Paper |
Title |
Page |
TUPPR005 |
Linac Upgrade in Intensity and Emittance for SuperKEKB |
1819 |
|
- T. Higo, M. Akemoto, D.A. Arakawa, Y. Arakida, A. Enomoto, S. Fukuda, K. Furukawa, Y. Higashi, H. Honma, N. Iida, M. Ikeda, E. Kadokura, K. Kakihara, T. Kamitani, H. Katagiri, M. Kurashina, S. Matsumoto, T. Matsumoto, H. Matsushita, S. Michizono, K. Mikawa, T. Miura, F. Miyahara, T. Mori, H. Nakajima, K. Nakao, T. Natsui, Y. Ogawa, S. Ohsawa, M. Satoh, T. Shidara, A. Shirakawa, H. Sugimoto, T. Suwada, T. Takatomi, T. Takenaka, Y. Yano, K. Yokoyama, M. Yoshida, L. Zang, X. Zhou
KEK, Ibaraki, Japan
- D. Satoh
TIT, Tokyo, Japan
|
|
|
The SuperKEKB is designed to produce 40 times luminosity than that of the KEKB. In order to realize such a high luminosity, the injector linac should provide both electron and positron beams of about 4-5 nC/bunch, which is several times higher than before. In addition, their emittance requirement of the injection beam to the rings is 20 microns, which is a factor of a few tens smaller than before. The intensity and emittance of the electron beam are realized directly by developing the photo RF gun. In contrast, the positron intensity is increased by adopting a higher capture efficiency system with flux concentrator followed by large-aperture accelerators, while its emittance is reduced by a damping ring. For preserving such a low emittance of both beams toward the injection to the rings, the suppression of the emittance growth is crucial. To this end, the alignment of the accelerator components should be a few tens of microns, where we need an improvement by more than a factor 10. The beam-based alignment is definitely needed with better-resolution BPMs. In the present paper are reviewed the overall progress and perspective of the design and the associated component developments.
|
|
|
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.
|
|
|
THPPC022 |
Enhanced Coupling Design of a Detuned Damped Structure for CLIC |
3323 |
|
- A. D'Elia, A. Grudiev, V.F. Khan, W. Wuensch
CERN, Geneva, Switzerland
- T. Higo
KEK, Ibaraki, Japan
- R.M. Jones
UMAN, Manchester, United Kingdom
|
|
|
The key feature of the improved coupling design in the Damped Detuned Structure (DDS) is focused on the four manifolds. Rectangular geometry slots and rectangular manifolds are used. This results in a significantly stronger coupling to the manifolds compared to the previous design. We describe the new design together with its wakefield damping properties.
|
|
|