{"paper":{"title":"Measurement of a 2D fast-ion velocity distribution function by tomographic inversion of fast-ion D-alpha spectra","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"physics.plasm-ph","authors_text":"Asger Schou Jacobsen, Benedikt Geiger, Bill Heidbrink, Dmitry Moseev, Frank Leipold, Giovanni Tardini, Jens Madsen, Jesper Rasmussen, Manuel Garc{\\i}a-Munoz, Markus Weiland, Mirko Salewski, Morten Stejner, Soren Bang Korsholm, Stefan Kragh Nielsen, the ASDEX Upgrade Team","submitted_at":"2015-09-28T20:16:12Z","abstract_excerpt":"We present the first measurement of a local fast-ion 2D velocity distribution function $f(v_\\parallel, v_\\perp)$. To this end, we heated a plasma in ASDEX Upgrade by neutral beam injection and measured spectra of fast-ion D-alpha (FIDA) light from the plasma center in three views simultaneously. The measured spectra agree very well with synthetic spectra calculated from a TRANSP/NUBEAM simulation. Based on the measured FIDA spectra alone, we infer $f(v_\\parallel, v_\\perp)$ by tomographic inversion. Salient features of our measurement of $f(v_\\parallel, v_\\perp)$ agree reasonably well with the "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1509.08482","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}