IPAC2013 - List of Keywords (high-voltage)

Paper	Title	Other Keywords	Page
MOPEA064	A New Long Pulse High Voltage Extraction Power Supply for FETS	extraction, power-supply, ion-source, ion	228
	D.C. Faircloth, S.R. Lawrie, M. Perkins STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
	A new 25 kV 2 ms 50 Hz extraction voltage power supply has been developed for the high performance H-minus ion source for the Front End Test Stand at the Rutherford Appleton Laboratory. The power supply has been designed to fit in a single 19 inch rack and has a modular design for easy maintenance. This paper details the design and performance of the power supply and extracted beam currents.

MOPFI019	Beam Generation from a 500 kV DC Photoemission Electron Gun	gun, cathode, electron, laser	321
	N. Nishimori, R. Hajima, S.M. Matsuba, R. Nagai JAEA, Ibaraki-ken, Japan Y. Honda, T. Miyajima, M. Yamamoto KEK, Ibaraki, Japan H. Iijima, M. Kuriki HU/AdSM, Higashi-Hiroshima, Japan M. Kuwahara Nagoya University, Nagoya, Japan
	Funding: This work is supported by MEXT Quantum Beam Technology Program and partially supported by JSPS Grants-in-Aid for Scientific Research in Japan (23540353). The next generation light source such as X-ray FEL oscillator requires high brightness electron gun with megahertz repetition rate. We have developed a DC photoemission electron gun at JAEA for the compact energy recovery linac (cERL) light source under construction at KEK. This DC gun employs a segmented insulator with guard rings to protect the insulator from field emission generated from central stem electrode. We have successfully applied 500-kV on the ceramics with a cathode electrode in place and generated beam from the 500kV DC photoemission gun in October 2012. Details of the beam generation test will be presented.

MOPME025	Production of Extraction Kicker Magnet of the J-PARC 3-GeV RCS	kicker, vacuum, extraction, proton	526
	M. Kinsho, N. Ogiwara, K. Suganuma JAEA/J-PARC, Tokai-mura, Japan
	The J-PARC 3-GeV rapid cycling synchrotron (RCS) has been provided proton beam to the Material and Life Science Facility (MLF)as well as to the 50 GeV Main Ring (MR). Proton beam is accelerated from 181 MeV to 3GeV in the RCS and immediately extracted it to the beam transport line to the MLF and the MR. Extraction kicker magnets are used for this fast extraction. To improve reliability of the RCS for user operation, production of a reserve kicker magnet has been performed. The kicker magnet mainly consists of Ni-Zn ferrite cores and Aluminum alloy plates, and these parts are installed in vacuum chamber to prevent discharge because a high voltage is applied to the magnet for a short period. Since it is important to reduce the outgassing of water vapor form these parts to prevent discharge, we has been produced the reserve magnet with low outgassing at high voltage discharge. Since assemble of the kicker magnet already finished and vacuum test has been performed, the result of vacuum test is reported.

MOPME046	Preliminary Experimental Results of Axial B-dot Measuring Beam Tilt	coupling, simulation, dipole, impedance	577
	X. He, Q. Li, C. Ma, J. Pang, L. Zhao CAEP/IFP, Mainyang, Sichuan, People's Republic of China
	Funding: This work is under the support of NSFC project No. 11175166 Beam monitors sensitive to the beam's azimuthal B-dot field (sometimes referred as B-dots) are widly used to measure the displacement of beam centroid, as the beam generates a dipole term of the azimuthal magnetic field. The authors have pointd out that the similar B-dots sensitive to axial magnetic field can be used to measure the beam tilt directly in earlier work. A monitor which consists of four azimuthal B-dots and four axial B-dos is designed and fabricated. The monitor was tested on a coaxial calibration stand, which has a character resistance of 50 Ohm. Two position tuners are installed on the calibration stand, to adjust the position and the tilt of the inner conductor. Experiments show that the axial B-dot monitor can be successfully used to measure the tilt of the inner conductor directly.

MOPME057	Preliminary Operation of the Beam Loss Monitoring System at the 100-MeV Proton Linac	monitoring, linac, neutron	601
	S.P. Yun, Y.-S. Cho, J.-H. Jang, D.I. Kim, H.S. Kim, H.-J. Kwon, B.-S. Park, J.Y. Ryu, K.T. Seol, Y.-G. Song KAERI, Daejon, Republic of Korea
	A 100-MeV proton linac has been developed as the 1st phase of KOMAC (Korea Multi-purpose Accelerator Complex) under the project name of PEFP (Proton Engineering Frontier Project). The accelerator operation has to be carried out with the objective of limiting beam losses to less than 1 W/m. When the un-intended excessive beam loss occur, the BLM(Beam Loss Monitor) inform this beam loss to operator and transmit the signal to the MPS (Machine Protection System) for the rapid shut-off of the machine. The scintillation detector and proportional counter were selected as the BLM detector because of their fast response time and high sensitivity. At the beam commissioning stage, 20 BLMs will be prepared for the beam loss monitoring. This paper will report preliminary operation results of beam loss monitoring system. This work was supported by the Ministry of Education, Science and Technology of the Korean Government.

