The Laser Triggered Switch Program at Sandia National Laboratories is an intensive development study to understand and optimize the laser triggered gas switch (LTGS) for the Z-Refurbishment (ZR) project. The laser triggered gas switch is the final command-triggered switch in the machine, and reliability and performance of the switch is crucial. A modified LTGS trigger section with optical viewing windows perpendicular to the laser propagation is used to analyze a laser induced plasma spark in SF6 gas in order to quantify parameters such as spark length and plasma temperature. The laser spark is created through a focusing lens by the fourth-harmonic (266nm) of a 5ns FWHM pulsed Nd:YAG laser with 30mJ maximum energy output. Several diagnostic methods are used to analyze the laser spark. Visible spark length measurements are made using a lens system mounted to a CCD camera at gas pressures ranging from sub-atmosphere to four atmospheres. Differing focal length lenses are compared to determine an optimal focal length for a given gas pressure and laser energy. The visible length of the laser induced plasma channel is used as an indicator of the ability of a spark to trigger a switch at a given gas pressure and charge voltage. As a rule of thumb, the visible spark length must be at least 30% of the electrode gap spacing to produce acceptable switch run-time and jitter. Schlieren imaging and electrical length measurements using a capacitive probe are also used to obtain laser induced spark lengths. Spectroscopy is used to estimate laser plasma temperature from which plasma resistivity is calculated.
","abstract_html":"<p>The Laser Triggered Switch Program at Sandia National Laboratories is an intensive development study to understand and optimize the laser triggered gas switch (LTGS) for the Z-Refurbishment (ZR) project. The laser triggered gas switch is the final command-triggered switch in the machine, and reliability and performance of the switch is crucial. A modified LTGS trigger section with optical viewing windows perpendicular to the laser propagation is used to analyze a laser induced plasma spark in SF6 gas in order to quantify parameters such as spark length and plasma temperature. The laser spark is created through a focusing lens by the fourth-harmonic (266nm) of a 5ns FWHM pulsed Nd:YAG laser with 30mJ maximum energy output. Several diagnostic methods are used to analyze the laser spark. Visible spark length measurements are made using a lens system mounted to a CCD camera at gas pressures ranging from sub-atmosphere to four atmospheres. Differing focal length lenses are compared to determine an optimal focal length for a given gas pressure and laser energy. The visible length of the laser induced plasma channel is used as an indicator of the ability of a spark to trigger a switch at a given gas pressure and charge voltage. As a rule of thumb, the visible spark length must be at least 30% of the electrode gap spacing to produce acceptable switch run-time and jitter. Schlieren imaging and electrical length measurements using a capacitive probe are also used to obtain laser induced spark lengths. Spectroscopy is used to estimate laser plasma temperature from which plasma resistivity is calculated.</p>","abstract_has_math":false,"creators":["Clark, Waylon"],"institution":null,"degree_name":"Optical Science and Engineering","degree_level":"Masters","degree_discipline":"Optical Science and Engineering","degree_department":null,"school":null,"contributors":["Gilmore, Mark","Savage, Mark","Lynn, Alan"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2007,"date_issued":"2007-07-10T07:00:00Z","date_published":"2007-07-10T07:00:00Z","updated_at":"2026-07-24T05:27:04Z","subjects":["Laser plasmas.","Other Engineering"],"languages":["English"],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://digitalrepository.unm.edu/ose_etds/53","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Gilmore, Mark","Savage, Mark","Lynn, Alan"]},{"key":"dc:creator","label":"Author","values":["Clark, Waylon"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"thesis:degree_discipline","label":"Discipline","values":["Optical Science and Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Masters","Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Optical Science and Engineering"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Laser plasmas.","Other Engineering"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["English"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://digitalrepository.unm.edu/ose_etds/53"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["The Laser Triggered Switch Program at Sandia National Laboratories is an intensive development study to understand and optimize the laser triggered gas switch (LTGS) for the Z-Refurbishment (ZR) project. The laser triggered gas switch is the final command-triggered switch in the machine, and reliability and performance of the switch is crucial. A modified LTGS trigger section with optical viewing windows perpendicular to the laser propagation is used to analyze a laser induced plasma spark in SF6 gas in order to quantify parameters such as spark length and plasma temperature. The laser spark is created through a focusing lens by the fourth-harmonic (266nm) of a 5ns FWHM pulsed Nd:YAG laser with 30mJ maximum energy output. Several diagnostic methods are used to analyze the laser spark. Visible spark length measurements are made using a lens system mounted to a CCD camera at gas pressures ranging from sub-atmosphere to four atmospheres. Differing focal length lenses are compared to determine an optimal focal length for a given gas pressure and laser energy. The visible length of the laser induced plasma channel is used as an indicator of the ability of a spark to trigger a switch at a given gas pressure and charge voltage. As a rule of thumb, the visible spark length must be at least 30% of the electrode gap spacing to produce acceptable switch run-time and jitter. Schlieren imaging and electrical length measurements using a capacitive probe are also used to obtain laser induced spark lengths. Spectroscopy is used to estimate laser plasma temperature from which plasma resistivity is calculated.
"]},{"key":"dc:title","label":"Title","values":["Analysis of a laser induced plasma in high pressure SF6 gas for high-voltage, high-current switching"]}]}],"canonical_facts":{"dc:contributor":["Gilmore, Mark","Savage, Mark","Lynn, Alan"],"dc:creator":["Clark, Waylon"],"dc:description.abstract":["The Laser Triggered Switch Program at Sandia National Laboratories is an intensive development study to understand and optimize the laser triggered gas switch (LTGS) for the Z-Refurbishment (ZR) project. The laser triggered gas switch is the final command-triggered switch in the machine, and reliability and performance of the switch is crucial. A modified LTGS trigger section with optical viewing windows perpendicular to the laser propagation is used to analyze a laser induced plasma spark in SF6 gas in order to quantify parameters such as spark length and plasma temperature. The laser spark is created through a focusing lens by the fourth-harmonic (266nm) of a 5ns FWHM pulsed Nd:YAG laser with 30mJ maximum energy output. Several diagnostic methods are used to analyze the laser spark. Visible spark length measurements are made using a lens system mounted to a CCD camera at gas pressures ranging from sub-atmosphere to four atmospheres. Differing focal length lenses are compared to determine an optimal focal length for a given gas pressure and laser energy. The visible length of the laser induced plasma channel is used as an indicator of the ability of a spark to trigger a switch at a given gas pressure and charge voltage. As a rule of thumb, the visible spark length must be at least 30% of the electrode gap spacing to produce acceptable switch run-time and jitter. Schlieren imaging and electrical length measurements using a capacitive probe are also used to obtain laser induced spark lengths. Spectroscopy is used to estimate laser plasma temperature from which plasma resistivity is calculated.
"],"dc:identifier":["https://digitalrepository.unm.edu/ose_etds/53"],"dc:language":["English"],"dc:subject":["Laser plasmas.","Other Engineering"],"dc:title":["Analysis of a laser induced plasma in high pressure SF6 gas for high-voltage, high-current switching"],"thesis:degree_discipline":["Optical Science and Engineering"],"thesis:degree_level":["Masters","Thesis"],"thesis:degree_name":["Optical Science and Engineering"]},"updated_at":"2026-07-24T05:27:04Z"}