IPAC2011 - List of Keywords (induction)

Paper	Title	Other Keywords	Page
TUPC143	New Techniques in the Synchronization of High-frequency Multichannel Acquisition Systems	instrumentation, neutron, controls, background	1359
	R.A.J. Soden, Y.A. Maumary, C. Zaretti Agilent Technologies SA, Plan-les-Ouates, Switzerland S.J. Narciso, J.L. Richard Agilent Technologies Inc., Loveland, USA
	Today, high-speed digitizer systems operating at well above 100 MSa/s are being used in a diverse range of applications including operation of single-pulse linear induction accelerators for flash radiographic facilities, neutron energy measurement through time-of-flight, and propulsion research. A growing number of such applications require simultaneous measurement of high-frequency signals over many channels. Most of today’s high-speed digitizers or oscilloscopes feature a maximum of only four channels. For applications requiring more than four channels, and needing very precise time correlation between channels or accurate phase of continuous signals, it is necessary to synchronize the sampling clocks of the multiple instruments within the system. This paper presents methods of synchronization, with reference to large-scale multichannel data acquisition requirements in particle acceleration applications using modular instrumentation. A range of system architectures are presented, and advantages and disadvantages of each scheme are discussed.

WEOAA02	Performance of 2 MeV, 2 kA, 200 ns Linear Induction Accelerator with Ultra Low Beam Emittance for X-Ray Flash Radiography	target, electron, focusing, cathode	1906
	P.V. Logachev, A. Akimov, P.A. Bak, M.A. Batazova, A.M. Batrakov, Y.M. Boimelshtain, D. Bolkhovityanov, A.A. Eliseev, F.A. Emanov, G.A. Fatkin, A.A. Korepanov, Ya.V. Kulenko, G.I. Kuznetsov, I.V. Nikolaev, A.V. Ottmar, A.A. Pachkov, A. Panov, O.A. Pavlov, D.A. Starostenko BINP SB RAS, Novosibirsk, Russia
	Funding: The minestry of education and science of Russian Federation R&D contracts:P2493 and 14.740.11.0160 LIA-2 linear induction accelerator is designed in Budker INP as an injector for full scale 20 MeV linear induction accelerator which can be used for X-ray flash radiography with high space resolution. This machine utilizes ultra high vacuum, precise beam optics design based on low temperature dispenser cathode of 190 mm in diameter. The results of LIA-2 commissioning are presented. The designed value of beam emittance (120 π mm•mrad, not normalized) is achieved at 2 MeV and 2 kA of electron beam energy and current.
	Slides WEOAA02 [7.094 MB]

WEOBA02	KEK Digital Accelerator and its Beam Commissioning	injection, ion, acceleration, kicker	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]

WEPC044	Minimizing Beam Motion in a Long-pulse Linear Induction Accelerator	target, injection, kicker, focusing	2109
	C. Ekdahl, E.O. Abeyta, J.B. Johnson, K. Nielsen, M.E. Schulze LANL, Los Alamos, New Mexico, USA T.P. Hughes, C.H. Thoma Voss Scientific, Albuquerque, New Mexico, USA C.-Y. Tom NSTec, Los Alamos, New Mexico, USA
	Funding: This work was supported by the US National Nuclear Security Agency and the US Department of Energy under contract DE-AC52-06NA25396. The Dual Axis Radiography for Hydrodynamic Testing (DARHT) Facility at Los Alamos uses two linear induction accelerators (LIAs) for flash radiography of explosively driven experiments from orthogonal viewpoints. The DARHT Axis-II long-pulse 1.8-kA, 16.5-MeV LIA is unique. It has a beam pulse with a 1600-ns flattop during which the kinetic energy varies < 2%. During this flattop, a kicker cleaves out four short micro-pulses, which are focused onto a high-Z target and converted to bremsstrahlung for multi-pulse flash radiography of the experiments. Asymmetric injection of the beam into the solenoidal focusing field, small temporal variations in accelerating potentials, and slight cell misalignments cause the beam position to wander during the flattop. This is undesirable for radiography, because it causes a displacement of the four radiographic source spots. Since the specific energy deposition from each micro-pulse can vaporize target material, succeeding pulses impact an asymmetric object causing a distortion of the source spot. This presentation will review the physics of the beam motion and the tuning procedures we have optimized to minimize the number of shots required.

