{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"217c8b759f3f75ff29d38d4449032c25f7f2fba59bd6904970954eef1271bd8a","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":["ai:gpt-5.5"],"kind":"seed"},"parents":["c1b1c641085393db0156fb15d5b864dc904d5993b88860599d72675eb327487a","ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b"],"salt":"e2a67dd9f3da840197015a0f0926eaf2e50e054c6bc4b6c8e61774b7ae392f31","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"value","assisted_by":["ai:gpt-5.5"],"external_id":"plasma.reconnection.plasmoid-regime-3d","kind":"well-posed","literature_status":"partially-resolved","n":"2","parents":[],"plain":"In very large, highly conducting plasmas the reconnecting layer breaks into a chain of magnetic bubbles called plasmoids, which speeds reconnection up. In two-dimensional simulations the resulting rate is known, but real systems are three-dimensional, where the bubbles become twisted tubes and turbulence develops.","posed_since":"","precise":"In resistive (and Hall) MHD reconnection with Lundquist number $S = L v_{A}/\\eta$ far above the critical $S_{c} \\sim 10^{4}$, $2\\mathrm{D}$ simulations give a rate $\\sim 0.01 v_{A} B_{0}/c$ independent of $S$ and a power-law plasmoid size distribution. Determine in $3\\mathrm{D}$ the asymptotic rate as $S$ goes to $\\infty$, the critical $S_c$, the flux-rope size distribution and whether self-generated turbulence makes the $3\\mathrm{D}$ rate differ from the 2D value. An answer is converged $3\\mathrm{D}$ values with error bars.","problem_ref":"c1b1c641085393db0156fb15d5b864dc904d5993b88860599d72675eb327487a","references":"","settled_by":"3D MHD simulations converged in S and resolution, cross-checked against a high-S laboratory experiment.","status_note":"The 2D plasmoid-mediated rate of about 0.01 was established around 2009-2012; the 3D asymptotic regime is still under study in 2025-2026.","title":"Reconnection rate at very high Lundquist number in three dimensions","topic_ref":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"eb0c35c7ee189817f6ae94960c175d3b0c095233c5dbfc134f6d7f3c72b65c26","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"9c64647c4bcf252ee2f18875146bfbf53763fb3ab05fff9211790fb186d06254","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"DWjh4y1zQfoSVhcVnPA-vzRYEL1mNBzBhqRju77IRE6QUCKjDp4V-NIVLSZaEwdAwn_6a97G5R41hSLrTpbCAQ"},"schema":"pubphys.envelope/1"},"record_hash":"eb0c35c7ee189817f6ae94960c175d3b0c095233c5dbfc134f6d7f3c72b65c26","leaf_index":3596}