| Paper |
Title |
Page |
| MOP008 |
Design and Performance of Optics for Multi-Energy Injector Linac
|
46 |
| |
- Y. Ohnishi, K. Furukawa, N. Iida, T. Kamitani, M. Kikuchi, Y. Ogawa, M. Satoh, K. Yokoyama
KEK, Ibaraki
|
|
| |
Injector linac provides injection beams for four storage rings, KEKB high energy electron ring (HER), KEKB low energy positron ring (LER), PF-AR electron ring, and PF electron ring. The injection beams for these rings have different energies and intensities. Recently, a requirement of simultaneous injection among these rings arises to make a top-up injection possible. Magnetic fields of DC magnets to confine the beam to the accelerating structures can not be changed between pulse to pulse, although the beam energy can be controlled by fast rf phase shifters of klystrons. This implies that common magnetic fields of bending magnets and quadrupole magnets should be utilized to deliver beams having different characteristics. Therefore, we have designed multi-energy optics for KEKB high energy electron ring (8 GeV, 1 nC/pulse) and PF electron ring (2.5 GeV, 0.1 nC/pulse) and present a performance of the multi-energy injector linac.
|
|
| MOP025 |
Study on High-Current Multi-Bunch Beam Acceleration for KEKB Injector Linac
|
91 |
| |
- M. Yoshida, H. Katagiri, Y. Ogawa
KEK, Ibaraki
|
|
| |
The KEKB injector linac is usually operated to accelerate only two 10 nC electron bunches to generate positron, since more bunch cannot be equalized the beam energy using the conventional pulse compressor (SLED) and the simple phase modulation. The aim of this study is to find how to accelerate more bunches without any modification of high power RF distribution. One way is that a part of the acceleration units is used to compensate the beam energy difference. On the other hand, the recent electron linac is designed for the multi-bunch operation by compensating the beam loading. And this beam loading compensation method is usually realized by combining the output power of two or more klystrons. However our linac system consists of one 50 MW klystron in one acceleration unit, and eight klystrons are driven by a 100kW klystron. Another way to realize the multi-bunch acceleration in our linac is using the amplitude modulation of the klystron. This is realized using the I-Q modulation of the low level RF considering the non-linear characteristics of the total amplification system including klystrons. Further we developed a FPGA board with 100 MHz DACs and ADCs to realize this.
|
|