MOPWA003	New Development of Compact Fast Pulsed Power Supply System in the SPring-8	power-supply, kicker, radiation, pulsed-power	666
	C. Mitsuda, K. Fukami, K. Kobayashi, T. Nakanishi, H. Ohkuma, S. Sasaki JASRI/SPring-8, Hyogo-ken, Japan T. Ohshima RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
	We have developed a compact fast pulsed power supply system as a part of the development of the fast kicker magnet system in the SPring-8 storage ring. The kicker magnet is needed for the 1 ps short pulsed X-ray generation by a vertical kick and the suppression of the fast beam oscillation by counter kick. The required pulse width and current for above applications have to be a enough short time less than 4.8 us of the revolution time and more than 200 A respectively. We selected a Si-MOSFET as a switching device because a MOSFET has two capabilities of the fast switching and high-voltage resistance, and has a smaller size than an IGBT. The current are increased by parallel or parallel-series connecting of MOSFETs. We started the development of a test system whose output current was a 67 A with a pulse width of 1.0 us in 2008. From 2009 to 2011, we succeeded in achieving the output current of a 270 A with a pulse width of 0.8 us by using prototype system. In 2012, by increasing the number of MOSFET, we confirmed the output current of 250 A with a pulse width of 0.5 us, whose case size is a just 210(W) x 160(H) x 300(D) mm. We will report the development status in detail.

MOPWA007	Operating Experience of Kicker Magnet System in the J-PARC 3GeV RCS	kicker, synchrotron, extraction, neutron	678
	K. Suganuma, M. Kinsho, T. Togashi, M. Watanabe JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	The J-PARC 3-GeV rapid cycling synchrotron (RCS) has been provided proton beam to the Material and Life Science Facility (MLF)as well as to the 50 GeV Main Ring (MR). Proton beam is accelerated from 181 MeV to 3GeV in the RCS and immediately extracted it to the beam transport line to the MLF and the MR. Extraction kicker system is used for this fast extraction. The RCS has been operated for the neutron and MLF users program from December 23rd, 2008. At the beginning of user operation there were many troubles for the extraction kicker system, especially, thyratron which are used for switch of power supply often caused failure. The beam stop rate due to RCS extraction kicker system was more than 13% in the total beam stop of the J-PARC, establishment and operation experience of the tuning for power supply of the extraction kicker make the beam stop rate less than 0.5% in November 2012. In this paper, we are going to report about daily operation whose main is about operation of thyratron and the maintenance held in summer 2012. And　 We also going to report about the aptitude test of thyratron as a plan of the future.

MOPWA017	Design of the 500 kA Linear Transformer Driver Stage	simulation, pulsed-power, damping, induction	696
	T.X. Liang, X.F. Jiang, A.C. Qiu, F.J. Sun, Z.G. Wang, J.H. Yin, Z. Zhang NINT, Xi'an, People's Republic of China
	Funding: Supported by the funding of National Natural Science of China (Grant No. 51077111) and Stage Key Laboratory of Electrical Insulation and Power Equipment(Grant No.51077111) , Xi’an Jiaotong Univercity. Linear transformer driver (LTD) is a novel fast discharge high pulsed power source. It can realize many LTD stages in series or parallel conveniently, and can directly acquire 100~200ns high power pulse. The pulse maybe realizes to directly drive load without any pulse compressing and forming unit. This paper introduces the latest development of fast LTD technology in abroad. The 100kV/500kA LTD stage with the rise time of 150ns has been designed. The stage is consisting of 20 discharging bricks in parallel. The simplified circuit model of LTD stage is given and the output parameters are simulated with universal circuit simulation software program, and the matched load current of 500kA and the rise time of about 150ns is obtained at the charging voltage of the capacitors about ±80kV. Tianxue Liang is with the State Key Laboratory of Environment Simulation and Effect for Intense Pulsed Radiation, Northwest Institute of Nuclear Technology, P. O. Box 69-10, Xi’an 710024, China(phone:86-029-84767380; e-mail: liangtxlkk@163.com).

MOPWA018	CW-type HV Power Supply of 50 Hz and its Application in Accelerator Power Supply	electron, power-supply, impedance, damping	699
	Z.-F. He, D.M. Li, Y.H. Liu, S.L. Wang, J.-L. Zhang, Y.-T. Zhang SINAP, Shanghai, People's Republic of China
	Funding: The Knowledge Innovation Program of Chinese Academy of Sciences 　　The high-voltage power supply is an integral part of accelerator technology, as its stable and reliable output is an important guarantee for accelerator properly working. In a number of engineering practice of accelerator design and construction, we tried to use the Cockcroft-Walton (CW) type of power supply driven by 50 Hz and got success. It is of simple structure, low cost, easy maintenance, and high efficiency. This report describes the technical difficulties and the solutions in the CW-type power supply driven by 50 Hz. It also gives an introduction of the latest design of 800 kV/30 mA electron accelerator, which is being assembled at SINAP. Recent work has shown that it is an option to choose 50 Hz driven power system when it is more lenient on the voltage ripple but needed to be as high as possible on the energy conversion efficiency.

