Super-c-tau factory in Novosibirsk (WP7) E. Levichev Budker Institute of Nuclear Physics Novosibirsk, RUSSIA CREMLIN kick-off meeting, 6-7 October 2015 NRC Kurchatov Institute
Budker Institute Founded by G.Budker in 1958, ~3000 staff (scientists 500, engineers 400, lab technicians 400, workshop personnel 1000, administrative, support personnel). Main activities: HEP, colliders, accelerator science and technology, SR and FEL, thermonuclear researches. 2
Scientific case D-Dbar mixing CP violation searches in charm decays Rare and forbidden charm decays Standard Model tests in leptons decays Searches for lepton flavor violation mg CP/T violation searches in leptons decays Requirements: L > 10 34 cm -2 s -1, longitudinal polarization Production of the polarized anti-nucleons Energy = 1 GeV with reduced luminosity 3
Super c-tau requirements Beam energy from 1.0 GeV to 2.5 GeV Peak luminosity is 10 35 cm -2 s -1 at 2 GeV Electrons are polarized longitudinally at IP Energy calibration by Compton backscattering (~(5 10) 10-5 ) 4
Details Two rings with Crab Waist collision scheme and single interaction point Sub-mm y at IP Preserving of emittance and damping times through the whole energy range to optimize the luminosity 5 Siberian snakes to obtain the longitudinally polarized electrons for the whole energy range Highly effective positron source (50 Hz top-up injection) Polarized electron source 2.5 GeV full energy linac as injector 5
Main ring scheme 6
Facility scheme 7
Parameters Energy 1.0 GeV 1.5 GeV 2.0 GeV 2.5 GeV Circumference 780 m Emittance hor/ver 8 nm/0.04 nm @ 0.5% coupling Damping time hor/ver/long 30/30/15 ms Bunch length 16 mm 11 mm 10 mm 10 mm Energy spread 10.1 10-4 9.96 10-4 8.44 10-4 7.38 10-4 Momentum compaction 1.00 10-3 1.06 10-3 1.06 10-3 1.06 10-3 Synchrotron tune 0.007 0.010 0.009 0.008 RF frequency 508 MHz Harmonic number 1300 Particles in bunch 7 10 10 Number of bunches 390 (10% gap) Bunch current 4.4 ma Total beam current 1.7 A Beam-beam parameter 0.15 0.15 0.12 0.095 Luminosity 0.63 10 35 0.95 10 35 1.00 10 35 1.00 10 35 8
Polarization Degree Polarization of electron beam Electron beam polarization enrich the experimental program notably. We plan to provide the beam polarization in the whole energy range with the help of Siberian Snakes invented at BINP 1 0.8 5 snakes 0.6 3 snakes 0.4 0.2 1 snake 0 1 1.2 1.4 1.6 1.8 2 2.2 2.4 2.6 Beam Energy, GeV 9
Luminosity tune scan CW advantage: BB coupling resonances are suppressed Wide red area corresponds to 10 35 cm -2 s -1 10
Beam-Beam simulation Working BB parameter CW advantage: even for y = 0.2 there is no large beam blowup and luminosity degradation. Safety margin for BB effects. 11
Injection facility Image of the first positron beam in 2013 Linear accelerator 500 MeV damping ring Beam transfer line 12
Status Super c-tau factory is approved by Russian Ministry of Science and Education as one of the six mega-science projects. A physics case is considered in details. Conceptual design of the collider, detector and injection facility is completed. The following documentation is prepared: preliminary and conceptual design reports, road map, civil construction and engineering design report. ECFA officially approved Super c-tau factory in Novosibirsk. Super c-tau factory was endorsed by Europe Experts meeting in Brussels on 19 June 2013. MoUs have signed with CERN, KEK (Japan), INFN (Italy), JINR (Dubna), John Adams Institute (UK), etc. 13
Design documents I Preliminary Design Report 2010, 178 pp Conceptual Design Report 2011, 202 pp 14
Design documents II Road Map 2011, 112 pp Civil Construction Design, 2012, 12 volumes 15
International evaluation Robert Aymar, Colin Carlile, Helmut Dosch, Susanna Gota- Goldman, Jean Moulin, Steve Myers, Steve Sandner, Horst Stoecker, Ann Uustalu 16
Cooperation MoU signed with CERN, KEK (Japan), INFN (Italy), John Adams Institute (UK), JINR (Dubna), etc. The project was supported in person by Nobel Prize winners Martin Perl and David Gross, CERN DG Rolf Heuer, other prominent scientists. 17
CERN FCC-ee M. Benedikt 18
BINP contribution to FCC-ee BINP specialists first pointed out to the major luminosity limiting process at high energy beamstrahlung (Telnov, arxiv:1203.6563, 29 Mar 2012, Bogomyagkov /Levichev/Shatilov, Phys. Rev. AB 17, 28 Apr 2014). To increase the luminosity at low energy of FCC-ee (~40 GeV-100 GeV per beam), BINP experts have proposed a Crab Waist collision scheme that was adopted as a baseline in June 2015. A 100-km lattice of the FCC-ee collider was designed by the BINP team. MDI was considered and the scheme to correct a detector solenoidal field was proposed and studied. Different methods of energy calibration is under consideration. A short prototype of the double-aperture compact SC final focus quadrupole with 100 T/m gradient is under development. Etc. 19
CERN contribution to SCT Full size FF quadrupole prototype. Prototype of the IP area with FF doublet, solenoids and atni-solenoids, correction coils, etc. Powerful CERN computer cluster is used by BINP specialists to simulate beam-beam effects, lattice design, nonlinear beam dynamics study, etc. Precise luminosity monitor is under development at CERN (can be used at SCT also) Injector of polarized e- beam. Etc. 20
Synergy of FCC-ee and STC Extremely low beta-y at IP (~1 mm). Both projects needs similar technical solutions to reach it. Extremely large peak luminosity (~10 35-10 36 cm -2 s -1 ). Show-stoppers for luminosity increase should be revealed. High IR chromaticity required strong sextupoles which reduce dynamic aperture and momentum acceptance. Advanced schemes to improve DA and MA are needed for both projects. (SR sources, ion colliders) *) Low emittance (especially vertical). Factors increasing the vertical emittance should be studied. (SR sources) Complicated FF arrangement. Magnets simulation, development and prototyping is necessary. (SR sources, ion colliders) Etc., etc., etc. *) Solutions which will be obtained can be useful for other mega-science projects 21
Conclusion Electron-positron collider Super c-tau factory with unprecedented luminosity was proposed and studied at BINP. SCT preparation stage is completed and we are ready to start technical design and construction. Design study of the future e+e- collider FCC-ee is started at CERN. To reach high performance FCC-ee and SCT apply similar concepts (CW, polarization, etc.) which gives us a solid basis for mutually fruitful and beneficial collaboration between CERN and BINP in the frame of CREMLIN WP7. 22