• T. Sakai, M. Ikeda, S. Ohsawa, T. Sugimura
  KEK, Ibaraki
• N. Sakabe
  FAIS, Akatsuka, Tsukuba, Ibaraki

A new type of rotating anticathode X-ray generator has been developed, in which the electron beam irradiates the inner surface of a U-shaped Cu anticathode. A high-flux electron beam is focused on the inner surface of the anticathode by optimizing the geometry of the bending magnet. In order to minimize the sizes of the X-ray source, the electron beam is focused in a short distance by the combined function magnets. A shape on the surface of the bending magnet was determined by simulation. The beam trajectories and bending magnet were optimized by the General Particle Tracer(GPT) and Opera-3D code simulation. The result of simulation clearly shows that the bending magnet gap surface angle parameters are important to the beam focused in a short distance. FWHM sizes of the beam from the simulation were obtained to be 0.45mm(horizontal) and 0.05mm(vertical) of which the anticathode with a beam voltage and current were 120kV and 75mA, respectively. The effective brilliance to be about 500kW/mm² simulated predict that with the supposition of a two-dimensional Gaussian distribution. In this paper, the optimization of the focusing magnet and the results of the prototype test are reported.

• T. Sugimura, M. Akemoto, D.A. Arakawa, A. Enomoto, S. Fukuda, K. Furukawa, T. Higo, H. Honma, M. Ikeda, E. Kadokura, K. Kakihara, T. Kamitani, H. Katagiri, M. Kurashina, S. Matsumoto, T. Matsumoto, H. Matsushita, S. Michizono, K. Mikawa, T. Miura, H. Nakajima, K. Nakao, Y. Ogawa, S. Ohsawa, M. Satoh, T. Shidara, A. Shirakawa, T. Suwada, T. Takenaka, Y. Yano, K. Yokoyama, M. Yoshida
  KEK, Ibaraki

The next generation B-factory 'SuperKEKB' project whose target luminosity is 8 ×10³⁵ cm^-2s^-1 is under consideration. A 'nano-beam scheme' is introduced to the SuperKEKB. In the scheme, an electron beam (Energy = 7 GeV, Charge = 3-4 nC/bunch, Vertical emittance =2.8 x 10^-5 m) and a positron beam (Energy = 4 GeV, Charge = 4 nC/bunch, Vertical emittance = 1.6 x 10^-5 m), are required at the end of injector linac. They are quite challenging targets for the present linac. In order to meet the requirements, we will introduce some new components to the linac. They are a photo-cathode RF gun for an electron beam, a positron capture section using new L-band cavities, a newly designed positron-generation target system and a damping ring for a positron beam. This presentation shows a strategy of our injector upgrade.