01 Circular Colliders

A02 Lepton Colliders

Paper Title Page
MOOCMH03 Beam Commissioning Status of Superconducting Crab Cavities in KEKB 42
 
  • Y. Yamamoto, K. Akai, K. Ebihara, T. Furuya, K. Hara, T. Honma, K. Hosoyama, A. Kabe, Y. Kojima, S. Mitsunobu, Y. Morita, H. Nakai, K. Nakanishi, M. Ono
    KEK, Ibaraki
  • T. Kanekiyo
    Hitachi Technologies and Services Co., Ltd., Kandatsu, Tsuchiura
 
 

Two superconducting crab cavities have been operated stably without any significant trouble for three years in KEKB since Feb/2007. At present (Dec/2009), maximum beam current with 'Crab ON' achieves 1200mA for HER (High Energy Ring, electron) and 1640mA for LER (Low Energy Ring, positron), respectively. RF trip rate per day due to crab cavity during 'physics run' was 2.8/day for HER and 0.4/day for LER at the beginning, and is 0.8/day for HER and 0.1/day for LER at present, respectively. Although Piezo actuator was frequently broken down at the beam abort with RF trip of the crab cavity, it was controlled stably by only LLRF (Low Level RF) feed-back system without Piezo actuator. Maximum HOM (Higher Order Mode) power, which is measured at HOM dampers made from ferrite, is 9.1kW for HER and 14.6kW for LER at the maximum beam current, respectively. LER crab voltage, which had suddenly dropped from 1.50MV to 1.10MV on March/2007, was gradually recovered from 1.14MV to 1.33MV in 2008.

 

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Slides

 
TUPEB001 Lattice Design and Study Tools Regarding the Super-B Project 1512
 
  • F. Méot
    CEA, Gif-sur-Yvette
  • N. Monseu
    LPSC, Grenoble Cedex
 
 

Lattice design tools are being developed, and related beam and spin dynamics simulations are being performed, in the framework of the international collaboration regarding the super-B project. The present contribution reports on this work.

 
TUPEB002 Design and Test of the Clearing Electrodes for e- loud Mitigation in the e+ DAΦNE Ring 1515
 
  • D. Alesini, A. Battisti, O. Coiro, T. Demma, S. Guiducci, V. Lollo, C. Milardi, P. Raimondi, M. Serio, R.S. Sorchetti, M. Zobov
    INFN/LNF, Frascati (Roma)
 
 

Metallic clearing electrodes have been designed to absorb the photo-electrons in the DAΦNE positron ring. They have been inserted in the wigglers and dipoles vacuum chambers and have been connected to external high voltage generators. In the paper we present the design of the devices and the results of the electromagnetic simulations related to both the transfer and longitudinal beam coupling impedances. We also present the results of the RF measurements and the first results with the DAΦNE circulating positron beam.

 
TUPEB003 The SuperB Project Accelerator Status 1518
 
  • M.E. Biagini, D. Alesini, R. Boni, M. Boscolo, T. Demma, A. Drago, M. Esposito, S. Guiducci, F. Marcellini, G. Mazzitelli, M.A. Preger, P. Raimondi, C. Sanelli, M. Serio, A. Stecchi, A. Stella, S. Tomassini, M. Zobov
    INFN/LNF, Frascati (Roma)
  • M.A. Baylac, J.-M. De Conto, Y. Gomez-Martinez, N. Monseu, D. Tourres
    LPSC, Grenoble
  • K.J. Bertsche, A. Brachmann, Y. Cai, A. Chao, M.H. Donald, A.S. Fisher, D. Kharakh, A. Krasnykh, N. Li, D.B. MacFarlane, Y. Nosochkov, A. Novokhatski, M.T.F. Pivi, J. Seeman, M.K. Sullivan, A.W. Weidemann, J. Weisend, U. Wienands, W. Wittmer, A.C. de Lira
    SLAC, Menlo Park, California
  • S. Bettoni
    CERN, Geneva
  • B. Bolzon, L. Brunetti, A. Jeremie
    IN2P3-LAPP, Annecy-le-Vieux
  • J. Bonis, G. Le Meur, B.M. Mercier, F. Poirier, C. Prevost, C. Rimbault, F. Touze, A. Variola
    LAL, Orsay
  • F. Bosi
    INFN-Pisa, Pisa
  • A. Chancé, F. Méot, O. Napoly
    CEA, Gif-sur-Yvette
  • R. Chehab
    IN2P3 IPNL, Villeurbanne
  • I. Koop, E.B. Levichev, S.A. Nikitin, P.A. Piminov, D.N. Shatilov, S.V. Sinyatkin
    BINP SB RAS, Novosibirsk
  • S.M. Liuzzo, E. Paoloni
    University of Pisa and INFN, Pisa
 
