{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"2d4cb76e91740bb974e5b1d72a47c65d9f73ac15a2bb705302c70a458ee5f187","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["a03e62e75accda137cc90bc41f4686acb1a2e183d62fcee7239e067efc45ffbc","ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b"],"salt":"d43ca5924af37fac2a5eca873da582d44b3e66c5ed77fa62a869982ed7d50c27","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"value","assisted_by":[],"external_id":"plasma.qed-cascades.intensity-limit","kind":"well-posed","literature_status":"contested","n":"2","parents":[],"plain":"If a few seed electrons start an avalanche, the resulting pair plasma could absorb the laser before it reaches full focus. The question is whether this sets a hard ceiling on how intense a focused laser can get.","posed_since":"2010","precise":"Fedotov, Narozhny, Mourou and Korn (2010) argued that cascades seeded by a single pair deplete the laser field and limit the attainable focused field to far below $E_{S} \\sim 4.4 \\times 10^{13}\\ \\mathrm{statvolt/cm}$. Determine the maximal attainable peak field in a vacuum focus as a function of input power ($10\\text{-}100\\ \\mathrm{PW}$, multi-beam dipole focusing), including seeding by residual gas, by target debris and by pairs created from vacuum, and decide whether ultrahigh vacuum, pulse shaping or tight focusing lifts the limit.","problem_ref":"a03e62e75accda137cc90bc41f4686acb1a2e183d62fcee7239e067efc45ffbc","references":"","settled_by":"3D QED particle-in-cell simulations with realistic seeding and pulse shapes giving the saturated peak field, tested by measuring focal intensity or gamma-ray yield at increasing power.","status_note":"","title":"Does pair cascade absorption cap the attainable laser intensity?","topic_ref":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"a25dab5d9e262d91d25d246f6094da8973d5bf4f1167e4d554310e9272811091","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"686be2801a9b8ccaa83a02e29e199fe888826fc3f9bb1987312519c3c94e5c79","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"jQeC4sAgJOdR60S3MtqYhk0Ruil_Pu9YaSFdqn1wzq-BZLekoeanBBBXs1CHo04b8R00A87jdsF3qtRIEVr7Cw"},"schema":"pubphys.envelope/1"},"record_hash":"a25dab5d9e262d91d25d246f6094da8973d5bf4f1167e4d554310e9272811091","leaf_index":3582}