MOPWA021	Design of the Air Cooling System for the High Voltage Power Supply of a Electron Accelerator	power-supply, simulation, radiation, electron	705
	F. Zhong, X. Lei, J. Yang, L. Yang HUST, Wuhan, People's Republic of China
	High voltage electron accelerators are widely applied in many fields of radiation pro-cessing,and the high voltage power supply is the critical equipment for the accelerator. for the requirement of high voltage, the design of locate the power supply in a steel barrel filled with SF6 is commonly used. Considering the various losses of the power supply, an air-cooling system is needed. This paper presents the design of the air-cooling system for the high voltage power supply. The fluid simulation of SF6 based on Fluent and the optimal design of the air duct's structure and the thermal efficiency have been done. The comparison and analysis of the simulation and the empirical formula result is also carried out. It illustrates the design of the air-cooling system can satisfy the demand of the heat radiation This paper also provides an effective method for the optimal design of the air duct's structure and the maximize efficiency of heat exchange.

MOPWA022	A 500 kV Pulser with Fast Risetime for EMP Simulation	simulation, pulsed-power, impedance, laser	708
	W. Jia, W.Q. Chen, J.N. Li, J.P. Tang, L.S. Xie, Y.Z. Xie, G.W. Zhang NINT, Xi'an, People's Republic of China
	A fast risetime generator with 500kV rated output voltage for the electromagnetic pulse ( EMP ) effects experiment is fabricated. It mainly consists of a low inductance Marx ge nerator, a compact independent-sealed peaking capacitor, an output switch, and a small quantity of gas-sealed insulated containers. Compared with other similar pulsers mentioned in IEC 61000-4-32, the insulated containers of the generator are independent of each other in gas-sealed structure, and its number is les s than that of other pulsers. It can be used to drive a guided wave antenna directly to produce an electromagnetic environment, which conformed with the new standard for high-altitude nuclear explosion electromagnetic pulse (HEMP) developed by IEC. Output voltage produced by the generator in demo-load state can reach to 600kV. And, risetime of the waveform is 1.2ns, pulse width (FWHM) being 32ns. When the generator driving a 10m guided-wave antenna, an output voltage with a risetime of no more than 2.7ns and a FWHM of 30ns is achieved.

MOPWA023	A Low Jitter Pulse Generator Based on Two-stage Storage Module	pulsed-power, coupling, simulation, controls	711
	J.N. Li, W.Q. Chen, F. Guo, W. Jia NINT, Xi'an, People's Republic of China
	A scheme for a low jitter pulse generator based on two-stage storage module is described. The thyristor is used for the first stage of the generator, the UV-illumination gas switch is used for the second stage of the generator. Between them, the pulsed transformer is used for connecting. A capacitance-resistance coupling structure was designed to produce UV light which triggered the switch to decrease the breakdown jitter. The test result shows, the risetime of the current is 0.73μs, the peak value of the current is 1.8kA on 1.1Ω load. The delay of the generator is 35.1μs, and the jitter of the generator attaches to 0.22μs.

MOPWA042	The Leakage Current Induced by Stray Capacitance in the Pulse Magnet System	kicker, impedance, booster, injection	762
	C.S. Chen, C.K. Chan, K.H. Hsu, Y.-H. Liu, C.S. Yang NSRRC, Hsinchu, Taiwan
	A huge amount of current must be provided during the nominal operation of the pulse magnet system in TPS (Taiwan Photon Source). It comes with all kinds of electromagnetic noises, including radiated and conducted EMI (electromagnetic interferences). The primary object of this article is to clarify the paths of induced EMI, especially by means of capacitance induction. Furthermore, some geometrical suggestions which had been tested are listed in this paper as the guidelines of the pulse magnet design. According to the measurement, proper distance and surface area lead to sufficient insulation and reduce the leakage current under the expected value.

MOPWA065	Affordable, Short Pulse MARX Modulator	controls, shielding, linear-collider, collider	828
	R.A. Phillips, M.P.J. Gaudreau, M.K. Kempkes, B.E. Simpson Diversified Technologies, Inc., Bedford, Massachusetts, USA J.A. Casey Rockfield Research Inc., Las Vegas, Nevada, USA
	Under a U.S. Department of Energy grant, Diversified Technologies, Inc. (DTI) is developing a short pulse, solid-state Marx modulator for the next generation of klystrons and accelerators. For short-pulse modulators, this Marx topology provides a means to achieve astounding risetimes and flattop control that are simply not available with hard switch or transformer coupled topologies. The design is a high peak-power pulse modulator of greater efficiency than presently available, in the 100 kV to 1 MV range, for currents of 0.1 to 1 kA, pulse lengths of 0.2 to 5.0 us, and rise/fall times 10% of pulse length. A key objective of the development effort is a design which is modular and scalable, yet low cost, and easy to manufacture and maintain. The modulator will be delivered to Yale Beam Physics Laboratory for evaluation, and will be affordable for deployment at other national labs for klystron and modulator evaluation. In this paper, DTI will describe the new design and provide an update on progress.

