J. Seeman With contributions from the Super-B Staff September 17, 2009

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1 Super-B Accelerator R&D J. Seeman With contributions from the Super-B Staff September 17, 2009

2 Outline Overview Super-B parameters Frascati DAFNE crab waist results Interaction region Lattice Polarization PEP-II reusable components Conclusions

3 e+e- Colliders s -1 ) Lum minosity (cm -2 Super Factories SuperB SUPERKEKB Linear colliders 35 BINP c-τ KEKB ILC PEP-II CLIC Factories BEPCII CESR DAΦNE LEP PEP DORIS2 LEP CESR -c VEPP2000 LEP LEP PETRA BEPC VEPP-4M PETRA VEPP-2M SPEAR ADONE DCI ADONE B-Factories Φ-FactoriesF t i Future Colliders cm c.m. Energy(GeV) 10 27

4 Super-B Project Super-B aims at the construction of a very high luminosity (1x cm -2 s 1 ) asymmetric e + e flavor factory with a possible location on or near the campuses of the University of Rome at Tor Vergata or the INFN Frascati National Lab. Aims: Very high luminosity (~10 36 ) Flexible parameter choices. High reliability. Longitudinally polarized beam (e-) at the IP (>80%). Ability to collide at the Charm threshold.

5 Super-B Accelerator Contributors (~Fall 2009) D. Alesini, M. E. Biagini, R. Boni, M. Boscolo, A. Clozza, T. Demma, A. Drago, M. Esposito, A. Gallo, S. Guiducci, V. Lollo, G. Mazzitelli, C. Milardi, L. Pellegrino, M. Preger, P. Raimondi, R. Ricci, C. Sanelli, G. Sensolini, i M. Serio, F. Sgamma, A. Stecchi, A. Stella, S. Tomassini, i C. Vaccarezza, M. Zobov (INFN/LNF, Italy) K. Bertsche, A. Brachmann, Y. Cai, A. Chao, A. DeLira, M. Donald, A. Fisher, D. Kharakh, A. Krasnykh, N. Li, D. MacFarlane, Y. Nosochkov, A. Novokhatski, M. Pivi, J. Seeman, M. Sullivan, U. Wienands, J. Weisend, W. Wittmer, G. Yocky (SLAC, US) A. Bogomiagkov, S.Karnaev, I. Koop, E. Levichev, S. Nikitin, I. Nikolaev, I. Okunev, P. Piminov, S. Siniatkin, D. Shatilov, V. Smaluk, P. Vobly (BINP, Russia) G. Bassi, A. Wolski (Cockroft Institute, UK) S. Bettoni (CERN, Switzerland) M. Baylac, J. Bonis, R. Chehab, J. DeConto, Gpmez, A. Jaremie, G. Lemeur, B. Mercier, F. Poirier, C. Prevost, C. Rimbault, Tourres, F. Touze, A. Variola (CNRS, France) A. Chance, O. Napoly (CEA Saclay, France) F. Bosi, E. Paoloni (Pisa University, Italy)

6 A New Idea Pantaleo Raimondi came up with a new scheme to attain high luminosity in a storage ring Change the collision so that only a small fraction of one bunch collides with the other bunch Large crossing angle Long bunch length Due to the large crossing angle the effective bunch length (the colliding part) is now very short so we can lower β y * by a factor of 50 The beams must have very low emittance like present day light sources The x size at the IP now sets the effective bunch length In addition, by crabbing the magnetic waist of the colliding beams we greatly reduce the tune plane resonances enabling greater tune shifts and better tune plane flexibility This increases the luminosity performance by another factor of 2-3

7 How to get 100 times more L ξ y I b n β y * E = Luminosity equation Vertical beam-beam parameter Bunch current (A) Number of bunches IP vertical beta (cm) Beam energy (GeV) n ξ EI y EI b β * y Present day B-factories PEP-II KEKB E(GeV) 9x3.1 8x3.5 I b 1x x1 n I (A) 1.7x x1.6 β y * (cm) ξ y L (x10 34 ) Answer: Increase I b Decrease β y * Increase ξ y Increase n

8 Crab Waist Scheme (Raimondi)

9 Beam distributions at the IP Crab sextupoles Without waist line is orthogonal OFF Crab-sextupoles to the axis of one bunch Crab sextupoles ON With Crab-sextupoles waist moves to the axis of E. other Paoloni beam All particles from both beams collide in the minimum β y region, with a net luminosity gain

10 Crossing Angle Test at DAFNE

11 Data averaged for a full day Lumino osity [10 28 cm -2 s -1 ] βy=9mm,, Pw_ angle=1.9 βy=25mm, Pw_angle=0.3

12 Super-B Parameter Options

13 SuperB Site Choices C ~1.4 4km Frascati National Laboratories Frascati National Laboratories Existing Infrastructure

14 Collider Hall Roman Villa SuperB LINAC SPARX SuperB footprint at Tor Vergata Storage rings length = 1800 m

15 Perspective view

16 Layout: PEP-II magnets reuse Dipoles L mag (m) PEP HER PEP LER Available SBF HER Needed SBF LER Quads SBF Total Needed 30 0 L mag (m) PEP HER/LER SBF Total Needed Sexts L mag (m) PEP HER PEP LER SBF HER SBF LER SBF Total Needed 51* All PEP-II magnets can be used, dimensions and fields are in range RF requirements are met by the present PEP-II RF system