 

The SuperB project is an international effort aiming at building in Italy a very high luminosity e+e- (1036 cm-2 sec-1) asymmetric collider at the B mesons cm energy. The accelerator design has been extensively studied and changed during the past year. The present design, - based on the new collision scheme, with large Piwinski angle and the use of 'crab' sextupoles, which has been successfully tested at the DAPHNE Phi-Factory at LNF Frascati, - provides larger flexibility, better dynamic aperture and in the Low Energy Ring spin manipulation sections, needed for having longitudinal polarization of the electron beam at the Interaction Point. The Interaction Region has been further optimized in terms of apertures and reduced backgrounds in the detector. The injector complex design has been also updated. A summary of the design status, including details on lattice and spin manipulation will be presented in this paper.

 
TUPEB004 Super-B Lattice Studies 1521
 
  • Y. Nosochkov, W. Wittmer
    SLAC, Menlo Park, California
  • M.E. Biagini, P. Raimondi
    INFN/LNF, Frascati (Roma)
  • P.A. Piminov, S.V. Sinyatkin
    BINP SB RAS, Novosibirsk
 
 

The Super-B asymmetric e+e- collider is designed for 1036 cm-2sec-1 luminosity and beam energies of 6.7 and 4.18 GeV for e+ and e-, respectively. The machine will have the High and Low Energy Rings (HER and LER), and one Interaction Point (IP) with 60 mrad crossing angle. The INFN-LNF at Frascati is one of the proposed sites, and a lattice for short 1.3 km rings fitting to this site has been designed. The two rings are radially separated by 2 m except near the IP and in the dogleg on the opposite side of the rings. The injection sections and RF cavities are included. The lattice is optimized for a low emittance required for the desired high luminosity. Final Focus chromaticity correction is optimized for large transverse and energy acceptance. The "crab waist" sextupoles are included for suppression of betatron resonances induced at the IP collisions with large Piwinski angle. The LER spin rotator sections provide longitudinal polarization for the electron beam at IP. The lattice is flexible for tuning the design parameters and compatible with reusing the PEP-II magnets, RF cavities and other components. Design criteria and details on the lattice implementation are presented.

 
TUPEB005 High Luminosity Interaction Region Design for Collisions with Detector Solenoid 1524
 
  • C. Milardi, M.A. Preger, P. Raimondi, G. Sensolini, F. Sgamma
    INFN/LNF, Frascati (Roma)
 
 

An innovatory interaction region has been recently conceived and realized on the Frascati DAΦNE lepton collider. The concept of tight focusing and small crossing angle adopted until now to achieve high luminosity in multibunch collisions has evolved towards enhanced beam focusing at the interaction point with large horizontal crossing angle, thanks to a new compensation mechanism for the beam-beam resonances. The novel configuration has been tested with a small detector without solenoidal field yielding a remarkable improvement in term of peak as well as integrated luminosity. The high luminosity interaction region has now been modified to host a large detector with a strong solenoidal field integral which significantly perturbs the beam optics introducing new design challenges in terms of interaction region optics design, beam transverse coupling control and beam stay clear requirements.

