July 24, 2008Super-B Mini-MAC MeetingPage 1 Super-B Overview John Seeman Accelerator Systems Division SLAC.
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July 24, 2008Super-B Mini-MAC MeetingPage 1 Super-B Overview John Seeman Accelerator Systems Division SLAC
July 24, 2008Super-B Mini-MAC MeetingPage 2 Super-B Outline *Goals for the accelerator *Super-B layout *Super-B parameters *Luminosity options *Subsystems
July 24, 2008Super-B Mini-MAC MeetingPage 3 *Super-B aims at the construction of a very high luminosity (1 x 10 36 cm -2 s −1 ) asymmetric e + e − flavor factory, with possible location at the campus of the University of Rome Tor Vergata, near the INFN Frascati National Laboratory. *Aims: –Very high luminosity Desire 10 36 : experimenters say 10 35 will not get to the physics soon enough. –High reliability The goal is integrated luminosity! –Polarized e- at IP This is a relatively new addition by the users. –Ability to collide at Y4S and lower energy (~J/Psi) For maximum number of experimenters. Super-B Goals
July 24, 2008Super-B Mini-MAC MeetingPage 4 Super-B Accelerator Contributors *D. Alesini, M. E. Biagini, R. Boni, M. Boscolo, T. Demma, A. Drago, S. Guiducci, M. Preger, P. Raimondi, S. Tomassini, C. Vaccarezza, M. Zobov (INFN/LNF, Italy) *K. Bertsche, Y. Cai, A. Fisher, S. Heifets, A. Novokhatski, M.T. Pivi, J. Seeman, M. Sullivan, U. Wienands, W. Wittmer (SLAC, US) *T. Agoh, K. Ohmi, Y. Ohnishi (KEK, Japan) *I. Koop, S. Nikitin, E. Levichev, P. Piminov, D. Shatilov (BINP, Russia) *A. Wolski (Liverpool University, UK) *M. Venturini (LBNL, US) *S. Bettoni, D. Schulte (CERN, Switzerland) *A. Variola (LAL/Orsay, France) *E. Paoloni, G. Marchiori (Pisa University, Italy)
July 24, 2008Super-B Mini-MAC MeetingPage 5 2005200620072008 2 th Joint Japan-US SuperB-Factory Workshop, Hawaii, US International SuperB Study Group formed 1 st SuperB Workshop, LNF, Italy International SuperB Steering Committee established 2 nd SuperB Workshop, LNF, Italy 3 rd SuperB Workshop, SLAC, US 1 st Accelerator retreat, SLAC, US 4 th SuperB Workshop, Villa Mondragone, Italy SuperB meeting, Daresbury,UK CDR writing started CDR published 5 th SuperB Workshop in Paris, France CDR presented to INFN Management CDR presented to ECFA International Review Committee setup 2 th Accelerator retreat, SLAC, US 1 st IRC meeting, LNF, Italy 2nd IRC meeting, Rome, Italy Accelerator test started at DA NE, LNF, Italy Physics retreat at Valencia, Spain Detector R&D workshop, SLAC,US ICFA08 Workshop at BINP, Russia SuperB Meeting in Elba, Italy Mini MAC, EPAC08, Italy 4 9 113 4 6 9 11 1235 5 7 7 9 11 121 2 3 4 4 6 6.. The Super-B Process Month CERN strategy group presentation (M. Biagini) 2 nd Meeting with ECFA
July 24, 2008Super-B Mini-MAC MeetingPage 6 Super-B CDR Spring 2007 Initial Super-B design with the ILC damping ring parameters. These parameters are still valid. However, the parameters have evolved since the CDR to minimize power, shorten the tunnel, and and add polarization.
July 24, 2008Super-B Mini-MAC MeetingPage 7 SuperB footprint on Tor Vergata site SuperB Ring (about 1800m) SPARX Roman Villa 100m SuperB Injector (about 400m) SuperB Main Building
July 24, 2008Super-B Mini-MAC MeetingPage 8 What about SPAR-X FEL? *
July 24, 2008Super-B Mini-MAC MeetingPage 9 Super-B builds on the Successes of Past Accelerators *PEP-II LER stored beam current (3.2 A in 1722 bunches (4 nsec) at 3.1 GeV at 23 nm with little ECI effect on luminosity. *Low emittance lattices designed for ILC damping rings, PETRA-3, NSLC-II, and PEP-X. (few nm horizontal x few pm vertical) *Very low emittance achieved in an ILC test ring: ATF. *Successful crab-waist luminosity improvement at DAFNE in Frascati. *Successful crab-cavity tests at KEKB at low currents. *Spin manipulation tests in Novosibirsk. *Efficient spin generation with a high current gun and spin transport to the final focus at the SLC. *Successful two beam interaction region built by KEKB and PEP-II. *Continuous injection works with the detector taking data (KEKB and PEP-II)
July 24, 2008Super-B Mini-MAC MeetingPage 10 *Two options: *High currents –Very high currents –Smaller damping time High power components –Shorter bunches Costly to operate –Crab cavities for head-on collision –Higher power *SuperB exploits an alternative approach, with a new IP scheme: –Small emittance beams (ILC-DR like) –Large Piwinski angle and “crab waist” –Currents comparable or smaller than present Factories Basic concepts A lot of fine tuning!
