IPAC2011 - List of Authors (Leo, K.W.)

Paper

Title

Page

Solid-state Marx Generator Driven Einzel Lens Chopper

1233

K. Takayama, T. Arai
KEK, Ibaraki, Japan
T. Adachi, K.W. Leo
Sokendai, Ibaraki, Japan
A. Tokuchi
Pulsed Power Japan Laboratory Ltd., Kusatsu-shi Shiga, Japan

A new type of pulse chopper called an Einzel lens chopper* is described. The Einzel lens, placed immediately after an electron cyclotron resonance ion source, is driven by high-voltage pulses generated by a newly developed solid-state Marx generator. A rectangular negative barrier pulse-voltage is controlled in time. The barrier pulse is switched on only when a beam pulse is required. When the barrier pulse is off, the DC voltage across the Einzel lens reflects ions back upstream with almost zero velocity. The device has been actually used as a chopper for the KEK Digital Accelerator, which is a small-scale induction synchrotron employing no a large injector and capable of providing a wide variety of ions, has been constructed at KEK**. A He ion beam of 50 micro-ampere was chopped in 5 micro-sec with rise/fall time of 40 nsec.
* T.Adachi et al., “A Solid-State Marx Generator Driven Einzel Lens Chopper”, submitted to Appl. Phys. Lett.
** T. Iwashita et al., “KEK Digital Accelerator”, Phys. Rev. ST-AB, published in 2011.

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]

Paper	Title	Page
TUPC096	Solid-state Marx Generator Driven Einzel Lens Chopper	1233
	K. Takayama, T. Arai KEK, Ibaraki, Japan T. Adachi, K.W. Leo Sokendai, Ibaraki, Japan A. Tokuchi Pulsed Power Japan Laboratory Ltd., Kusatsu-shi Shiga, Japan
	A new type of pulse chopper called an Einzel lens chopper* is described. The Einzel lens, placed immediately after an electron cyclotron resonance ion source, is driven by high-voltage pulses generated by a newly developed solid-state Marx generator. A rectangular negative barrier pulse-voltage is controlled in time. The barrier pulse is switched on only when a beam pulse is required. When the barrier pulse is off, the DC voltage across the Einzel lens reflects ions back upstream with almost zero velocity. The device has been actually used as a chopper for the KEK Digital Accelerator, which is a small-scale induction synchrotron employing no a large injector and capable of providing a wide variety of ions, has been constructed at KEK*. A He ion beam of 50 micro-ampere was chopped in 5 micro-sec with rise/fall time of 40 nsec. T.Adachi et al., “A Solid-State Marx Generator Driven Einzel Lens Chopper”, submitted to Appl. Phys. Lett. ** T. Iwashita et al., “KEK Digital Accelerator”, Phys. Rev. ST-AB, published in 2011.

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]