{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/23931"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/23931","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Ionospheric Simulator (IonSim): Simulating Ionospheric conditions in a vacuum chamber","abstract":"Understanding and improving ionospheric models is important for both military and civilian purposes. This understanding improves prediction of radio propagation used for communication and GPS navigation. Various space-borne instruments, such as retarding potential analyzers (RPAs) and ion traps are routinely flown in low earth orbit (LEO) to provide data for seeding/improve ionospheric models. This thesis describes and characterizes a new ion source that can be used to test and calibrate these space-borne instruments inside a laboratory vacuum chamber. Hot filaments are used to thermionically emit electrons inside the source. These electrons collisionally ionize neutral particles inside the source. Guided by ion-optics simulations, the ion and the electron trajectories inside the source are controlled to provide the required ion beams. A detailed description of the control electronics and the embedded controller for electron emission is discussed within. Using the custom made electronics, the source is able to provide an ion beam with current densities and mean energy comparable to the conditions in LEO.","abstract_html":"Understanding and improving ionospheric models is important for both military and civilian purposes. This understanding improves prediction of radio propagation used for communication and GPS navigation. Various space-borne instruments, such as retarding potential analyzers (RPAs) and ion traps are routinely flown in low earth orbit (LEO) to provide data for seeding/improve ionospheric models. This thesis describes and characterizes a new ion source that can be used to test and calibrate these space-borne instruments inside a laboratory vacuum chamber. Hot filaments are used to thermionically emit electrons inside the source. These electrons collisionally ionize neutral particles inside the source. Guided by ion-optics simulations, the ion and the electron trajectories inside the source are controlled to provide the required ion beams. A detailed description of the control electronics and the embedded controller for electron emission is discussed within. Using the custom made electronics, the source is able to provide an ion beam with current densities and mean energy comparable to the conditions in LEO.","abstract_has_math":false,"creators":["Dhar, Saurav"],"institution":"Virginia Tech","degree_name":"Master of Science","degree_level":"masters","degree_discipline":"Electrical Engineering","degree_department":"Electrical and Computer Engineering","school":null,"contributors":[],"advisors":[],"committee_chairs":["Earle, Gregory D."],"committee_members":["Bailey, Scott M.","Baumann, William T."],"year":2013,"date_issued":"2013-10-29","date_published":"2013-10-29","updated_at":"2026-07-22T22:20:09Z","subjects":["Ion source","Ionosphere","vacuum chamber","Low Earth Orbit"],"languages":[],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["vt_gsexam:1742"],"render_values":[{"text":"vt_gsexam:1742","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10919/23931","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Earle, Gregory D."]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Bailey, Scott M.","Baumann, William T."]},{"key":"dc:contributor.department","label":"Department","values":["Electrical and Computer Engineering"]},{"key":"dc:creator","label":"Author","values":["Dhar, Saurav"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2013-10-30T08:00:19Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2013-10-30T08:00:19Z"]},{"key":"dc:date.issued","label":"Date","values":["2013-10-29"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Tech"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Electrical Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Virginia Polytechnic Institute and State University"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Ion source","Ionosphere","vacuum chamber","Low Earth Orbit"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:rights","label":"Dc Rights","values":["In Copyright"]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://rightsstatements.org/vocab/InC/1.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["vt_gsexam:1742"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10919/23931"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Understanding and improving ionospheric models is important for both military and civilian purposes. This understanding improves prediction of radio propagation used for communication and GPS navigation. Various space-borne instruments, such as retarding potential analyzers (RPAs) and ion traps are routinely flown in low earth orbit (LEO) to provide data for seeding/improve ionospheric models. This thesis describes and characterizes a new ion source that can be used to test and calibrate these space-borne instruments inside a laboratory vacuum chamber. Hot filaments are used to thermionically emit electrons inside the source. These electrons collisionally ionize neutral particles inside the source. Guided by ion-optics simulations, the ion and the electron trajectories inside the source are controlled to provide the required ion beams. A detailed description of the control electronics and the embedded controller for electron emission is discussed within. 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