{"paper":{"title":"The beam energy measurement system for the Beijing electron-positron collider","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["hep-ex"],"primary_cat":"physics.acc-ph","authors_text":"A.A.Krasnov, A.A.Zhukov, A.G.Shamov, C.D.Fu, C.P.Shen, E.E.Pyata, E.V.Abakumova, F.A.Harris, G.S.Varner, H.M.Qu, H.Y.Dong, I.B.Nikolaev, J.Q.Xu, J.Y.Zhang, K.Yu.Todyshev, M.N.Achasov, N.Yu.Muchnoi, Q.Liu, Q.Qin, Q.Xiao, S.L.Olsen, T.B.Zhang, V.E.Blinov, V.V.Kaminsky, X.Cai, X.H.Mo, Y.F.Wang, Y.H.Zhang","submitted_at":"2011-09-27T04:39:03Z","abstract_excerpt":"The beam energy measurement system (BEMS) for the upgraded Beijing electron-positron collider BEPC-II is described. The system is based on measuring the energies of Compton back-scattered photons. The relative systematic uncertainty of the electron and positron beam energy determination is estimated as 2 \\cdot 10^{-5}. The relative uncertainty of the beam's energy spread is about 6 %."},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1109.5771","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}