WEPC115	A Global Optimization Approach Based on Symbolic Presentation of a Beam Propagator	controls, booster, focusing, quadrupole	2280
	S.N. Andrianov, A.N. Ivanov, M. Kosovtsov, E.A. Podzyvalov St. Petersburg State University, St. Petersburg, Russia
	It is known that modern systems of beam lines consist of huge control elements even in the case of small machines. The problem of the beam line design leads us to formulate this problem as a global optimization ones. This approach allows us defining a family of appropriate solutions. On the next steps a researcher should narrow this optimal solutions set using additional methods and concepts. The symbolic presentation of necessary information plays leading role on all steps of the suggested approach. The corresponding implementation presented in the paper allows us to find the optimal sets in parameters spaces in a proper way. The corresponding applied software was used for solution of some practical probems. The described ideology implies to use distributed and parallel technologies for necessary computing and will be integrated in the Virtual Accelerator concept.

WEPS075	Induction Sector Cyclotron for Cluster Ions	acceleration, ion, cyclotron, impedance	2679
	K. Takayama KEK, Ibaraki, Japan T. Adachi Sokendai, Ibaraki, Japan W. Jiang Nagaoka University of Technology, Nagaoka, Niigata, Japan H. Tsutsui SHI, Tokyo, Japan
	A novel scheme of a sector cyclotron to accelerate extremely heavy cluster ions, called Induction Sector Cyclotron (ISC), is described. Its key feature is fast induction acceleration. An ion bunch is accelerated and captured with pulse voltages generated by transformers. The acceleration and confinement in the longitudinal direction can be independently handled. Since the transformers are energized by the switching power supply, in which turning on/off of the switching gate is maneuvered by gate signals digitally manipulated from the circulating beam signal of an ion bunch, acceleration synchronizing with the revolution of ion beam is always guaranteed. A cluster ion beam such as C-60, which so far there has been no way to repeatedly accelerate, can be accelerated from extremely low energy to high energy. The fundamental concept of ISC is introduced and beam dynamical issues such as a life time of cluster ions under strong guide fields and repeatedly exerted pulse voltages in the existence of residual molecules are addressed. In addition, the present status of R&D works on a race track-shape induction accelerating cell will be presented. K.Takayama et al., submitted for publication (2011). ** K.Takayama and R.J.Briggs, Chapter 11 and 12 in Induction Accelerators (Springer, 2010).

WEPS081	The Study of Helium Ion FFAG Accelerator*	acceleration, ion, focusing, lattice	2697
	H.L. Luo, H. Hao, X.Q. Wang, H.L. Wu, Y.C. Xu USTC/NSRL, Hefei, Anhui, People's Republic of China
	As helium ion source, the periodic focusing structure model of Helium ion (He+) FFAG (Fixed-Field Alternating Gradient) accelerator was designed, providing He⁺ beam with higher beam current at a lower cost, which could be used for the study of the impact of Helium embitterment on fusion reactor envelope material. A radial sector scaling FFAG accelerator type with eight super-periods and a conventional magnetic lattice structure, a triplet focusing lattice-DFD combination, is adopted for He⁺ FFAG accelerator. In this paper, magnetic lattice is optimizing by analytical and numerical techniques. A large-aperture magnet is designed by using a 3D magnetic field simulation code OPERA-3D. Runge-Kutta tracking code used specifically for FFAG accelerator based on MATLAB language was used to track the particle in the magnetic field generated by OPERA-3D, followed by linear and nonlinear beam dynamics study. Some results of magnet design, particle tracking and dynamics study are presented in the article.

WEPZ004	Solid Pulse Transforming Line for DWA	impedance, coupling, simulation, high-voltage	2769
	L. Zhang CAEP/IFP, Mainyang, Sichuan, People's Republic of China
	This paper introduces the research work about solid pulse transforming line for dielectric wall accelerator(DWA). We will discuss the impedence of the solid pulse transforming line due to different material. Some research of PCSS(photoconductive semiconductor switch),which was used for DWA, will also be described.