 
TUPEB006 DAΦNE Developments for the KLOE-2 Experimental Run 1527
 
  • C. Milardi, D. Alesini, M.E. Biagini, C. Biscari, R. Boni, M. Boscolo, F. Bossi, B. Buonomo, A. Clozza, G.O. Delle Monache, T. Demma, E. Di Pasquale, G. Di Pirro, A. Drago, M. Esposito, A. Gallo, A. Ghigo, S. Guiducci, C. Ligi, F. Marcellini, G. Mazzitelli, L. Pellegrino, M.A. Preger, L. Quintieri, P. Raimondi, R. Ricci, U. Rotundo, C. Sanelli, M. Serio, F. Sgamma, B. Spataro, A. Stecchi, A. Stella, S. Tomassini, C. Vaccarezza, M. Zobov
    INFN/LNF, Frascati (Roma)
  • S. Bettoni
    CERN, Geneva
  • E.B. Levichev, S.A. Nikitin, P.A. Piminov, D.N. Shatilov
    BINP SB RAS, Novosibirsk
 
 

Recently the peak luminosity achieved on the DAΦNE collider has been improved by almost a factor 3 by implementing a novel collision scheme based on large Piwinski angle and Crab-Waist. This encouraging result opened new perspectives for physics research and a new run with the KLOE-2 detector has been scheduled to start by spring 2010. The KLOE-2 installation is a complex operation requiring a careful design effort and a several months long shutdown. The high luminosity interaction region has been deeply revised in order to take into account the effect on the beam caused by the solenoidal field of the experimental detector and to ensure background rejection. The shutdown has been also used to implement several other modifications aimed at improving beam dynamics: the wiggler poles have been displaced from the magnet axis in order to cancel high order terms in the field, the feedback systems have been equipped with stronger power supplies and more efficient kickers and electrodes have been inserted inside the wiggler and the dipole vacuum chambers, in the positron ring, to avoid the e-cloud formation. A low level RF feedback has been added to the cavity control in both rings.

 
TUPEB007 Low Emittance Tuning Studies for SuperB 1530
 
  • S.M. Liuzzo
    University of Pisa and INFN, Pisa
  • M.E. Biagini, P. Raimondi
    INFN/LNF, Frascati (Roma)
  • M.H. Donald
    SLAC, Menlo Park, California
 
 

SuperB is an international project for an asymmetric 2 rings collider at the B mesons cm energy to be built in the Rome area in Italy. The two rings will have very small beam sizes at the Interaction Point and very small emittances, similar to the Linear Collider Damping Rings ones. In particular, the ultra low vertical emittances, 7 pm in the LER and 4 pm in the HER, need a careful study of the misalignment errors effects on the machine performances. Studies on the closed orbit, vertical dispersion and coupling corrections have been carried out in order to specify the maximum allowed errors and to provide a procedure for emittance tuning. A new tool which combines MADX and Matlab routines has been developed, allowing for both corrections and tuning. Results of these studies are presented.

 
TUPEB009 Installation of Skew Sextupole Magnets at KEKB 1533
 
  • M. Masuzawa, K. Egawa, T. Kawamoto, Y. Ohsawa, T. Sueno, N. Tokuda
    KEK, Ibaraki
 
 

A new set of magnets, skew sextupole magnets, were designed, manufactured, measured and installed during the winter shutdown of 2009. Twenty magnets were installed in the HER and eight magnets were installed in the LER. It was a challenging job for the magnet group to design, manufacture, measure the magnetic field and install them in the tunnel in just three months. Much effort to finish the installation in time and reduce the production cost was made at every step of the entire process. With these newly installed skew sextupole magnets, a significant luminosity boost was achieved. The production and installation of the skew sextupole magnets are described in this report.