MOPWA066	Components of Heating and Fueling of Fusion Plasmas	simulation, controls, cathode, synchrotron	831
	K. Schrock, M.P.J. Gaudreau, M.K. Kempkes Diversified Technologies, Inc., Bedford, Massachusetts, USA
	Funding: Funded by US DOE, Grant # DE-SC0004250 Next generation fusion facilities will require many megawatts of RF power from dozens of gyrotrons. Each gyrotron requires a power system that must deliver the high-voltage power, modulate cathode voltage, and protect these expensive gyrotrons from arcing damage. It must be highly efficient, to minimize both the power and cooling costs associated with operation and to ensure high facility availability. Diversified Technologies, Inc. (DTI) has bench-tested a table-top scale ‘Buck Matrix’ modulator which uses a single set of IGBT switches for voltage regulation, arc protection, and pulse modulation. Although pulse step modulators represent a one-step solution, their size, and the complexity of their driving transformer make them more expensive than DTI’s two-step approach. DTI’s Buck Matrix modulator, with an efficiency of ~96%, cuts the size of the system in half, using a single layer of solid state switches for both voltage regulation and arc protection/modulation. This cuts the total hardware costs by a~30% or more, and eliminates the need for a separate opening switch or crowbar. DTI will present the system components of the design as well as the performance results to date.

MOPWA074	High Voltage Converter Modulator Optimization	controls, neutron, feedback, background	852
	A. Scheinker LANL, Los Alamos, New Mexico, USA M.J. Bland University of Nottingham, Nottingham, United Kingdom
	High voltage converter modulators (HVCM) are at the forefront of long pulse high voltage (100kV) technology for Klystron voltage sources. We present results of digitally implementing an extremum seeking (ES) algorithm with which we optimized the rise time of the output voltage of a HVCM at the Los Alamos Neutron Science Center (LANSCE) HVCM test stand by iteratively, simultaneously tuning the first 8 switching edges of each of the three phase drive waveforms (24 variables total). We achieved a 50us rise time, which is reduction in half compared to the 100us currently achieved at the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory. The ES algorithm is successful despite the noisy measurements and cost calculations, confirming the theoretical predictions that the algorithm is not affected by noise unless it both matches exactly the frequency components of the controller's specific perturbing frequencies and is of comparable size.

WEIB205	Promoting Local Economic Development by an Integration of Industry, Teaching and Research of Compact Low Energy Accelerators	electron, radiation, permanent-magnet, HOM	2119
	M. Fan, D.Z. Chen, J. Huang, D. Li, K.F. Liu, B. Qin, Y.Q. Xiong, J. Yang, T. Yu HUST, Wuhan, People's Republic of China H.Q. Gao Hubei University of Science and Technology, Hubei, People's Republic of China
	Huazhong University of Science and Technology has been carrying out R&D of compact low energy accelerators by integrating industry, teaching and research to promote local economic development supported by both national and provincial government and local enterprises. Currently, the projects include: compact medical cyclotron, electron irradiation accelerators, etc. The industry of non-power nuclear energy based on low energy particle accelerator has also drawn attention from the provincial government of Hubei and municipal government of Xianning. Meanwhile, a series of lectures about nuclear science and nuclear safety were hosted to help the public better understand nuclear technology and to wipe out fears of nuclear energy. At the moment, the application of non-power nuclear energy with based on compact low energy accelerator is developing into an industry chain in the area of central China.
	Slides WEIB205 [2.311 MB]

WEPFI030	Design Studies on NSC KIPT Electron Gun System	gun, electron, cathode, power-supply	2768
	Z.S. Zhou, Y.L. Chi, D.Y. He IHEP, Beijing, People's Republic of China
	In NSC KIPT, a neutron source based on a subcritical assembly driven by a 100MeV/100kW electron linear accelerator is under design and development. The linear accelerator needs a new high current electron gun. In this paper, physical design, mechanical fabrication and beam test of this new electron gun are described. The emission current is designed to be higher than 2A for the pulse width of 3us with repetition rate of 50 Hz. The gun will operate with a DC high voltage power supply which can provide up to 150 kV high voltages. Computer simulations and optimizations have been carried out in the design stage, including the gun geometry and beam transport line. The test results of high voltage conditioning and beam test are presented. The operation status of the electron gun system is also included. The basic test results show that the design, manufacture and operation of the new electron system are basically successful.

