{"paper":{"title":"Comparative analysis of wavenumber response in phase contrast and spiral phase imaging systems for plasma diagnostics","license":"http://creativecommons.org/licenses/by/4.0/","headline":"","cross_cats":["physics.optics"],"primary_cat":"physics.plasm-ph","authors_text":"Haruki Kawaguchi, Hirokazu Kobayashi, Jigme Zangpo, Ryo Yasuhara","submitted_at":"2026-07-31T11:32:39Z","abstract_excerpt":"Phase contrast imaging (PCI) has been used for decades to study plasma density fluctuations, but its wavenumber response $k$ is constrained by the phase plate groove width and beam waist. Spiral phase contrast imaging (SPCI) with a spiral phase plate may offer broader sensitivity, even though its output signal is quadratic, because it has no constraint except at the central singularity, i.e., $k = 0$. In this work, we numerically compare the wavenumber response of both techniques using two distinct models: (i) static square phase objects with scale lengths $R$ ranging from 5 to 25 mm, and (ii)"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2607.29307","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":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2607.29307/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"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"}