{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"e2decabbeb4fbf55c43cafe7434371b9474281cacff059e615d1f9519ff77fba","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b","dea5b75dcdbb182ed7a0e7fd916ec327dd01d61c06f3a389f15cf952a3454e20"],"salt":"73a1d2a44133f44bec5478248ef766d222e9315685c91c393a561619205183f2","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"yes-no","assisted_by":[],"external_id":"beams.beam-cooling.muon-6d-final-cooling","kind":"well-posed","literature_status":"open","n":"2","parents":[],"plain":"Muons must be squeezed in phase space by a factor of about a million within microseconds, by passing them through absorbers and re-accelerating them; the full chain has never been built.","posed_since":"","precise":"Transverse ionization cooling of muons through a single absorber was demonstrated by MICE (published 2020). Determine whether a realistic 6D cooling channel plus final cooling stage can reach normalized transverse emittance of approximately $2.5 \\times 10^{-3}$ cm and longitudinal emittance of approximately $7\\,\\mathrm{cm}$ with overall muon transmission above $\\sim 10$ percent, including RF limits in solenoid fields, absorber heating, space charge and muon decay.","problem_ref":"dea5b75dcdbb182ed7a0e7fd916ec327dd01d61c06f3a389f15cf952a3454e20","references":"","settled_by":"An end-to-end simulation with engineering-feasible fields and gradients reaching both emittances, confirmed by a 6D cooling demonstrator for the first stages.","status_note":"","title":"Reaching muon collider target emittances by ionization cooling","topic_ref":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"d40db6fff848f4a4988d2356ecd9de742bb201f580d77809c897050f200ac326","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"3f1d3822f7e3ead0c642ba41eb16e655632f5a8fba9387a644886d845421f9ac","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"NvZkDlgNrMtbgnlT24G0IFWeO_7RDNXosV1Xh0vfBH7Xp_s_HRCi2X3sU-Op7TJ7WT0QMfaHMpGjUf_Tw_h9BQ"},"schema":"pubphys.envelope/1"},"record_hash":"d40db6fff848f4a4988d2356ecd9de742bb201f580d77809c897050f200ac326","leaf_index":2462}