{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"9d3c148d06880354309552ab235cff4fefb1dd47144b247ab0e40d98fdfda7e3","created":"2026-10-03T07:18:08Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"fcb741356a3ec9a68e4a19cc00773b1d4f489b5f437e8a3ddf22f83010d5b47d","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":"1","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 $E_{S} \\sim 4.4e13\\ \\mathrm{statvolt/cm}$. 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":null,"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":"3d0d7926a3332ed1d5c98bce793a625e7064aa0a336ed90e374a074aaf4cfe04"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"a03e62e75accda137cc90bc41f4686acb1a2e183d62fcee7239e067efc45ffbc","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"bc296c5503eac53b4df544396acbb0eab7ea5304d9c10a692b7c6bf2e14c24f5","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"kXLU1qrbH_8CJLmCEU7jxbDDR-c40bwNxS8BmTV1l161NInq6HW44LuEKxIJtX2qSdBB-wS47CxnzCRzzqiyBw"},"schema":"pubphys.envelope/1"},"record_hash":"a03e62e75accda137cc90bc41f4686acb1a2e183d62fcee7239e067efc45ffbc","leaf_index":1851}