IPAC2011 - List of Authors (Nakanishi, H.)

Paper

Title

Page

KEK Digital Accelerator and its Beam Commissioning

1920

K. Takayama, T. Arai, Y. Arakida, M. Hasimoto, T. Iwashita, E. Kadokura, T. Kawakubo, T. Kubo, H. Nakanishi, K. Okamura, H. Someya, A. Takagi, M. Wake
KEK, Ibaraki, Japan
T. Adachi, K.W. Leo
Sokendai, Ibaraki, Japan
K. Okazaki
Nippon Advanced Technology Co. Ltd., Ibaraki-prefecture, Japan

The digital accelerator (DA), which is a small-scale induction synchrotron no requiring a high-energy injector accelerator and capable of providing a wide variety of ions, has been constructed at KEK*. Since the last winter beam commissioning has been carried out. Preliminary results of the beam commissioning experiment as well as the accelerator itself will be presented at the conference. The KEK-DA consists of a 200 kV high voltage terminal, in which an ECRIS is embedded, 15 m long LEBT, electro-static injection kicker, and a 10 Hz rapid cycle synchrotron, which is the recycle use of the former 500 MeV Booster synchrotron. An ion pulse, which is chopped in 5 μs by the newly developed Marx generator driven chopper**, is guided through the LEBT and injected by the electrostatic kicker, which is turned off before the injected ion pulse completes the first turn. Then the ion pulse is captured with a pair of barrier voltages and accelerated with the induction acceleration voltage through a full acceleration period. Beam commissioning has been started with a He¹⁺ ion beam of 50 micro-ampere. Beam commissioning of other ions such as C, N, O, Ne, and Ar will be expected.
* T. Iwashita et al., “KEK Digital Accelerator”, Phys. Rev. ST-AB, published in 2011.
** T.Adachi et al., “A Solid-State Marx Generator Driven Einzel Lens Chopper”, these proceedings.

Slides WEOBA02 [4.268 MB]

WEPS025

First Beam Experiments at ISIS with a Low Output-impedance Second Harmonic Cavity

2538

Y. Irie, S. Fukumoto, K. Muto, H. Nakanishi, T. Oki, A. Takagi
KEK, Ibaraki, Japan
D. Bayley, I.S.K. Gardner, R.J. Mathieson, A. Seville, J.W.G. Thomason
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
J.C. Dooling, D. Horan, R. Kustom
ANL, Argonne, USA
M.E. Middendorf
ORNL RAD, Oak Ridge, Tennessee, USA

A Low Output-Impedance (LOI) rf drive, which may be suitable for future high intensity accelerator applications, has been developed jointly by ANL, ISIS and KEK for an ISIS synchrotron second harmonic cavity. The cavity is ferrite-loaded, and is driven by a high-power triode (240 kW plate dissipation) with a plate-to-grid feedback circuit. The impedance is designed to be 20~30 ohms over a 2-6 MHz frequency range. Beam induced voltage has been measured with the ISIS beam, and compared with that calculated from the designed output impedance.

Paper	Title	Page
WEOBA02	KEK Digital Accelerator and its Beam Commissioning	1920
	K. Takayama, T. Arai, Y. Arakida, M. Hasimoto, T. Iwashita, E. Kadokura, T. Kawakubo, T. Kubo, H. Nakanishi, K. Okamura, H. Someya, A. Takagi, M. Wake KEK, Ibaraki, Japan T. Adachi, K.W. Leo Sokendai, Ibaraki, Japan K. Okazaki Nippon Advanced Technology Co. Ltd., Ibaraki-prefecture, Japan
	The digital accelerator (DA), which is a small-scale induction synchrotron no requiring a high-energy injector accelerator and capable of providing a wide variety of ions, has been constructed at KEK. Since the last winter beam commissioning has been carried out. Preliminary results of the beam commissioning experiment as well as the accelerator itself will be presented at the conference. The KEK-DA consists of a 200 kV high voltage terminal, in which an ECRIS is embedded, 15 m long LEBT, electro-static injection kicker, and a 10 Hz rapid cycle synchrotron, which is the recycle use of the former 500 MeV Booster synchrotron. An ion pulse, which is chopped in 5 μs by the newly developed Marx generator driven chopper, is guided through the LEBT and injected by the electrostatic kicker, which is turned off before the injected ion pulse completes the first turn. Then the ion pulse is captured with a pair of barrier voltages and accelerated with the induction acceleration voltage through a full acceleration period. Beam commissioning has been started with a He¹⁺ ion beam of 50 micro-ampere. Beam commissioning of other ions such as C, N, O, Ne, and Ar will be expected. T. Iwashita et al., “KEK Digital Accelerator”, Phys. Rev. ST-AB, published in 2011. ** T.Adachi et al., “A Solid-State Marx Generator Driven Einzel Lens Chopper”, these proceedings.
	Slides WEOBA02 [4.268 MB]

WEPS025	First Beam Experiments at ISIS with a Low Output-impedance Second Harmonic Cavity	2538
	Y. Irie, S. Fukumoto, K. Muto, H. Nakanishi, T. Oki, A. Takagi KEK, Ibaraki, Japan D. Bayley, I.S.K. Gardner, R.J. Mathieson, A. Seville, J.W.G. Thomason STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom J.C. Dooling, D. Horan, R. Kustom ANL, Argonne, USA M.E. Middendorf ORNL RAD, Oak Ridge, Tennessee, USA
	A Low Output-Impedance (LOI) rf drive, which may be suitable for future high intensity accelerator applications, has been developed jointly by ANL, ISIS and KEK for an ISIS synchrotron second harmonic cavity. The cavity is ferrite-loaded, and is driven by a high-power triode (240 kW plate dissipation) with a plate-to-grid feedback circuit. The impedance is designed to be 20~30 ohms over a 2-6 MHz frequency range. Beam induced voltage has been measured with the ISIS beam, and compared with that calculated from the designed output impedance.