WEPFI049	CoStub: A 6 1/8” Coaxial Short Circuit using Stubs	cavity, simulation, background, synchrotron	2809
	B. Bravo, F. Mares, F. Pérez CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain
	ALBA is a 3Gev synchrotron light source located in Barcelona and operating with users since May 2012. The ALBA storage ring uses six room temperature cavities; each one fed by two 80kW IOTs amplifiers at 499.654 MHz. The power of the pair of transmitters is combined by a cavity combiner, CaCo. The two possible operation modes of CaCo at high power have been tested. The symmetrical mode (two IOTs feed the CaCo symmetrically) works properly and without presenting any problem. But in the asymmetrical mode (one IOT feeds the CaCo and the other is keeping passive) a standing wave is created between the passive IOT and Caco, provoking a large voltage in the gap of the passive IOT that broke the ceramic. A new device, CoStub (coaxial stub), to short circuit the coaxial waveguide of the passive arm and protects the passive IOT has been built and successfully tested. This paper presents the design details and the low level and high power test of this device.

WEPFI078	LLNL X-band RF System	klystron, vacuum, gun, cathode	2875
	R.A. Marsh, G.G. Anderson, S.G. Anderson, C.P.J. Barty, S.E. Fisher, D.J. Gibson, F.V. Hartemann LLNL, Livermore, California, USA
	Funding: This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344 An X-band test station is being developed at LLNL to investigate accelerator optimization for future upgrades to mono-energetic gamma-ray technology at LLNL. The test station will consist of a 5.5 cell X-band rf photoinjector, single accelerator section, and beam diagnostics. The high power RF for the test station will be provided by a SLAC XL4 11.424 GHz klystron driven by a ScandiNova solid state modulator. The high power system has been installed and results of initial testing into high power loads will be presented. Performance of the system with respect to processing and stability will be discussed as well as future plans for the low level RF system.

THPEA021	A Platform Control System for 320 kV HV Platform	controls, power-supply, ion, LabView	3189
	W. Zhang, K. Gu, J.Y. Li, X.J. Liu IMP, Lanzhou, People's Republic of China
	This article describes the platform control system applied to the Chinese Academy of 320KV HV platform for highly charged ions. This system is composed of the hardware and the software. The hardware is composed of the network controller based on ATmega128 core chip. Our control group has designed the network controller for controlling the different types of equipment on the platform. The control system achieves the reliability, stability control of the different types of equipment on the HV platform, and control of the network, improve operational efficiency. The software uses NI Corporation's LABVIEW to program user interface. We have established for the application modules of the network controller in the LABVIEW and realized the optimization of the network controller to configure and use. The platform control system has run three years in the 320KV HV platform.

THPEA022	The Remote Control System for LAPECR1	controls, ion, ion-source, power-supply	3192
	W.X. Zhou, F.Y. Lin, J.F. Luo, Y.Y. Wang, J. Yin, Y.J. Yu, D.T. Zhou IMP, Lanzhou, People's Republic of China
	In order to support the debug of LAPECR1(Lanzhou All Permanent Magnet ECR Ion Source No.1) which merely provides H⁺ beam for HIRFL(Heavy Ion Research Facility in Lanzhou), a control system was realized in November 2011. The control system is composed of some controllers, a control-software and Intranet which is established by a switch. All of the controllers can access to Intranet directly or through serial-switch. And the controllers of the HV power and motor were designed by us. A IPC(Industrial Personal Computer) could control all of the equipments through Intranet. For the software of the system, it is designed using C++. And it could show the important data in the form of spectrum for the purpose of analysis and debug. The control system can acquire data and send command from/to the corresponding equipment.

THPFI067	The Mechanical Design, Fabrication, and Performance of the DCCT for TPS	vacuum, shielding, storage-ring, electron	3451
	C.-C. Chang, C.K. Chan, J.-R. Chen, G.-Y. Hsiung, H.P. Hsueh NSRRC, Hsinchu, Taiwan J.-R. Chen National Tsing Hua University, Hsinchu, Taiwan
	This paper describes the DC current transformers (DCCT), designed and fabricated for Taiwan Photon Source (TPS); including the mechanical structure, dissimilar material welding process for the DCCT chamber, electronically and vacuum performance testing. In the structure, a ceramic break disc is provided and jointed between to ends of the beam duct. The electrical connection path is interrupted in the beam duct adjacent to the transformer. To avoid the sensor measured the wall current and other unnecessary circulating currents. The DCCT toroid is independent installed outside of a vacuum beam duct to measure the average beam current. In order to reduce the influence of external magnetic field for the sensor, two layers of Mu metal shell are installed. The performance and progress for the DCCT are described in this paper.

THPWA022	An 800kV 30mA Line-Frequency Cockcroft-Walton Dc Generator Using Gas Insulated Transformer for Radiation Application	electron, power-supply, impedance, radiation	3675
	Y.H. Liu, H.L. Guo, Z.-F. He, D.M. Li, M.X. Li, W.G. Shi, H.J. Su, S.L. Wang, Y.J. Yang, J.L. Zhang, Y.-T. Zhang SINAP, Shanghai, People's Republic of China
	The design and construction of a line-frequency 800 kV Cockcroft-Walton DC generator using gas insulated transformers are described, as well as the motive to develop it into radiation application. Several features are underlined, preliminary test results of the prototype presented and some problems encountered discussed.