THPC157	Hot-/Cold-Side Characterization of Asymmetric Undulator Magnets	undulator, permanent-magnet, magnet-design, insertion	3257
	F.-J. Börgermann Vacuumschmelze GmbH & Co. KG, Hanau, Germany S. Marks LBNL, Berkeley, California, USA
	The homogeneity of permanent magnets for use in undulators is dominantly described by small variations in remanence (±1%) and magnetic angles (±1°). The definition and measurement of the so-called hot-/cold-side-effect has proven to be useful as characterization of higher order variations of the local field components. It is measured by a Hall probe at a distance of the half gap width from both magnet pole-surfaces. Typical results for a batch of magnets lie in a range of about ±2% or less. For symmetrical permanent magnet geometries, the distribution is symmetric about the value of zero. In a batch of magnets for a new EPU at LBNL, however, we found an asymmetric distribution of the hot-/cold-side-effect. This asymmetry is attributed to the geometrically asymmetric cut-outs inside the magnets used for fixture on the aluminum keepers. We present a theoretical model which can predict this asymmetric influence on the hot-/cold-side-effect resulting from these small geometric asymmetries. The method may also be used to pre-calculate corrected specification values for the near-field results for future undulator magnets.

THPO027	Novel Switching Power Supply utilizing SiC-JFET and its Potential for the Digital Accelerator	power-supply, synchrotron, extraction, high-voltage	3400
	K. Okamura, T. Iwashita, K. Takayama, M. Wake KEK, Ibaraki, Japan K. Ise Tohoku Electric Power Co., Sendai, Japan Y. Osawa SUN-A Corporation, Miyoshi-City, Japan K. Takaki Iwate university, Morioka, Iwate, Japan
	Funding: Japan Science and Technology Agency New induction synchrotron system using an induction cell has been developed and constructed at KEK. We refer to the accelerator using the induction acceleration system combined with digitally controlled PWM power supply as "Digital Accelerator". In that system, the switching power supply is one of the key devices which realize digital acceleration. The requirements of the switching power supply are high voltage (2 kV) and high repetition frequency (1 MHz). In the present system, we used series connected MOSFETs as the switching device and obtained successful operation. However, series connection gives large complexity and less reliability. Among the various switching devices, a SiC-JFET is the promising candidates that substitute existing silicon MOSFET because it has ultrafast switching speed and voltage blocking capability. Therefore, we have started to develop new device in collaboration with device manufacturers. Switching and heat removal performance of the newly developed SiC-JFET and a future plan will be presented at the conference. T. Iwashita et al., “KEK Digital Accelerator”, Phys. Rev. ST-AB, published in 2011. ** K. Ise et al., IEEE Trans. Plasma Sci., pp. 730-736 (2011).

Paper

Title

Other Keywords

Page

TUPC143

New Techniques in the Synchronization of High-frequency Multichannel Acquisition Systems

instrumentation, neutron, controls, background

1359

R.A.J. Soden, Y.A. Maumary, C. Zaretti
Agilent Technologies SA, Plan-les-Ouates, Switzerland
S.J. Narciso, J.L. Richard
Agilent Technologies Inc., Loveland, USA

Today, high-speed digitizer systems operating at well above 100 MSa/s are being used in a diverse range of applications including operation of single-pulse linear induction accelerators for flash radiographic facilities, neutron energy measurement through time-of-flight, and propulsion research. A growing number of such applications require simultaneous measurement of high-frequency signals over many channels. Most of today’s high-speed digitizers or oscilloscopes feature a maximum of only four channels. For applications requiring more than four channels, and needing very precise time correlation between channels or accurate phase of continuous signals, it is necessary to synchronize the sampling clocks of the multiple instruments within the system. This paper presents methods of synchronization, with reference to large-scale multichannel data acquisition requirements in particle acceleration applications using modular instrumentation. A range of system architectures are presented, and advantages and disadvantages of each scheme are discussed.

WEOAA02

Performance of 2 MeV, 2 kA, 200 ns Linear Induction Accelerator with Ultra Low Beam Emittance for X-Ray Flash Radiography

target, electron, focusing, cathode

1906

P.V. Logachev, A. Akimov, P.A. Bak, M.A. Batazova, A.M. Batrakov, Y.M. Boimelshtain, D. Bolkhovityanov, A.A. Eliseev, F.A. Emanov, G.A. Fatkin, A.A. Korepanov, Ya.V. Kulenko, G.I. Kuznetsov, I.V. Nikolaev, A.V. Ottmar, A.A. Pachkov, A. Panov, O.A. Pavlov, D.A. Starostenko
BINP SB RAS, Novosibirsk, Russia

Funding: The minestry of education and science of Russian Federation R&D contracts:P2493 and 14.740.11.0160
LIA-2 linear induction accelerator is designed in Budker INP as an injector for full scale 20 MeV linear induction accelerator which can be used for X-ray flash radiography with high space resolution. This machine utilizes ultra high vacuum, precise beam optics design based on low temperature dispenser cathode of 190 mm in diameter. The results of LIA-2 commissioning are presented. The designed value of beam emittance (120 π mm•mrad, not normalized) is achieved at 2 MeV and 2 kA of electron beam energy and current.