17 PEP-II Magnets and RF Components

18 Arc Lattice Raimondi, Biagini, Wittmer, Wienands Arc cell: flexible solution is based on decreasing the natural emittance by increasing μ x /cell, and simultaneously adding weak dipoles in the cell drift spaces to decrease synchrotron radiation All cells have: μ x =0.75, μ y =0.25 about 30% fewer sextupoles Better DA since all sextupoles are at I in both planes (although x and y sextupoles are nested) Distances between magnets compatible with PEP-II hardware All quads-bends-sextupoles sextupoles in PEP-II range Arcs & FF

19 W. Wittmer

20 Lattice Layout (Two Rings) (Sept 2009) Y. Nosochkov

21 x-y resonance suppression D.Shatilov s (BINP), ICFA08 Workshop Much higher luminosity! Typical case (KEKB, DAΦNE): Crab Waist On: 1. low Piwinski angle Φ < 1 1. large Piwinski angle Φ >> 1 2. β y comparable with σ z 2. β y comparable with σ x /θ

22 Comparison of design and achieved beam emittances (*achieved) E (GeV) C (m) γ ε x (nm) γε x (μm) ε y (pm) γε y (nm) Spring ILC-DR Diamond* ATF* SLS* SuperB LER SuperB HER Emittance tuning techniques and algorithms have been tested in simulations and experiments on the ATF and on the other electron storage rings to achieve such small emittances (ex. CesrTA as an ILC-DR test facility has a well established one).

23 Polarization versus Energy of HER (Wienands)

24 RF Plan: Use PEP-II RF system and cavities (Novokhatski, Bertsche)

25 PEP-II RF Cavities match Super-B needs.

26 Super-B RF Parameters (Sept 2009)

27 Injector Layout 1) dipole α and γ. 50 Hz 2) dipole β and θ. DC dipoles 4) dipoles λ and δ.. Pulsed inverted 50 Hz e- DR GUN A B C D R α β γ SHB L GeV 5.7 GeV 0.1GeV 0.8 GeV 70 m. 60 m. 320 m. PS e+ DR θ > 7 GeV e+ 400 m. R. Boni

28 The IR design The interaction region design has to accommodate the machine needs as well as the detector requirements Final focus elements as close to the IP as possible As small a detector beam pipe as backgrounds allow As thin as possible detector beam pipe Adequate beam-stay-clear for the machine Low emittance beams helps here Synchrotron radiation backgrounds under control Adequate solid angle acceptance for the detector

29 Final focus magnets Up to now, factories have typically developed interaction regions with at least one shared quadrupole However, with the large crossing angle of the SuperB design this means at least one beam is far off axis in a shared magnet This magnet therefore strongly bends the off-axis beam which produces powerful SR fans and even emittance growth To avoid this, the SuperB design has developed a twin final focus doublet for both beams

30 R&D on SC Quadrupoles at the IP Total field in black Coils array E. Paoloni (Pisa), S. Bettoni (CERN) Most recent design with BSC envelopes

31 SC Quadrupoles at the IP (E. Paoloni, S. Bettoni)

32 Inside the detector M. Sullivan 200 old support tube solenoids 300 mrad solenoids BaBar forward door 100 QD0 QD0 mm HER LER 0 QF1 QF1-100 PM QD0 200 mrad meters M. Sullivan Feb.13, 2009 SB_IT_ILC_P4_SR_3M

33 Photons/beam bunch M. Sullivan HER 2.9e7 2.5e6 LER 6.9e5 9.9e e5

34 TDR Topic List Injection System Polarized gun damping rings spin manipulators linac positron converter beam transfer systems Collider design Two rings lattice Polarization insertion IR design beam stay clear ultra-low 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 RF System RF specifications RF feedbacks Low level RF Synchronization and timing Site Civil construction Infrastructures & buildings Power plants Fluids plants Radiation safety Magnets Design of missing magnets Refurbishing existing magnets Field measurements QD0 construction Power supplies Injection kickers k Mechanical layout and alignment Injector supports Vacuum system Arcs pipe Straights pipe IR pipe e-cloud remediation i electrodes bellows impedance budget simulations pumping system Diagnostics Beam position monitors Luminosity monitor Current monitors Synchrotron light monitor R&D on diagnostics for low emittance Feedbacks Transverse Longitudinal Orbit Luminosity i Electronics & software Control system Architecture Design Peripherals

35 Conclusions Crossing angle collisions work well experimentally at DAFNE. Parameters for a high luminosity collider seem to hold together. Both Super-B and Super-KEKB now have similar parameters. Detailed site work and lattice layout computations are advancing. IR design is coming together Working on accelerator tolerances now. Aiming at a White Paper at end of 2009 and TDR at end of 2010.