Paper

Title

Other Keywords

Page

MOPEA064

A New Long Pulse High Voltage Extraction Power Supply for FETS

extraction, power-supply, ion-source, ion

228

D.C. Faircloth, S.R. Lawrie, M. Perkins
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom

A new 25 kV 2 ms 50 Hz extraction voltage power supply has been developed for the high performance H-minus ion source for the Front End Test Stand at the Rutherford Appleton Laboratory. The power supply has been designed to fit in a single 19 inch rack and has a modular design for easy maintenance. This paper details the design and performance of the power supply and extracted beam currents.

MOPFI019

Beam Generation from a 500 kV DC Photoemission Electron Gun

gun, cathode, electron, laser

321

N. Nishimori, R. Hajima, S.M. Matsuba, R. Nagai
JAEA, Ibaraki-ken, Japan
Y. Honda, T. Miyajima, M. Yamamoto
KEK, Ibaraki, Japan
H. Iijima, M. Kuriki
HU/AdSM, Higashi-Hiroshima, Japan
M. Kuwahara
Nagoya University, Nagoya, Japan

Funding: This work is supported by MEXT Quantum Beam Technology Program and partially supported by JSPS Grants-in-Aid for Scientific Research in Japan (23540353).
The next generation light source such as X-ray FEL oscillator requires high brightness electron gun with megahertz repetition rate. We have developed a DC photoemission electron gun at JAEA for the compact energy recovery linac (cERL) light source under construction at KEK. This DC gun employs a segmented insulator with guard rings to protect the insulator from field emission generated from central stem electrode. We have successfully applied 500-kV on the ceramics with a cathode electrode in place and generated beam from the 500kV DC photoemission gun in October 2012. Details of the beam generation test will be presented.

MOPME025

Production of Extraction Kicker Magnet of the J-PARC 3-GeV RCS

kicker, vacuum, extraction, proton

526

M. Kinsho, N. Ogiwara, K. Suganuma
JAEA/J-PARC, Tokai-mura, Japan

The J-PARC 3-GeV rapid cycling synchrotron (RCS) has been provided proton beam to the Material and Life Science Facility (MLF)as well as to the 50 GeV Main Ring (MR). Proton beam is accelerated from 181 MeV to 3GeV in the RCS and immediately extracted it to the beam transport line to the MLF and the MR. Extraction kicker magnets are used for this fast extraction. To improve reliability of the RCS for user operation, production of a reserve kicker magnet has been performed. The kicker magnet mainly consists of Ni-Zn ferrite cores and Aluminum alloy plates, and these parts are installed in vacuum chamber to prevent discharge because a high voltage is applied to the magnet for a short period. Since it is important to reduce the outgassing of water vapor form these parts to prevent discharge, we has been produced the reserve magnet with low outgassing at high voltage discharge. Since assemble of the kicker magnet already finished and vacuum test has been performed, the result of vacuum test is reported.

MOPME046

Preliminary Experimental Results of Axial B-dot Measuring Beam Tilt

coupling, simulation, dipole, impedance

577

X. He, Q. Li, C. Ma, J. Pang, L. Zhao
CAEP/IFP, Mainyang, Sichuan, People's Republic of China

Funding: This work is under the support of NSFC project No. 11175166
Beam monitors sensitive to the beam's azimuthal B-dot field (sometimes referred as B-dots) are widly used to measure the displacement of beam centroid, as the beam generates a dipole term of the azimuthal magnetic field. The authors have pointd out that the similar B-dots sensitive to axial magnetic field can be used to measure the beam tilt directly in earlier work. A monitor which consists of four azimuthal B-dots and four axial B-dos is designed and fabricated. The monitor was tested on a coaxial calibration stand, which has a character resistance of 50 Ohm. Two position tuners are installed on the calibration stand, to adjust the position and the tilt of the inner conductor. Experiments show that the axial B-dot monitor can be successfully used to measure the tilt of the inner conductor directly.

MOPME057

Preliminary Operation of the Beam Loss Monitoring System at the 100-MeV Proton Linac

monitoring, linac, neutron

601

S.P. Yun, Y.-S. Cho, J.-H. Jang, D.I. Kim, H.S. Kim, H.-J. Kwon, B.-S. Park, J.Y. Ryu, K.T. Seol, Y.-G. Song
KAERI, Daejon, Republic of Korea

A 100-MeV proton linac has been developed as the 1st phase of KOMAC (Korea Multi-purpose Accelerator Complex) under the project name of PEFP (Proton Engineering Frontier Project). The accelerator operation has to be carried out with the objective of limiting beam losses to less than 1 W/m. When the un-intended excessive beam loss occur, the BLM(Beam Loss Monitor) inform this beam loss to operator and transmit the signal to the MPS (Machine Protection System) for the rapid shut-off of the machine. The scintillation detector and proportional counter were selected as the BLM detector because of their fast response time and high sensitivity. At the beam commissioning stage, 20 BLMs will be prepared for the beam loss monitoring. This paper will report preliminary operation results of beam loss monitoring system.
This work was supported by the Ministry of Education, Science and Technology of the Korean Government.