Slides WEOAA02 [7.094 MB]

WEOBA02

KEK Digital Accelerator and its Beam Commissioning

injection, ion, acceleration, kicker

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]

WEPC044

Minimizing Beam Motion in a Long-pulse Linear Induction Accelerator

target, injection, kicker, focusing

2109

C. Ekdahl, E.O. Abeyta, J.B. Johnson, K. Nielsen, M.E. Schulze
LANL, Los Alamos, New Mexico, USA
T.P. Hughes, C.H. Thoma
Voss Scientific, Albuquerque, New Mexico, USA
C.-Y. Tom
NSTec, Los Alamos, New Mexico, USA

Funding: This work was supported by the US National Nuclear Security Agency and the US Department of Energy under contract DE-AC52-06NA25396.
The Dual Axis Radiography for Hydrodynamic Testing (DARHT) Facility at Los Alamos uses two linear induction accelerators (LIAs) for flash radiography of explosively driven experiments from orthogonal viewpoints. The DARHT Axis-II long-pulse 1.8-kA, 16.5-MeV LIA is unique. It has a beam pulse with a 1600-ns flattop during which the kinetic energy varies < 2%. During this flattop, a kicker cleaves out four short micro-pulses, which are focused onto a high-Z target and converted to bremsstrahlung for multi-pulse flash radiography of the experiments. Asymmetric injection of the beam into the solenoidal focusing field, small temporal variations in accelerating potentials, and slight cell misalignments cause the beam position to wander during the flattop. This is undesirable for radiography, because it causes a displacement of the four radiographic source spots. Since the specific energy deposition from each micro-pulse can vaporize target material, succeeding pulses impact an asymmetric object causing a distortion of the source spot. This presentation will review the physics of the beam motion and the tuning procedures we have optimized to minimize the number of shots required.

WEPC115

A Global Optimization Approach Based on Symbolic Presentation of a Beam Propagator

controls, booster, focusing, quadrupole

2280

S.N. Andrianov, A.N. Ivanov, M. Kosovtsov, E.A. Podzyvalov
St. Petersburg State University, St. Petersburg, Russia

It is known that modern systems of beam lines consist of huge control elements even in the case of small machines. The problem of the beam line design leads us to formulate this problem as a global optimization ones. This approach allows us defining a family of appropriate solutions. On the next steps a researcher should narrow this optimal solutions set using additional methods and concepts. The symbolic presentation of necessary information plays leading role on all steps of the suggested approach. The corresponding implementation presented in the paper allows us to find the optimal sets in parameters spaces in a proper way. The corresponding applied software was used for solution of some practical probems. The described ideology implies to use distributed and parallel technologies for necessary computing and will be integrated in the Virtual Accelerator concept.

WEPS075

Induction Sector Cyclotron for Cluster Ions

acceleration, ion, cyclotron, impedance

2679

K. Takayama
KEK, Ibaraki, Japan
T. Adachi
Sokendai, Ibaraki, Japan
W. Jiang
Nagaoka University of Technology, Nagaoka, Niigata, Japan
H. Tsutsui
SHI, Tokyo, Japan

A novel scheme of a sector cyclotron to accelerate extremely heavy cluster ions, called Induction Sector Cyclotron (ISC)*, is described. Its key feature is fast induction acceleration. An ion bunch is accelerated and captured with pulse voltages generated by transformers**. The acceleration and confinement in the longitudinal direction can be independently handled. Since the transformers are energized by the switching power supply, in which turning on/off of the switching gate is maneuvered by gate signals digitally manipulated from the circulating beam signal of an ion bunch, acceleration synchronizing with the revolution of ion beam is always guaranteed. A cluster ion beam such as C-60, which so far there has been no way to repeatedly accelerate, can be accelerated from extremely low energy to high energy. The fundamental concept of ISC is introduced and beam dynamical issues such as a life time of cluster ions under strong guide fields and repeatedly exerted pulse voltages in the existence of residual molecules are addressed. In addition, the present status of R&D works on a race track-shape induction accelerating cell will be presented.
* K.Takayama et al., submitted for publication (2011).
** K.Takayama and R.J.Briggs, Chapter 11 and 12 in Induction Accelerators (Springer, 2010).

