Analysis of energetic particle driven modes and interchange modes in LHD plasma using the gyro-fluid code FAR3d

Analysis of energetic particle driven modes and interchange modes in LHD plasma using the gyro-fluid code FAR3d | 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 Analysis of energetic particle driven modes and interchange modes in LHD plasma using the gyro-fluid code FAR3d J. Varela, K. Nagaoka, S. Ohdachi, K. Y. Watanabe, Y. Takemura, and 24 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6718076/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 22 Nov, 2025 Read the published version in Journal of Fusion Energy → Version 1 posted 9 You are reading this latest preprint version Abstract Energetic particles (EP) generated by the neutral beam injectors (NBI) in Large Helical Device (LHD) destabilize Alfvén Eigenmodes (AE) and energetic particle modes (EPM), leading to a reduction of the device performance. In particular, AE/EPM induce EP losses before thermalization that causes a lower plasma heating efficiency and damages to plasma facing components. Pressure gradient driven modes (PGDM) as interchange and ballooning modes also hamper the capability of LHD to confine the thermal plasma, limiting the maximum thermal plasma β of the discharge. The present study summarizes AE/EPM and PGDM characterization and optimization analysis performed in LHD plasma using the gyro-fluid code FAR3d. The linear and saturation phase of AE/EPM and PGDM leading to the destabilization of MHD burst, energetic-ion-driven resistive interchange mode (EIC) burst, internal collapse and saw-tooth like events are discussed. Optimization trends with respect to the NBI operation regime, magnetic field configuration, thermal plasma properties, external actuators and multiple EP populations effects are explored, comparing experiment and simulation data. Improved operation scenarios are identified and confirmed in dedicated experiments thanks to the minimization or avoidance of AE/EPM and PGDM along the discharge. Stellarator LHD EIC MHD AE energetic particles Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 22 Nov, 2025 Read the published version in Journal of Fusion Energy → Version 1 posted Editorial decision: Revision requested 19 Oct, 2025 Reviews received at journal 17 Oct, 2025 Reviewers agreed at journal 27 Aug, 2025 Reviews received at journal 03 Jul, 2025 Reviewers agreed at journal 17 Jun, 2025 Reviewers invited by journal 30 May, 2025 Editor assigned by journal 22 May, 2025 Submission checks completed at journal 22 May, 2025 First submitted to journal 21 May, 2025 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-6718076","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":464118949,"identity":"63c07cbb-e99f-47a5-84b9-fbc850bf9016","order_by":0,"name":"J. 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