• 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