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Comprehensive overview and current status of the SuperB Accelerator project aiming for high luminosity at the University of Rome Tor Vergata campus. Details on design reports, workshops, meetings, and key contributors.
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SuperB AcceleratorOverview & Status M. E. Biagini, LNF-INFN for the SuperB Accelerator Team SuperB Meeting Elba, May 31th, 2008
SuperB Project • SuperB aims at the construction of a very high luminosity (1 to 4 x 1036 cm-2 s−1 ) asymmetric e+e− Flavour Factory, with possible location at the campus of the University of Rome Tor Vergata, near the INFN Frascati National Laboratory • A Conceptual Design Report was published in 2007 and reviewed by an International Review Committee, chaired by J. Dainton (UK). A report will be issued soon • A Mini-MAC, chaired by J. Dorfan (SLAC), will be set up before Summer to scrutinize the accelerator design • A Technical Design Report is planned to be ready by 2010 next effort will be to gather manpower and money
2th Joint Japan-US SuperB-Factory Workshop, Hawaii, US International SuperB Steering Committee established 4th SuperB Workshop, Villa Mondragone, Italy Accelerator test started at DAFNE, LNF, Italy International SuperB Study Group formed International Review Committee setup 5th SuperB Workshop in Paris, France 2th Accelerator retreat, SLAC, US CDR presented to INFN Management 2nd SuperB Workshop, LNF, Italy ICFA08 Workshop at BINP, Russia Detector R&D workshop, SLAC,US 3rd SuperB Workshop, SLAC, US 1st Accelerator retre, SLAC, US 1st SuperB Workshop, LNF, Italy CERN strategy group presentation Physics retreat at Valencia, Spain SuperB meeting, Daresbury,UK 2nd IRC meeting, Rome, Italy Machine Advisory Committee SuperB Meeting in Elba, Italy 1st IRC meeting, LNF, Italy CDR presented to ECFA CDR writing started CDR published 4 9 11 11 3 4 6 9 11 12 3 5 5 7 7 9 11 12 1 2 44 6 ? Month 2005 2006 2007 2008 The SuperB Process
“Conceptual Design Report” (450 pp), March 2007 INFN/AE-07/2,SLAC-R-856, LAL 07-15, arXiv:0709.0451 [hep-ex] www.pi.infn.it/SuperB/?q=CDR The SuperB CDR • 320 CDR signatures • 85 Institutions • 239 Experimentalists 200 pages on Accelerator Participants Countries
SuperB Accelerator CDR Contributors • M. E. Biagini, M. Boscolo, A. Drago, S. Guiducci, M. Preger, P. Raimondi, S. Tomassini, C. Vaccarezza, M. Zobov(INFN/LNF, Italy) • Y. Cai, A. Fisher, S. Heifets, A. Novokhatski, M.T. Pivi, J. Seeman, M. Sullivan, U. Wienands(SLAC, US) • T. Agoh, K. Ohmi, Y. Ohnishi(KEK, Japan) • I. Koop, S. Nikitin, E. Levichev, P. Piminov, D. Shatilov(BINP, Russia) • Wolski(Liverpool University, UK) • M. Venturini(LBNL, US) • S. Bettoni(CERN, Switzerland) • A. Variola(LAL/Orsay, France) • E. Paoloni, G. Marchiori(Pisa University, Italy)
Two approaches to achieve high luminosity • To increase Luminosity of ~ two orders of magnitude bordeline parameters are needed, such as (KEKB): • Very high currents • Smaller damping times Difficult and costly • Shorter bunches (avoidhourglass) operation (HOM, R F • Crab cavities for head-on collision power, backgrounds) • Higher power • SuperBexploits an alternative approach, with a new IP scheme (P.Raimondi, LNF): • Small beams (ILC-DR like) Tough to achieve • Large Piwinski angle and “crab waist” transformation • Currents comparable to present Factories Both require status-of-the-art technology
Ultra-low emittance (ILC-DR like) Very small b*at IP Large crossing angle “Crab Waist” scheme Small collision area Lower b ispossible NO parasitic crossings NO synchro-betatron resonances due to crossing angle SuperB approach Test at DAFNE now !!!
Beams distribution at IP Courtesy of E. Paoloni Crab sextupoles OFF waist line is orthogonal to the axis of one bunch Crab sextupoles ON waist moves to the axis of other beam All particles from both beams collide in the minimum by region, with a net luminosity gain
Crab-waist Studies at DANE, Frascati • DAFNE upgrade with improved Interaction Region to focus tighter the beams at IP and have a “large” crossing angle large Piwinski angle regime • Features: • Smaller collision area • Lower by* • No parasitic crossings • No synchro-betatron resonances due to the crossing angle • “Crab Waist” sextupoles • Results very encouraging so far with improved tunes shifts and higher luminosity with smaller currents P. Raimondi, next talk
Beam-beam tune scans for different collision schemes y=0.07 y=0.07 D. Shatilov (BINP) Case study: simulations for same beam parameters Blue: bad Red: good Black: very bad Head-on, Lmax = 2.45·1034 Ordinary crossing, Lmax = 2.05·1034 y=0.17 SuperB Large , CW = 0, Lmax = 1.6·1035 Crab Waist, Lmax = 1.05·1036
A. Novokhatski, SLAC CDR parameters New parameters RF power estimate Including synchrotron radiation, HOMs and RF power with 50% klystron efficiency
Lattice overview • The SuperB lattice as described in the CDR is the result of an international collaboration between experts from BINP, Cockcroft Institute, INFN, KEKB, LAL/Orsay, SLAC • Simulations were performed in many labs and with different codes: • LNF, BINP, KEK, LAL, CERN • The design is flexible but challenging and the synergy with the ILC Damping Rings which helped in focusing key issues, will be important for addressing some of the topics • Further studies after the CDR completion led to an evolution of the lattice to fit the Tor Vergata Site and to include polarization manipulation hardware.
