• M. Tawada, Y. Funakoshi, M. Iwasaki, H. Koiso, A. Morita, Y. Ohnishi, N. Ohuchi, K. Oide, K. Tsuchiya, Z.G. Zong
  KEK, Ibaraki

KEK is studying the design of the interaction region quadrupoles for the SuperKEKB of which the two beams of 4GeV/7GeV for LER/HER have a crossing angle of 83 mrad. For each beam, the final beam focusing system consisting of superconducting and permanent magnets is studied. The superconducting quadrupoles close to the interaction point for each beam are located in the compensation superconducting solenoid which cancels the solenoid field by the particle detector, Belle. These magnet parameters are optimized to obtain higher luminosity. In this paper, the design progress of final focusing system and magnets will be reported.

• K. Ohmi, H. Koiso
  KEK, Ibaraki

Progress of Graphic Processor Unit (GPU) is marveled. The performance is 1TFlops per unit. Simulation of electron gun can be performed by particle-particle interactions, in which the calculation cost is NxN. Since the calculation of each interaction is very simple, GPU can demonstrate its ability. We show simulation results and discuss the possibilities to extend other simulations.

• 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.

• 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.

• 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.

Slides