SuperB Accelerator Overview & Status M. E. Biagini, LNF-INFN for the SuperB Accelerator Team SuperB Meeting Elba, May 31 th, 2008

SuperB aims at the construction of a very high luminosity (1 to 4 x 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 SuperB Project

The SuperB Process 2th Joint Japan-US SuperB-Factory Workshop, Hawaii, US International SuperB Study Group formed 1st SuperB Workshop, LNF, Italy International SuperB Steering Committee established 2nd SuperB Workshop, LNF, Italy 3rd SuperB Workshop, SLAC, US 1st Accelerator retre, SLAC, US 4th SuperB Workshop, Villa Mondragone, Italy SuperB meeting, Daresbury,UK CDR writing started CDR published 5th SuperB Workshop in Paris, France CDR presented to INFN Management CDR presented to ECFA International Review Committee setup 2th Accelerator retreat, SLAC, US 1st IRC meeting, LNF, Italy 2nd IRC meeting, Rome, Italy Accelerator test started at DAFNE, LNF, Italy Physics retreat at Valencia, Spain Detector R&D workshop, SLAC,US ICFA08 Workshop at BINP, Russia SuperB Meeting in Elba, Italy Machine Advisory Committee CERN strategy group presentation ? Month

The SuperB CDR 320 CDR signatures 85 Institutions 239 Experimentalists Countries Participants “Conceptual Design Report” (450 pp), March 2007 INFN/AE-07/2,SLAC-R-856, LAL 07-15, arXiv: [hep-ex] pages on Accelerator

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)

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 (avoid hourglass) operation (HOM, RF –Crab cavities for head-on collision power, backgrounds) –Higher power SuperB exploits 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 Two approaches to achieve high luminosity

Ultra-low emittance (ILC-DR like) Very small    at IP Large crossing angle “Crab Waist” scheme Small collision area Lower  is  possible NO parasitic crossings NO synchro-betatron resonances due to crossing angle SuperB approach Test at DA  NE now !!!

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 Courtesy of E. Paoloni

Crab-waist Studies at DA  NE, Frascati DA  NE 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  y * –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

SuperB Parameters

Comparison of SuperB to Super-KEKB ParameterUnitsSuperBSuper-KEKB EnergyGeV4x73.5x8 Luminosity10 36 /cm 2 /s1.0 to to 0.8 Beam currentsA1.9x1.99.4x4.1 y*y* mm x*x* cm3.5x Crossing angle (full)mrad to 0. RF power (AC line)MW17 to 2580 to 90 Tune shifts(x/y)0.0004/ /0.3

Beam-beam tune scans for different collision schemes Head-on, L max = 2.45·10 34 Ordinary crossing, L max = 2.05·10 34 Large , CW = 0, L max = 1.6·10 35 Crab Waist, L max = 1.05·10 36  y =0.17  y =0.07 Case study: simulations for same beam parameters Blue: bad Red: good Black: very bad SuperB D. Shatilov (BINP)

RF power estimate Including synchrotron radiation, HOMs and RF power with 50% klystron efficiency A. Novokhatski, SLAC CDR parameters New parameters

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 2x10 36 cm -2 s -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

S. Bettoni (CERN), E. Paoloni (Pisa), S. Bettoni’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 IP layout, “Siamese twins QD0” M.Sullivan’s talk tomorrow

Lattice layout, PEP-II magnets reuse Total length 1800 m 280 m 20 m Dipoles Quads Available Needed All PEP-II magnets are used, dimensions and fields are in range RF requirements are met by the present PEP-II RF system Sexts L mag (m) PEP HER/LER195- SBF Total3724 Needed L mag (m) PEP HER PEP LER SBF HER SBF LER SBF Total Needed L mag (m) PEP HER-194 PEP LER192- SBF HER-130 SBF LER22418 SBF Total Needed-320

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: –Solenoids look 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 Comments –Dipole rotator has v-bends => emittance? –Solenoid rotator has plane twister => tuning, emittance? –??? 7 Snakes require √(7*2) ≈ 4 times tuning effort ??? Note: Quads not enumerated No optics matching considered U. Wienands, “Polarization” talk, this morning

The best day > 1.2 /fb The power of Continuous Injection Mode K. Oide, KEKB Roadmap Essential !!!

Injector Layout Room-temperature Linac less expensive, based on the LNF/SLAC know-how S-band … MHz same frequency of DAFNE-Linac, SPARC, SPARX project. Average accelerating gradient 23 MV/m medium-level E-field SuperB Meeting, Isola d’Elba, May 31st – June 3rd, 2008 e+ 4 GeV e+ DR e- 7 GeV R. Boni’s talk, this morning

SPARX 1 st stage SuperB LINAC SPARX future SuperB footprint on Tor Vergata site 600 m 500 m S. Tomassini’s talk, Monday

TDR to do list (preliminary) 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… 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

SuperB is a new machine which can exploit novel very promising design approaches: – large Piwinski angle will allow for peak luminosity  cm -2 s -1 well 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  leptons, opening an entirely new realm of exploration in lepton flavor physics SuperB studies are already proving useful to the accelerators and particle physics community The principle of operation is under test at DA  NE Conclusions (1)

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