{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"02da1155e6ab8a53849206e8e8029effd233a91401722cc8162a8a74ba005576","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b","d98cdaca290ac28b7ec854d5f47a9125d9fb4085c8bcc8ee300dc91c2ef4c18d"],"salt":"c108bbe39973b8f169897f45f4448c8c41ac1787c62b1a3cb83f21b888aa8800","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"yes-no","assisted_by":[],"external_id":"beams.csr-microbunching.ssmb-euv-source","kind":"well-posed","literature_status":"open","n":"2","parents":[],"plain":"If electrons in a storage ring stayed bunched into slices a few nanometers long on every turn, they would emit strong coherent ultraviolet light continuously; only the first step of this scheme has been shown.","posed_since":"2010","precise":"Steady-state microbunching (SSMB) uses laser modulators for longitudinal focusing in a low-momentum-compaction ring so that electrons stay in optical-scale microbunches turn after turn; retention of laser-induced microbunching at a $1.064 \\times 10^{-4}\\,\\mathrm{cm}$ wavelength over successive turns was reported at the Metrology Light Source, Berlin, in 2021 (Deng et al., https://doi.org/10.1038/s41586-021-03203-0). Determine whether a ring can hold microbunches of rms length below $\\sim 2 \\times 10^{-7}\\,\\mathrm{cm}$ in steady state, with quantum excitation, intrabeam scattering and laser phase noise included, giving coherent radiation at $1.35 \\times 10^{-6}\\,\\mathrm{cm}$ ($13.5\\,\\mathrm{nm}$) with average power near $10^{10}\\,\\mathrm{erg}/\\mathrm{s}$.","problem_ref":"d98cdaca290ac28b7ec854d5f47a9125d9fb4085c8bcc8ee300dc91c2ef4c18d","references":"","settled_by":"Measured steady-state coherent emission at the target wavelength whose power scales as the square of the number of electrons per microbunch.","status_note":"INSPIRE records through 2026 show proof-of-principle work at the Metrology Light Source and ring design studies, with no steady-state operation reported.","title":"Steady-state microbunching in a storage ring at EUV wavelengths","topic_ref":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"0a5f55d1bb5c4263eeb96a820dab29c326bc6bdbc5cdc966f42cef5fc02be5cb","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"2779d6766c9e5c338247e196eba7fa4d68a3ffa7eb474a6331e381b590f356c3","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"IzrVrKF_MGegmllfoURTY2a0RUpvZ9TAZqKjZiYaQV67U5GhX32Iscs3_3SQdpxPBXHOXtxC7INNQjrAalpgDg"},"schema":"pubphys.envelope/1"},"record_hash":"0a5f55d1bb5c4263eeb96a820dab29c326bc6bdbc5cdc966f42cef5fc02be5cb","leaf_index":2474}