{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"78c0b7f0bdadf64f071c91c639aad8df5e23102cc9ce9f3dd85fb1dd715ee414","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["3de8dad991414c538392d7daf5ca1ebf1c192ce235057d1d18d6c267127e4b5d","ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b"],"salt":"884bbc903e974dcbb974fc025df30637ebbdcfd06b465c39a394cd647017d2d7","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"yes-no","assisted_by":[],"external_id":"plasma.qed-cascades.lab-avalanche-threshold","kind":"well-posed","literature_status":"open","n":"2","parents":[],"plain":"In colliding laser beams of enough intensity, the field itself should keep re-accelerating new pairs so their number grows exponentially. No laboratory has yet reached the needed intensity or seen this growth.","posed_since":"2008","precise":"In counterpropagating or multi-beam (dipole-wave) laser fields an avalanche cascade, with pair number growing as $\\exp(\\Gamma t)$ over several laser periods, is predicted above an intensity of order $10^{31}\\ \\mathrm{erg}\\ \\mathrm{s}^{-1}\\ \\mathrm{cm}^{-2}$ for 1-micron light, about ten times the record peak intensity of about $10^{30}\\ \\mathrm{erg}\\ \\mathrm{s}^{-1}\\ \\mathrm{cm}^{-2}$ (2021, approximate). Determine the minimal laser energy and geometry (colliding pulses, dipole focusing, single-pulse reflection from a plasma mirror) at which the pair number grows by several e-foldings, and observe it through positron yield scaling that exceeds the one-generation shower prediction.","problem_ref":"3de8dad991414c538392d7daf5ca1ebf1c192ce235057d1d18d6c267127e4b5d","references":"","settled_by":"A positron-yield measurement versus intensity at a multi-10-PW facility showing exponential growth beyond seeded shower predictions.","status_note":"No laboratory avalanche cascade is known to this compilation as of 2026.","title":"First laboratory observation of a self-sustained avalanche QED cascade","topic_ref":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"56a71861f63b87dae4770044fb62725b4278a7f958283d3dae27f1aa11174177","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"71a5e99ea62c6e7ac18b896908faf4ed4a10a66ee7d42d1a8bf52338062c5fbb","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"sRxj6eIRiqTzyK4oiLhe-b0KlR4YwXF6veerHv9mdiQ3pPRbKW27QrtiE_-PoYPBVzcU0XEmS5OtyS7nCKZVCA"},"schema":"pubphys.envelope/1"},"record_hash":"56a71861f63b87dae4770044fb62725b4278a7f958283d3dae27f1aa11174177","leaf_index":3584}