 
TUPEB011 KEKB Superconducting Accelerating Cavities and Beam Studies for Super-KEKB 1536
 
  • Y. Morita, K. Akai, T. Furuya, A. Kabe, S. Mitsunobu, M. Nishiwaki, S. Takano
    KEK, Ibaraki
 
 

Eight superconducting accelerating cavities have been stably operated in the KEKB with sufficiently low trip rates. Two superconducting crab cavities were installed in 2007 and soon the crab crossing operation started. Recently the KEKB luminosity reached the world record of 2.1 x 1034 cm-1s-1. Stable operations of the accelerating cavities contributed for the luminosity increase. For the future Super-KEKB, we are developing a high power coupler for an input power of 600 kW and a HOM damper for RF power absorption more than 30 kW. The Super-KEKB requires RF operations with the high beam loading and the low RF voltage than the present KEKB operation. To suppress klystron output powers the external Q value has to be reduced. A new operation was proposed for superconducting cavities. In order to keep high RF voltages in each cavity, some cavities reverse its synchronous beam phase while the total RF voltage is kept as low as the required one. Beam studies were successfully carried out with one cavity reversed its synchronous beam phase.

 
TUPEB012 Optics Measurement at the Interaction Point using Nearby Position Monitors in KEKB 1539
 
  • K. Ohmi, T. Ieiri, Y. Ohnishi, Y. Seimiya, M. Tejima, M. Tobiyama, D.M. Zhou
    KEK, Ibaraki
 
 

Optics parameters at the interaction point, beta, x-y coupling, dispersion and their chromatic aberrations, seriously affect the beam-beam performance as is shown in experiments and simulations. The control of the optics parameters is essential to maintain the high luminosity in KEKB. They drift day by day, or before and after the beam abort. They were often monitored at intervals of the operation with taking the study time. They are recently measured during the physics run using a pilot bunch without collision. We show the measured the optics parameters and their variations and discuss the relation to the luminosity.

 
TUPEB013 Strong-strong Simulation for Super B Factories 1542
 
  • K. Ohmi
    KEK, Ibaraki
 
 

Super B factories are designed with very low emittance and very low beta function at the interaction point. The two beams collide with a large crossing angle, thus the overlap area of the beams is limited at a small part of their length. Simulation of the beam-beam effects is hard because of the longitudinal slice of the beam is the order of 100. We discuss two methods for the simulation. One is a simplified method, which is mixture of the particle in cell and Gaussian approximation. The other is fully strong-strong simulation using the particle in cell. The shifted Green function is used to calculate the beam-beam force for less overlap of the beam distribution. Luminosity and its degradation due to IP optics errors in Super B factories are discussed.

 
TUPEB017 Effects of Linear and Chromatic X-Y Couplings in the SuperKEKB 1551
 
  • D.M. Zhou, H. Koiso, A. Morita, K. Ohmi, Y. Ohnishi, Y. Seimiya
    KEK, Ibaraki
 
 

Using a weak-strong beam-beam code, in which the symplectic maps for the linear coupling and chromatic aberrations were implemented, the luminosity degradation caused by the linear and chromatic X-Y couplings at the interaction point (IP) were evaluated for the SuperKEKB project under design. The linear and chromatic X-Y couplings were estimated through modeling the machine errors using random seeds, based on a baseline design of the SuperKEKB rings. It was found that the linear and chromatic X-Y couplings can potentially degrade the luminosity performance.

 
TUPEB019 Evaluation of the Detector BG for SuperKEKB 1557
 
  • M. Iwasaki, Y. Funakoshi, J. Haba, N. Iida, K. Kanazawa, H. Koiso, Y. Ohnishi, K. Shibata, S. Tanaka, T. Tsuboyama, S. Uno, Y. Ushiroda
    KEK, Ibaraki
  • H. Aihara, C. Ng, S. Sugihara
    University of Tokyo, Tokyo
  • H. Nakano, H. Yamamoto
    Tohoku University, Graduate School of Science, Sendai
 
 

SuperKEKB is the upgrade plan of the current B-factory experiment with the KEKB accelerator at KEK. Its luminosity is designed to be 8x1035 /cm2/s (40 times higher than KEKB) and the integrated luminosity is expected to be 50 ab-1. In SuperKEKB, it is important to evaluate the beam induced BG and design the interaction region (IR) to assure the stable detector operation. To estimate the beam induced BG, we construct the beam-line simulation based on the GEANT4 simulation. In this paper, we report the BG evaluation and the IR design for SuperKEKB.

