01","The student, Rui Su, accepted the attached license on 2016-04-04 at 13:18.","The student, Rui Su, submitted this Thesis for approval on 2016-04-04 at 13:33.","This Thesis was approved for publication on 2016-04-05 at 14:40.","DSpace SAF Submission Ingestion Package generated from Vireo submission #9145 on 2016-07-07 at 13:48:50","Made available in DSpace on 2016-07-07T20:27:05Z (GMT). No. of bitstreams: 2 SU-THESIS-2016.pdf: 1330263 bytes, checksum: 1855fc35e52938a88f222f956c9b89df (MD5) LICENSE.txt: 4203 bytes, checksum: 2209ef670402f17dd9f4e5aa51577c6d (MD5) Previous issue date: 2016-04-05","Embargo set by: Seth Robbins for item 93088 Lift date: 2018-07-07T20:28:14Z Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD system","Embargo set by: Seth Robbins for item 93088 Lift date: 2018-07-07T20:35:34Z Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD system","U of I Only Restriction Lifted for Item 93088 on 2018-07-08T09:15:16Z."]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Supersonic cooling of short-lived molecular states in a pulsed microcavity plasma jet"]}]}],"canonical_facts":{"dc:contributor":["Eden, James G."],"dc:creator":["Su, Rui"],"dc:date":["2016-07-07T20:27:05Z","2018-07-08T09:15:16Z","2016-04-05","2016-05"],"dc:description":["\"Electronic states of helium diners having potential energy > 24 eV and radiative lifetimes as short as 19 ns have been generated in a micro-plasma jet at super-atmospheric pressure and rotationally cooled by supersonic expansion. Spatial-temporal spectrograms of d^3Σ+u→(b^3)π_g (v', v\"\") = (0, 0) emission are obtained, which contain the information about the dynamic cooling process during the molecular beam expansion. Analysis shows the spatial-temporal evolution of the rotational temperature to be a damped sinusoid that reaches a minimum value of 100 K, which is attributed to the reflection of electrons from a virtual cathode located downstream of the jet nozzle. Data fitting to the damped sinusoid function yields a spatially-averaged electron density of 10^8 cm^(-3). The experimental setup has the potential to be used in exploration of the spectroscopy and plasma dynamics in various gas molecules.\"","Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2018-05-01","The student, Rui Su, accepted the attached license on 2016-04-04 at 13:18.","The student, Rui Su, submitted this Thesis for approval on 2016-04-04 at 13:33.","This Thesis was approved for publication on 2016-04-05 at 14:40.","DSpace SAF Submission Ingestion Package generated from Vireo submission #9145 on 2016-07-07 at 13:48:50","Made available in DSpace on 2016-07-07T20:27:05Z (GMT). No. of bitstreams: 2 SU-THESIS-2016.pdf: 1330263 bytes, checksum: 1855fc35e52938a88f222f956c9b89df (MD5) LICENSE.txt: 4203 bytes, checksum: 2209ef670402f17dd9f4e5aa51577c6d (MD5) Previous issue date: 2016-04-05","Embargo set by: Seth Robbins for item 93088 Lift date: 2018-07-07T20:28:14Z Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD system","Embargo set by: Seth Robbins for item 93088 Lift date: 2018-07-07T20:35:34Z Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD system","U of I Only Restriction Lifted for Item 93088 on 2018-07-08T09:15:16Z."],"dc:format":["application/pdf"],"dc:identifier":["http://hdl.handle.net/2142/90736"],"dc:language":["en"],"dc:rights":["Copyright 2016 Rui Su"],"dc:subject":["microplasma","supersonic cooling","molecular spectroscopy"],"dc:title":["Supersonic cooling of short-lived molecular states in a pulsed microcavity plasma jet"],"dc:type":["text"],"thesis:degree_discipline":["Electrical & Computer Engr"],"thesis:degree_level":["Thesis"],"thesis:degree_name":["M.S."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:26:34Z"}