MOPWA003

New Development of Compact Fast Pulsed Power Supply System in the SPring-8

power-supply, kicker, radiation, pulsed-power

666

C. Mitsuda, K. Fukami, K. Kobayashi, T. Nakanishi, H. Ohkuma, S. Sasaki
JASRI/SPring-8, Hyogo-ken, Japan
T. Ohshima
RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan

We have developed a compact fast pulsed power supply system as a part of the development of the fast kicker magnet system in the SPring-8 storage ring. The kicker magnet is needed for the 1 ps short pulsed X-ray generation by a vertical kick and the suppression of the fast beam oscillation by counter kick. The required pulse width and current for above applications have to be a enough short time less than 4.8 us of the revolution time and more than 200 A respectively. We selected a Si-MOSFET as a switching device because a MOSFET has two capabilities of the fast switching and high-voltage resistance, and has a smaller size than an IGBT. The current are increased by parallel or parallel-series connecting of MOSFETs. We started the development of a test system whose output current was a 67 A with a pulse width of 1.0 us in 2008. From 2009 to 2011, we succeeded in achieving the output current of a 270 A with a pulse width of 0.8 us by using prototype system. In 2012, by increasing the number of MOSFET, we confirmed the output current of 250 A with a pulse width of 0.5 us, whose case size is a just 210(W) x 160(H) x 300(D) mm. We will report the development status in detail.

MOPWA007

Operating Experience of Kicker Magnet System in the J-PARC 3GeV RCS

kicker, synchrotron, extraction, neutron

678

K. Suganuma, M. Kinsho, T. Togashi, M. Watanabe
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

The J-PARC 3-GeV rapid cycling synchrotron (RCS) has been provided proton beam to the Material and Life Science Facility (MLF)as well as to the 50 GeV Main Ring (MR). Proton beam is accelerated from 181 MeV to 3GeV in the RCS and immediately extracted it to the beam transport line to the MLF and the MR. Extraction kicker system is used for this fast extraction. The RCS has been operated for the neutron and MLF users program from December 23rd, 2008. At the beginning of user operation there were many troubles for the extraction kicker system, especially, thyratron which are used for switch of power supply often caused failure. The beam stop rate due to RCS extraction kicker system was more than 13% in the total beam stop of the J-PARC, establishment and operation experience of the tuning for power supply of the extraction kicker make the beam stop rate less than 0.5% in November 2012. In this paper, we are going to report about daily operation whose main is about operation of thyratron and the maintenance held in summer 2012. And　 We also going to report about the aptitude test of thyratron as a plan of the future.

MOPWA017

Design of the 500 kA Linear Transformer Driver Stage

simulation, pulsed-power, damping, induction

696

T.X. Liang, X.F. Jiang, A.C. Qiu, F.J. Sun, Z.G. Wang, J.H. Yin, Z. Zhang
NINT, Xi'an, People's Republic of China

Funding: Supported by the funding of National Natural Science of China (Grant No. 51077111) and Stage Key Laboratory of Electrical Insulation and Power Equipment(Grant No.51077111) , Xi’an Jiaotong Univercity.
Linear transformer driver (LTD) is a novel fast discharge high pulsed power source. It can realize many LTD stages in series or parallel conveniently, and can directly acquire 100~200ns high power pulse. The pulse maybe realizes to directly drive load without any pulse compressing and forming unit. This paper introduces the latest development of fast LTD technology in abroad. The 100kV/500kA LTD stage with the rise time of 150ns has been designed. The stage is consisting of 20 discharging bricks in parallel. The simplified circuit model of LTD stage is given and the output parameters are simulated with universal circuit simulation software program, and the matched load current of 500kA and the rise time of about 150ns is obtained at the charging voltage of the capacitors about ±80kV.
Tianxue Liang is with the State Key Laboratory of Environment Simulation and Effect for Intense Pulsed Radiation, Northwest Institute of Nuclear Technology, P. O. Box 69-10, Xi’an 710024, China(phone:86-029-84767380; e-mail: liangtxlkk@163.com).

MOPWA018

CW-type HV Power Supply of 50 Hz and its Application in Accelerator Power Supply

electron, power-supply, impedance, damping

699

Z.-F. He, D.M. Li, Y.H. Liu, S.L. Wang, J.-L. Zhang, Y.-T. Zhang
SINAP, Shanghai, People's Republic of China

Funding: The Knowledge Innovation Program of Chinese Academy of Sciences
　　The high-voltage power supply is an integral part of accelerator technology, as its stable and reliable output is an important guarantee for accelerator properly working. In a number of engineering practice of accelerator design and construction, we tried to use the Cockcroft-Walton (CW) type of power supply driven by 50 Hz and got success. It is of simple structure, low cost, easy maintenance, and high efficiency. This report describes the technical difficulties and the solutions in the CW-type power supply driven by 50 Hz. It also gives an introduction of the latest design of 800 kV/30 mA electron accelerator, which is being assembled at SINAP. Recent work has shown that it is an option to choose 50 Hz driven power system when it is more lenient on the voltage ripple but needed to be as high as possible on the energy conversion efficiency.