 
TUPEB020 Beam Dynamic Issues in the BEPCII Luminosity Commissioning 1560
 
  • Q. Qin, N. Huang, D. Ji, Y. Jiao, Y.D. Liu, Y.M. Peng, D. Wang, J.Q. Wang, N. Wang, X.H. Wang, Y. Wei, X.M. Wen, J. Xing, G. Xu, C.H. Yu, C. Zhang, Y. Zhang
    IHEP Beijing, Beijing
  • Z. Duan
    IHEP Beiing, Beijing
 
 

As a tau-charm factory like collider, the upgrade project of the Beijing Electron Positron Collider (BEPCII), has reached its first design value of luminosity. During the commissioning of its luminosity, beam optics recovery, machine parameters measurement, detector solenoid compensation, and instability cure are main problems we met. Besides commissioning the machine, beams were delivered to the users from high energy physics and synchrotron radiation. This paper summarizes the accelerator physics issues in the BEPCII luminosity commissioning.


Supported by National Natural Sciences Foundation of China (10725525)

 
TUPEB021 Conceptual Design of the Muon Collider Ring Lattice 1563
 
  • Y. Alexahin, E. Gianfelice-Wendt, A.V. Netepenko
    Fermilab, Batavia
 
 

Muon collider is a promising candidate for the next energy frontier machine. However, in order to obtain peak luminosity in the 1035/cm2/s range the collider lattice design must satisfy a number of stringent requirements, such as low beta at IP (beta*<1 cm), large momentum acceptance and dynamic aperture and small value of the momentum compaction factor. Here we present a particular solution for the interaction region optics whose distinctive feature is a three-sextupole local chromatic correction scheme. Together with a new flexible momentum compaction arc cell design this scheme allows to satisfy all the above-mentioned requirements and is relatively insensitive to the beam-beam effect.

 
TUPEB022 Muon Collider Interaction Region Design 1566
 
  • Y. Alexahin, E. Gianfelice-Wendt, V. Kashikhin, N.V. Mokhov, A.V. Zlobin
    Fermilab, Batavia
  • V.Yu. Alexakhin
    JINR, Dubna, Moscow Region
 
 

Design of a muon collider interaction region (IR) presents a number of challenges arising from low beta* < 1 cm, correspondingly large beta-function values and beam sizes at IR magnets, as well as the necessity to protect superconducting magnets and collider detectors from muon decay products. As a consequence, the designs of the IR optics, magnets and machine-detector interface are strongly interlaced and iterative. A consistent solution for the 1.5 TeV c.o.m. muon collider IR is presented. It can provide an average luminosity of 1034/cm2/s with an adequate protection of magnet and detector components.

 
TUPEB023 High Gradient Final Focusing Quadrupole for a Muon Collider 1569
 
  • S.A. Kahn, G. Flanagan, R.P. Johnson
    Muons, Inc, Batavia
 
 

To achieve the high luminosity required for a muon collider strong quadrupole magnets will be needed for the final focus in the interaction region. These magnets will be located in regions with space constraints imposed both by the lattice and the collider detector. There are significant beam related backgrounds from muon decays and synchrotron radiation which create unwanted particles which can deposit significant energy in the magnets of the final focus region of the collider. This energy deposition results in the heating of the magnet which can cause it to quench. To mitigate the effects of heating from the energy deposition shielding will need to be included within the magnet forcing the aperture to be larger than desired and consequently reducing the gradient. We propose to use exotic high magnetization materials for pole tips to increase the quadrupole gradient.

 
TUPEB024 Solenoid Compensation for the SuperB Interaction Region 1572
 
  • K.J. Bertsche, M.K. Sullivan
    SLAC, Menlo Park, California
 
 

We present an approach for compensating adverse effects of the detector solenoid in the SuperB Interaction Region (IR). We place compensating solenoids around the IR quadrupole magnets to reduce the magnetic fields nearly to zero. This allows more operational headroom for superconducting IR magnets and avoids saturation of ferric IR magnets. We place stronger compensating solenoids between IR magnets to reverse the magnetic field direction. This allows adjusting the total integrated solenoid field to zero, which eliminates coordinate plane rotation and reduces vertical beam displacements in the IR.