July 24, 2008Super-B Mini-MAC MeetingPage 11 SuperB Parameters (Biagini) Add to these parameters head room factors: X 2 in beam current X 2 in number of bunches Injection rate for higher losses IP beta ranges
July 24, 2008Super-B Mini-MAC MeetingPage 12 Super-B transparency condition *To have equal tune shifts with asymmetric energies in PEP-II and KEKB the “design” beam currents ratio is: I + /I - ~ E - /E + *Due to SuperB large crossing angle, new conditions are possible: LER and HER beams can have different emittances and * and equal currents Option 1 for Super-B Option 2 for SuperB
July 24, 2008Super-B Mini-MAC MeetingPage 18 Beams distribution at IP Crab sextupoles OFF Crab sextupoles ON waist line is orthogonal to the axis of one bunch waist moves to the axis of other beam All particles from both beams collide in the minimum y region, with a net luminosity gain E. Paoloni
July 24, 2008Super-B Mini-MAC MeetingPage 19 Crab-waist Studies at DAFNE at INFN Frascati *P. Raimondi et al: DAFNE upgrade with improved interaction region to focus tighter the beams at IP and have a “large” crossing angle large Piwinski angle *Features: –Smaller collision area –Lower y –No parasitic crossings –No synchro-betatron resonances due to the crossing angle –“Crab Waist” sextupoles *Results successful and very encouraging so far with improved tunes shifts and higher luminosity with smaller currents.
July 24, 2008Super-B Mini-MAC MeetingPage 21 Lattice *The SuperB lattice as described in the Conceptual Design Report 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 *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. M. Biagini
July 24, 2008Super-B Mini-MAC MeetingPage 22 LER HER Cell #2 Cell #1 Cell #2 Arc cells layout M. Biagini
July 24, 2008Super-B Mini-MAC MeetingPage 23 Interaction Region Similar to ILC IR *
July 24, 2008Super-B Mini-MAC MeetingPage 24 Lattice layout, PEP-II magnets reuse Total length 1800 m 280 m 20 m L mag (m)0.455.4 PEP HER-194 PEP LER194- SBF HER-130 SBF LER22418 SBF Total224148 Needed300 Dipoles L mag (m)0.560.730.430.70.4 PEP HER20282--- PEP LER--353-- SBF HER165108-22 SBF LER8810816522 SBF Total25321616544 Needed51*134044 Quads Available Needed All PEP-II magnets are reused. Dimensions and fields are properly sized. L mag (m)0.250.5 PEP HER/LER188- SBF Total3724 Needed1844 Sexts
July 24, 2008Super-B Mini-MAC MeetingPage 25 PEP-II RF Cavities Early design and testing at LBL. High power production cells. Fully fitted cavity units with HOM dampers.
July 24, 2008Super-B Mini-MAC MeetingPage 28 Injection * Needed rate: 1.85 A = 3E13 particles Lifetime = 15 minute Injector = 5E9 at 100 Hz. R. Boni
July 24, 2008Super-B Mini-MAC MeetingPage 29 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 –HER was chosen. *Longitudinal polarization times and short beam lifetimes indicate a need to inject vertically polarized electrons. –The plan is to use a polarized e- source similar to the SLAC SLC source. *There are several possible IP spin rotators: –Solenoids look better at present (vertical bends give unwanted vertical emittance growth) *Expected longitudinal polarization at the IP of about 87%(inj) x 97%(ring)=85%(effective) *Polarization section implementation in lattice: in progress with initial success U. Wienands
July 24, 2008Super-B Mini-MAC MeetingPage 30 HER spin manipulation hardware Spin rotators in the HERFull HER lattice Wittmer, Wienands, Biagini
July 24, 2008Super-B Mini-MAC MeetingPage 31 Conclusions *The SuperB design meets the goals requested by the experimenters. *IR polarization rotators have now been added to the lattice. *The next phase for the accelerator group is to form a team to work on a Technical Design Report including engineering. *A Change Control Board for parameters is likely needed. *The areas for further concentration: –Low emittance generation, tuning, dynamic aperture –Crab waist issues –IR design (low betas) –Beam-beam interaction (layout) –Continuous injection with polarization and tolerances –Further beam dynamics studies with ECI for e+ and ions for e- –Vibration analysis.