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Takayama, K.

Paper Title Page
MOPC156 ECR Ion Source for the KEK All-ion Accelerator 442
 
  • H. Suzuki, Y. Arakida, T. Iwashita, M. Kawai, T. Kono, K. Takayama
    KEK, Ibaraki
  • S. I. Inagaki
    Kyushu University
  • K. Okazaki
    Nippon Advanced Technology Co. Ltd., Ibaraki-prefecture
 
  R&D works to realize an all-ion accelerator (AIA)* -capable of accelerating all ions of any possible charge state, based on the induction synchrotron concept, which was demonstrated using the KEK 12 GeV-PS**, are going on. As an ion source for the KEK-AIA, an electron cyclotron resonance (ECR) ion source has been developed. Permanent magnets made of NdFeB to generate a cusp field and 9.4 GHz microwave to energize plasma electrons have been employed. The microwave power of 750 W generated in a traveling wave tube is focused into the interaction region with a horn antenna. Regarding the cut off density for 9.4 GHz, the vacuum and the gas feeding system has been designed. The base pressure of 1·10-5 Pa is reached with a single turbo molecular pump of 300 l/min, and the gas flow rate less than 1 cc/min is maintained with a mass flow controller. The plasma chamber is water-cooled against Joule heating. The geometry of the extraction electrodes and the downstream transport line have been optimized by IGUN simulations. The whole system will be embedded in the high voltage terminal box of 200 kV. Details of the design and the preliminary test will be described at this conference.

*K. Takayama, Y. Arakida, T. Iwashita, Y. Shimosaki, T. Dixit, and K. Torikai, J. of Appl. Phys. 101, 063304 (2007).
**K. Takayama et al., Phys. Rev. Lett. 98, 054801 (2007).

 
WEPP129 Digital Acceleration Scheme of the KEK All-ion Accelerator 2797
 
  • T. S. Dixit
    GUAS/AS, Ibaraki
  • Y. Arakida, T. Iwashita, K. Takayama
    KEK, Ibaraki
 
  R&D works to realize an all-ion accelerator (AIA)*-capable of accelerating all ions of any possible charge state, based on the induction synchrotron concept, which was demonstrated using the KEK 12 GeV-PS in 2006 **, is going on. In the induction synchrotron, unlike an RF synchrotron, operational performance is not limited due to the frequency band-width, since the switching power supply to energize the induction acceleration system is triggered by signals obtained from the bunch monitor. For a POP experiment of AIA, argon ions will be accelerated in the KEK-500 MeV booster ring, a Rapid Cycle Synchrotron (f=20 Hz) and the RCS requires a dynamic change in the acceleration voltage. Since the induction acceleration voltage per pulse is fixed, a novel technique combining the pulse density control and intermittent operation of multi-acceleration cells has been proposed. The acceleration scheme of the AIA fully employing this technique was verified by computer simulation and demonstrated at our test facility, where a new induction acceleration cell generating an acceleration voltage pulse of 2 μsec long was triggered by a beam simulator to mimic a circulating Ar beam in the KEK-AIA

* K. Takayama, Y. Arakida, T. Iwashita, Y. Shimosaki, T. Dixit, K. Torikai, J. of Appl. Phys. 101, 063304 (2007).
**K. Takayama et al., Phys. Rev. Lett. 98, 054801 (2007).

 
THPC107 Beam Dynamical Issues of the KEK All-ion Accelerator 3227
 
  • K. Takayama, T. Adachi, E. Nakamura, H. Someya
    KEK, Ibaraki
 
  R&D works to realize an all-ion accelerator (AIA)* capable of accelerating all species of ions with any possible charge state, based on the induction synchrotron concept, which was demonstrated using the KEK 12 GeV-PS in 2006**, are going on at KEK. The KEK AIA, which is a modification of the existing KEK 500 MeV Booster Ring of a rapid cycle synchrotron, may be an injector-free accelerator. An ion beam from the high-voltage terminal of 200 kV is directly injected into the accelerator ring. Several key issues associated with the low energy injection must be addressed. Space-charge limited current due to a small relativistic b and a short life-time due to scattering with the residual molecules and eddy-current induced magnetic fields associated with guide-fields ramping from a low field level are among them. Careful considerations on them suggest that there are significant constrains on the operational performance and gives achievable beam parameters assuming the present parameters of the KEK AIA.

*K. Takayama, Y. Arakida, T. Iwashita, Y. S himosaki, T. Dixit, K. Torikai, J. of Appl. Phys. 101, 063304 (2007).
**K. Takayama et al., Phys. Rev. Lett. 98, 054801 (2007).