Author: Lilje, L.
Paper Title Page
TUPPR051 Development of L-Band Positron Capture Accelerating Structure with Kanthal-coated Collinear Load for SuperKEKB 1933
  • F. Miyahara, Y. Arakida, T. Higo, N. Iida, K. Kakihara, T. Kamitani, S. Matsumoto
    KEK, Ibaraki, Japan
  • L. Lilje
    DESY, Hamburg, Germany
  In order to achieve a luminosity of 8x1035 cm-2 s-1, the SuperKEKB injector is required to provide both e+e beams higher in intensity by a factor 4-5 than those for KEKB, and with a low emittance of about 20 um. A damping ring is used to fulfill this low emittance requirement for e+, but the intensity increase is realized by a larger yield from the conversion target to the damping ring. To this end, the L-band capture system is adopted to increase the transverse and longitudinal acceptance. The capture section consists of a Tungsten conversion target with flux concentrator followed by two L-band 2.4m-long accelerating structures and continuing to the large aperture S-band 2m-long ones. The L-band frequency of 1.3 GHz, 5/11 times S-band one, was adopted to suppress the satellite bunches in the S-band system. This L-band system is surrounded by a solenoid magnet producing 4kG on axis. To compose compact magnet system, the output coupler of the L-band accelerating structure is replaced by the Kanthal coated collinear load section. In this paper, we will discuss the design of the accelerating structure and present the studies of Kanthal layer coated on copper.