WEPS081

The Study of Helium Ion FFAG Accelerator*

acceleration, ion, focusing, lattice

2697

H.L. Luo, H. Hao, X.Q. Wang, H.L. Wu, Y.C. Xu
USTC/NSRL, Hefei, Anhui, People's Republic of China

As helium ion source, the periodic focusing structure model of Helium ion (He+) FFAG (Fixed-Field Alternating Gradient) accelerator was designed, providing He⁺ beam with higher beam current at a lower cost, which could be used for the study of the impact of Helium embitterment on fusion reactor envelope material. A radial sector scaling FFAG accelerator type with eight super-periods and a conventional magnetic lattice structure, a triplet focusing lattice-DFD combination, is adopted for He⁺ FFAG accelerator. In this paper, magnetic lattice is optimizing by analytical and numerical techniques. A large-aperture magnet is designed by using a 3D magnetic field simulation code OPERA-3D. Runge-Kutta tracking code used specifically for FFAG accelerator based on MATLAB language was used to track the particle in the magnetic field generated by OPERA-3D, followed by linear and nonlinear beam dynamics study. Some results of magnet design, particle tracking and dynamics study are presented in the article.

WEPZ004

Solid Pulse Transforming Line for DWA

impedance, coupling, simulation, high-voltage

2769

L. Zhang
CAEP/IFP, Mainyang, Sichuan, People's Republic of China

This paper introduces the research work about solid pulse transforming line for dielectric wall accelerator(DWA). We will discuss the impedence of the solid pulse transforming line due to different material. Some research of PCSS(photoconductive semiconductor switch),which was used for DWA, will also be described.

THPC157

Hot-/Cold-Side Characterization of Asymmetric Undulator Magnets

undulator, permanent-magnet, magnet-design, insertion

3257

F.-J. Börgermann
Vacuumschmelze GmbH & Co. KG, Hanau, Germany
S. Marks
LBNL, Berkeley, California, USA

The homogeneity of permanent magnets for use in undulators is dominantly described by small variations in remanence (±1%) and magnetic angles (±1°). The definition and measurement of the so-called hot-/cold-side-effect has proven to be useful as characterization of higher order variations of the local field components. It is measured by a Hall probe at a distance of the half gap width from both magnet pole-surfaces. Typical results for a batch of magnets lie in a range of about ±2% or less. For symmetrical permanent magnet geometries, the distribution is symmetric about the value of zero. In a batch of magnets for a new EPU at LBNL, however, we found an asymmetric distribution of the hot-/cold-side-effect. This asymmetry is attributed to the geometrically asymmetric cut-outs inside the magnets used for fixture on the aluminum keepers. We present a theoretical model which can predict this asymmetric influence on the hot-/cold-side-effect resulting from these small geometric asymmetries. The method may also be used to pre-calculate corrected specification values for the near-field results for future undulator magnets.

THPO027

Novel Switching Power Supply utilizing SiC-JFET and its Potential for the Digital Accelerator

power-supply, synchrotron, extraction, high-voltage

3400

K. Okamura, T. Iwashita, K. Takayama, M. Wake
KEK, Ibaraki, Japan
K. Ise
Tohoku Electric Power Co., Sendai, Japan
Y. Osawa
SUN-A Corporation, Miyoshi-City, Japan
K. Takaki
Iwate university, Morioka, Iwate, Japan

Funding: Japan Science and Technology Agency
New induction synchrotron system using an induction cell has been developed and constructed at KEK*. We refer to the accelerator using the induction acceleration system combined with digitally controlled PWM power supply as "Digital Accelerator". In that system, the switching power supply is one of the key devices which realize digital acceleration. The requirements of the switching power supply are high voltage (2 kV) and high repetition frequency (1 MHz). In the present system, we used series connected MOSFETs as the switching device and obtained successful operation. However, series connection gives large complexity and less reliability. Among the various switching devices, a SiC-JFET is the promising candidates that substitute existing silicon MOSFET because it has ultrafast switching speed and voltage blocking capability**. Therefore, we have started to develop new device in collaboration with device manufacturers. Switching and heat removal performance of the newly developed SiC-JFET and a future plan will be presented at the conference.
* T. Iwashita et al., “KEK Digital Accelerator”, Phys. Rev. ST-AB, published in 2011.
** K. Ise et al., IEEE Trans. Plasma Sci., pp. 730-736 (2011).