The Rings • HER, 7 GeV and LER, 4 GeV, same length and similar lattice • Horizontal crossing angle at the IP and “crab waist” are used to maximize luminosity and minimize beam size blow-up • Ultra low emittance lattice: inspired by ILC Damping Rings • Circumference fits in the Tor Vergata campus site • No “emittance”wigglers used in Phase 1 • Beam currents below 2 A for a luminosity up to 2x1036 cm-2s-1 • Design based on recycling all PEP-II hardware: dipoles, quadrupoles, sextupoles, RF system, and possibly vacuum system (saving a lot of money) • Longitudinal polarization for e- is included • Maximized luminosity while keeping low wall power: • Total rings power: 17 MW, lower than PEP-II
IP layout, “Siamese twins QD0” M.Sullivan’s talk tomorrow • QD0 is common to HER and LER, with axis displaced toward incoming beams to reduce synchrotron radiation fan on SVT • Dipolar component due to off-axis QD0 induces, as in all crossing angle geometries, an over-bending of low energy out coming particles eventually hitting the pipe or detector • New QD0 design based on SC “helical-type” windings S. Bettoni (CERN), E. Paoloni (Pisa), S. Bettoni’s talk tomorrow
Total length 1800 m 20 m 280 m Lattice layout, PEP-II magnets reuse Dipoles Available Needed Quads Sexts All PEP-II magnets are used, dimensions and fields are in range RF requirements are met by the present PEP-II RF system
Polarization • Polarization of one beam is included in SuperB • Either energy beam could be the polarized one • The LER would be less expensive, the HER easier • Longitudinal polarization times and short beam lifetimes indicate a need to inject vertically polarized electrons • There are several possible IP spin rotators: • Solenoidslook better at present (vertical bends giving unwanted vertical emittance growth) • Many solutions proposed: Wienands (SLAC), Koop, Nikitin (BINP) • Final decision on which scheme is still to be taken, will depend on several factors (cost, feasibility, impact on operation, impact on luminosity performances, possibility to measure polarization) • Polarization section implementation in lattice is in progress for 2 solutions.
Spin Rotator Summary Note: Quads not enumerated No optics matching considered • Comments • Dipole rotator has v-bends => emittance? • Solenoid rotator has plane twister => tuning, emittance? • ??? 7 Snakes require √(7*2) ≈ 4 times tuning effort ??? U. Wienands, “Polarization” talk, this morning
The power of Continuous Injection Mode The best day > 1.2 /fb Essential !!! 1034 K. Oide, KEKB Roadmap
e+ DR e+ 4 GeV e- 7 GeV Injector Layout Room-temperature Linac less expensive, based on the LNF/SLAC know-how S-band ….. 2856 MHz same frequency of DAFNE-Linac, SPARC, SPARX project. Average accelerating gradient 23 MV/m medium-level E-field R. Boni’s talk, this morning SuperB Meeting, Isola d’Elba, May 31st – June 3rd, 2008
S. Tomassini’s talk, Monday SuperB LINAC SPARX 1st stage SPARX future 500 m 600 m SuperB footprint on Tor Vergata site
Injection System • Polarized gun • damping rings • spin manipulators • linac • positron converter • beam transfer systems • etc... • Collider design • Two rings lattice • Polarization insertion • IR design • beam stay clear • ultra-low emittance tuning • detector solenoid compensation • coupling correction • orbit correction • stability • beam-beam simulations • beam dynamics and instabilities • single beam effects • operation issues • injection scheme • etc… • RF system • RF specifications • RF feedbacks • Low level RF • Synchronization and timing • etc… TDR to do list(preliminary) • Vacuum system • Arcs pipe • Straights pipe • IR pipe • e-cloud remediation electrodes • bellows • impedance budget simulations • pumping system • etc… • Diagnostics • Beam position monitors • Luminosity monitor • Current monitors • Synchrotron light monitor • R&D on diagnostics for low emittance • etc… • Feedbacks • Transverse • Longitudinal • Orbit • Luminosity • Electronics & software • etc… • Control system • Architecture • Design • Peripherals • etc… • Site • Civil construction • Infrastructures & buildings • Power plants • Fluids plants • Radiation safety • etc… • Magnets • Design of missing magnets • Refurbishing existing magnets • Field measurements • QD0 construction • Power supplies • Injection kickers • Etc… • Mechanical layout and alignment • Injector • Rings • etc… Many topics already addressed in the CDR
Conclusions (1) • SuperB is a new machine which can exploit novel very promising design approaches: • large Piwinski anglewill allow for peak luminosity³ 1036 cm-2 s-1well beyond the current state-of-the-art, without a significant increase in beam currents or shorter bunch lengths • “crab waist”sextupoles used for suppression of dangerous resonances • low current design presents reduced detector and background problems, and affordable operating costs • polarized electron beam can produce polarized t leptons, opening an entirely new realm of exploration in lepton flavor physics • SuperBstudies are already proving useful to the accelerators and particle physics community • The principle of operation is under test atDANE
Conclusions (2) • SuperB has very ambitious goals in terms of peak and integrated luminosity, supported by a new collision scheme and confirmed by beam-beam simulations • The initial SuperB design meets the goals requested by the experimenters • The baseline lattice, based on the reuse of all PEP-II hardware, fits in the Tor Vergata University campus site, near Frascati • Spin rotator matching into HER lattice is in progress • Beam dynamics issues are receiving a fresh look • A CDR was issued in 2007 and has been reviewed by an International Review Committee, chaired by J. Dainton (UK) • The next phase for the accelerator group is to form a team to complete the Technical Design Report