Optical Characterization of a Non-Thermal Microwave Argon Plasma Column at Intermediate Pressure in the Presence of S8.

Optical Characterization of a Non-Thermal Microwave Argon Plasma Column at Intermediate Pressure in the Presence of S8. | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Optical Characterization of a Non-Thermal Microwave Argon Plasma Column at Intermediate Pressure in the Presence of S 8 . C. Moderie, A. Durocher-Jean, R. Martel, L. Stafford This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7088098/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Physicochemical mechanisms taking place in a non-thermal microwave argon-sulfur plasma column are studied by analyzing the effect of solid sulfur ( S8 ) on argon plasma properties at various injected power and pressure conditions. Direct optical imaging reveals an enhancement of the plasma radial contraction upon the addition of sulfur at low power, which contrasts with a transition from contacted to diffusive regime at high power. This phenomenon is further examined by optical emission spectroscopy to obtain the population of atomic sulfur (from actinometry on S atoms using Xe as the actinometer gas) and the neutral gas temperature (from the broadening of the 826, 840 and 842 nm argon emission lines). Depending on the operating conditions, the number density of atomic sulfur varies between 10 19 and 10 21 m −3 . As for the neutral gas temperature, it shows a significant rise upon the addition of sulfur. By correlating the population of S atoms with the corresponding thermal vaporization fluxes at the measured neutral gas temperature, it can be concluded that vaporization must involve other energy inputs linked to, for example, ion, electron and photon irradiations of S8. Further analyses of line intensity ratios along the plasma column reveal a decrease of the electron temperature associated with decreasing densities of atomic and dimer sulfur. Based on the obtained results, several mechanisms are discussed to explain the enhancement and annihilation of the plasma radial contraction in these conditions. Plasma column Optical plasma diagnostics Optical emission spectroscopy Actinometry Sulfur plasma Plasma sulfur chemistry Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7088098","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":486997287,"identity":"e19276d0-77bc-41e2-9420-04389027a722","order_by":0,"name":"C. Moderie","email":"","orcid":"","institution":"Université de Montréal","correspondingAuthor":false,"prefix":"","firstName":"C.","middleName":"","lastName":"Moderie","suffix":""},{"id":486997288,"identity":"6768a8bc-86a7-4e14-bb1e-9d23494eede2","order_by":1,"name":"A. Durocher-Jean","email":"","orcid":"","institution":"Université de Montréal","correspondingAuthor":false,"prefix":"","firstName":"A.","middleName":"","lastName":"Durocher-Jean","suffix":""},{"id":486997289,"identity":"30779c59-df6a-49f9-99ea-cb2564b07244","order_by":2,"name":"R. Martel","email":"","orcid":"","institution":"Université de Montréal","correspondingAuthor":false,"prefix":"","firstName":"R.","middleName":"","lastName":"Martel","suffix":""},{"id":486997290,"identity":"a1c4b8f4-f3bf-4370-ac58-1b82c704383e","order_by":3,"name":"L. Stafford","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA/ElEQVRIiWNgGAWjYBACPijNz97AwCDxAS5egFsLG5hMYJDsOcDAIDkDLmRApBZpHqK0SCQ/YPz5w06Ch7334W3btm1y5vK9Dx/8MGCQ52/ApSXNgJknIVmCh+e4sXVu221jyzZ2Y8MeAwbDGQdwaclhYGZIYK6zl0hjkwZqSdxwjI1NgscA6Fg8Whh/JNRL8IC0WEK0sP/8A9Qij0cLA0/CYYgWRqgtzCBbDHBp4XlmcJgn7TjQL8eYLXvO3TY2OJbGLC1jIGG4EYcWfvbkhw9/2FQDQ6yN8caPsttyBoePMX58U2EjL4dDCwhglZLArX4UjIJRMApGAUEAAO3RTGkBThIHAAAAAElFTkSuQmCC","orcid":"","institution":"Université de Montréal","correspondingAuthor":true,"prefix":"","firstName":"L.","middleName":"","lastName":"Stafford","suffix":""}],"badges":[],"createdAt":"2025-07-10 02:23:12","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7088098/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7088098/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":106237740,"identity":"5a6521c8-9749-4b71-96ab-ada07bb16422","added_by":"auto","created_at":"2026-04-06 14:12:36","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1061675,"visible":true,"origin":"","legend":"","description":"","filename":"PlasmaArSsubmitted.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7088098/v1_covered_3ecb7c6e-c87c-4c2c-8623-80a2f60d2389.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"\u003cp\u003eOptical Characterization of a Non-Thermal Microwave Argon Plasma Column at Intermediate Pressure in the Presence of S\u003csub\u003e8\u003c/sub\u003e.\u003c/p\u003e","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Plasma column, Optical plasma diagnostics, Optical emission spectroscopy, Actinometry, Sulfur plasma, Plasma sulfur chemistry","lastPublishedDoi":"10.21203/rs.3.rs-7088098/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7088098/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003ePhysicochemical mechanisms taking place in a non-thermal microwave argon-sulfur plasma column are studied by analyzing the effect of solid sulfur ( S8 ) on argon plasma properties at various injected power and pressure conditions. Direct optical imaging reveals an enhancement of the plasma radial contraction upon the addition of sulfur at low power, which contrasts with a transition from contacted to diffusive regime at high power. This phenomenon is further examined by optical emission spectroscopy to obtain the population of atomic sulfur (from actinometry on S atoms using Xe as the actinometer gas) and the neutral gas temperature (from the broadening of the 826, 840 and 842 nm argon emission lines). Depending on the operating conditions, the number density of atomic sulfur varies between 10\u003csup\u003e19\u003c/sup\u003e and 10\u003csup\u003e21\u003c/sup\u003e m\u003csup\u003e−3\u003c/sup\u003e. As for the neutral gas temperature, it shows a significant rise upon the addition of sulfur. By correlating the population of S atoms with the corresponding thermal vaporization fluxes at the measured neutral gas temperature, it can be concluded that vaporization must involve other energy inputs linked to, for example, ion, electron and photon irradiations of S8. Further analyses of line intensity ratios along the plasma column reveal a decrease of the electron temperature associated with decreasing densities of atomic and dimer sulfur. Based on the obtained results, several mechanisms are discussed to explain the enhancement and annihilation of the plasma radial contraction in these conditions.\u003c/p\u003e","manuscriptTitle":"Optical Characterization of a Non-Thermal Microwave Argon Plasma Column at Intermediate Pressure in the Presence of S8.","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-07-22 05:33:42","doi":"10.21203/rs.3.rs-7088098/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"c9ae0af1-6414-45bb-8c87-ade8bd535777","owner":[],"postedDate":"July 22nd, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-04-06T14:11:25+00:00","versionOfRecord":[],"versionCreatedAt":"2025-07-22 05:33:42","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7088098","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7088098","identity":"rs-7088098","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}