 
TUPEB025 Polarimetery for SuperB 1575
 
  • M.K. Sullivan, R.C. Field, K. C. Moffeit, Y. Nosochkov, U. Wienands, W. Wittmer, M. Woods
    SLAC, Menlo Park, California
 
 

We present a conceptual design for a polarimeter based on Compton scattering of laser light on the electron beam for the Super-B accelerator proposed for Frascati, Italy. The accelerator design has polarized electrons in the low-energy ring (4.18 GeV). We want to measure the polarization of every bunch every few seconds using a laser with 119 Mhz repetition rate. The spin rotator section has a second point between the solenoids and interaction point where the polarization is nearly longitudinal with helicity opposite to that found at the interaction point. We plan to use this point to measure the polarization as the possible location near the interaction point has too much background from the collision. We show the area in the accelerator where the polarimeter would be installed and describe the laser as well as the detectors for the Compton scattered electrons and photons.

 
TUPEB026 Beam Fields and Energy Dissipation inside the Be Beam Pipe of the Super-B Detector 1578
 
  • A. Novokhatski, M.K. Sullivan
    SLAC, Menlo Park, California
 
 

We study the bunch field diffusion and energy dissipation in the beam pipe of the Super-B detector, which consists of two coaxial Be thin pipes (half a millimeter). Cooling water will run between these two pipes. Gold and nickel will be sputtered (several microns) onto the beryllium pipe. The Maxwell equations for the beam fields in these thin layers are solved numerically for the case of infinite pipes. We also calculate the amplitude of electromagnetic fields outside the beam pipe, which may be noticeable as the beam current can reach 4 A in each beam. Results of simulations are used for the design of this central part of the Super-B detector.

 
TUPEB027 A New Interaction Region Design for the Super-B Factory 1581
 
  • M.K. Sullivan, K.J. Bertsche
    SLAC, Menlo Park, California
  • S. Bettoni
    CERN, Geneva
  • E. Paoloni
    University of Pisa and INFN, Pisa
  • P. Raimondi
    INFN/LNF, Frascati (Roma)
  • P. Vobly
    BINP SB RAS, Novosibirsk
 
 

A final focus magnet design that uses super-ferric magnets is introduced for the Super-B interaction region. The baseline design has air-core super-conducting quadrupoles. This idea instead uses super-conducting wire in an iron yoke. The iron is in the shape of a Panofsky quadrupole and this allows for two quadrupoles to be side-by-side with no intervening iron as long as the gradients of the two quads are equal. This feature allows us to move in as close as possible to the collision point and minimize the beta functions in the interaction region. The super-ferric design has advantages as well as drawbacks and we will discuss these in the paper.

 
TUPEB029 Polarization in SuperB 1587
 
  • U. Wienands, Y. Nosochkov, M.K. Sullivan, W. Wittmer
    SLAC, Menlo Park, California
  • D.P. Barber
    Cockcroft Institute, Warrington, Cheshire
  • M.E. Biagini, P. Raimondi
    INFN/LNF, Frascati (Roma)
  • I. Koop, S.A. Nikitin, S.V. Sinyatkin
    BINP SB RAS, Novosibirsk
 
 

The availability of longitudinally polarized electrons is an important aspect of the design of the proposed SuperB project at LNF Frascati. Spin rotators are an integral part of the design of the Interaction Region (IR). We have chosen a solenoid-dipole design; at the 4.18 GeV nominal energy this is more compact that a design purely based on dipole magnets. Integration with the local chromaticity correction of the ultra-low beta* IR has been achieved. The spin rotators are symmetric about the Interaction Point, this design saves a significant amount of length as the dipoles become a part of the overall 360 deg. bend. The layout leaves limited opportunity to setup the optics for minimum depolarization; this is acceptable since beam life time in SuperB at high luminosity is only about 5 min and up-to 90% polarized electrons will be injected continuously. In this way an average beam polarization of about 70% is maintained. Simulations and analytic estimates with the DESY code SLICKTRACK and other codes indicate such operation is feasible from a spin-dynamics point of view. The paper will discuss the overall spin-rotator design as well as the spin dynamics in the ring.

 
WEXMH01 Status and Performance of BEPCII 2359
 
  • Q. Qin, L. Ma, J.Q. Wang, C. Zhang
    IHEP Beijing, Beijing
 
 

BEPCII is the upgrade project of the Beijing Electron Positron Collider (BEPC) with its design luminosity of 1x1033cm-2s-1 @1.89 GeV. The construction of BEPCII was completed in May 2008. The collider has been operated for high energy physics experiments since February 2009 with 1/5 of design luminosity at psi(3680). The luminosity has been steadily increased during the operation. Status and updated performance of BEPCII will be reported.

 

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WEOAMH01 Beam Tests of a Clearing Electrode for Electron Cloud Mitigation at KEKB Positron Ring 2369
 
  • Y. Suetsugu, H. Fukuma, K. Shibata
    KEK, Ibaraki
  • M.T.F. Pivi, L. Wang
    SLAC, Menlo Park, California
 
 

In order to mitigate the electron cloud instability (ECI) in a positron ring, an electron clearing electrode with a very thin structure has been developed. The electrode has been tested with an intense positron beam of the KEKB B-factory using a test chamber. A drastic reduction in the electron density around the beam was demonstrated in a dipole magnetic field (0.78 T). The clearing electrode was then applied to the actual copper beam pipe (94 mm in diameter) with antechambers for wiggler magnets of KEKB. The feed-through was revised to improve reliability, and the length was modified to fit a real magnet. The input power into the electrode was estimated to be approximately 80 W/m. The clear reduction in the electron density was also observed by applying a voltage of +500 V to the electrode. The design of clearing electrodes has now reached a high reliability and it is suitable for accelerator applications.

 

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WEOAMH02 Recent Progress of KEKB 2372
 
  • Y. Funakoshi, T. Abe, K. Akai, Y. Cai, K. Ebihara, K. Egawa, A. Enomoto, J.W. Flanagan, H. Fukuma, K. Furukawa, T. Furuya, J. Haba, T. Ieiri, N. Iida, H. Ikeda, T. Ishibashi, M. Iwasaki, T. Kageyama, S. Kamada, T. Kamitani, S. Kato, M. Kikuchi, E. Kikutani, H. Koiso, M. Masuzawa, T. Mimashi, T. Miura, A. Morita, T.T. Nakamura, K. Nakanishi, M. Nishiwaki, Y. Ogawa, K. Ohmi, Y. Ohnishi, N. Ohuchi, K. Oide, T. Oki, M. Ono, M. Satoh, Y. Seimiya, K. Shibata, M. Suetake, Y. Suetsugu, T. Sugimura, Y. Susaki, T. Suwada, M. Tawada, M. Tejima, M. Tobiyama, N. Tokuda, S. Uehara, S. Uno, Y. Yamamoto, Y. Yano, K. Yokoyama, M. Yoshida, S.I. Yoshimoto, D.M. Zhou, Z.G. Zong
    KEK, Ibaraki
 
 

KEKB is an e-/e+ collider for the study of B physics and is also used for machine studies for future machines. The peak luminosity of KEKB, which is the world-highest value, has been still increasing. This report summarizes recent progress at KEKB.

 

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FRXBMH01 Next Generation B-factories 4764
 
  • M. Masuzawa
    KEK, Ibaraki
 
 

The KEKB and PEP-II B factories have achieved world record luminosities while doubling or tripling their original design luminosities. The demand now from the physics community is for Super B Factories with orders of magnitude higher luminosities than those achieved by the present generation of machines. This talk will discuss the next-generation B factories, which aim to push back the luminosity frontier in the search for physics beyond the Standard Model.

 

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