MOPWA021

Design of the Air Cooling System for the High Voltage Power Supply of a Electron Accelerator

power-supply, simulation, radiation, electron

705

F. Zhong, X. Lei, J. Yang, L. Yang
HUST, Wuhan, People's Republic of China

High voltage electron accelerators are widely applied in many fields of radiation pro-cessing,and the high voltage power supply is the critical equipment for the accelerator. for the requirement of high voltage, the design of locate the power supply in a steel barrel filled with SF6 is commonly used. Considering the various losses of the power supply, an air-cooling system is needed. This paper presents the design of the air-cooling system for the high voltage power supply. The fluid simulation of SF6 based on Fluent and the optimal design of the air duct's structure and the thermal efficiency have been done. The comparison and analysis of the simulation and the empirical formula result is also carried out. It illustrates the design of the air-cooling system can satisfy the demand of the heat radiation This paper also provides an effective method for the optimal design of the air duct's structure and the maximize efficiency of heat exchange.

MOPWA022

A 500 kV Pulser with Fast Risetime for EMP Simulation

simulation, pulsed-power, impedance, laser

708

W. Jia, W.Q. Chen, J.N. Li, J.P. Tang, L.S. Xie, Y.Z. Xie, G.W. Zhang
NINT, Xi'an, People's Republic of China

A fast risetime generator with 500kV rated output voltage for the electromagnetic pulse ( EMP ) effects experiment is fabricated. It mainly consists of a low inductance Marx ge nerator, a compact independent-sealed peaking capacitor, an output switch, and a small quantity of gas-sealed insulated containers. Compared with other similar pulsers mentioned in IEC 61000-4-32, the insulated containers of the generator are independent of each other in gas-sealed structure, and its number is les s than that of other pulsers. It can be used to drive a guided wave antenna directly to produce an electromagnetic environment, which conformed with the new standard for high-altitude nuclear explosion electromagnetic pulse (HEMP) developed by IEC. Output voltage produced by the generator in demo-load state can reach to 600kV. And, risetime of the waveform is 1.2ns, pulse width (FWHM) being 32ns. When the generator driving a 10m guided-wave antenna, an output voltage with a risetime of no more than 2.7ns and a FWHM of 30ns is achieved.

MOPWA023

A Low Jitter Pulse Generator Based on Two-stage Storage Module

pulsed-power, coupling, simulation, controls

711

J.N. Li, W.Q. Chen, F. Guo, W. Jia
NINT, Xi'an, People's Republic of China

A scheme for a low jitter pulse generator based on two-stage storage module is described. The thyristor is used for the first stage of the generator, the UV-illumination gas switch is used for the second stage of the generator. Between them, the pulsed transformer is used for connecting. A capacitance-resistance coupling structure was designed to produce UV light which triggered the switch to decrease the breakdown jitter. The test result shows, the risetime of the current is 0.73μs, the peak value of the current is 1.8kA on 1.1Ω load. The delay of the generator is 35.1μs, and the jitter of the generator attaches to 0.22μs.

MOPWA042

The Leakage Current Induced by Stray Capacitance in the Pulse Magnet System

kicker, impedance, booster, injection

762

C.S. Chen, C.K. Chan, K.H. Hsu, Y.-H. Liu, C.S. Yang
NSRRC, Hsinchu, Taiwan

A huge amount of current must be provided during the nominal operation of the pulse magnet system in TPS (Taiwan Photon Source). It comes with all kinds of electromagnetic noises, including radiated and conducted EMI (electromagnetic interferences). The primary object of this article is to clarify the paths of induced EMI, especially by means of capacitance induction. Furthermore, some geometrical suggestions which had been tested are listed in this paper as the guidelines of the pulse magnet design. According to the measurement, proper distance and surface area lead to sufficient insulation and reduce the leakage current under the expected value.

MOPWA065

Affordable, Short Pulse MARX Modulator

controls, shielding, linear-collider, collider

828

R.A. Phillips, M.P.J. Gaudreau, M.K. Kempkes, B.E. Simpson
Diversified Technologies, Inc., Bedford, Massachusetts, USA
J.A. Casey
Rockfield Research Inc., Las Vegas, Nevada, USA

Under a U.S. Department of Energy grant, Diversified Technologies, Inc. (DTI) is developing a short pulse, solid-state Marx modulator for the next generation of klystrons and accelerators. For short-pulse modulators, this Marx topology provides a means to achieve astounding risetimes and flattop control that are simply not available with hard switch or transformer coupled topologies. The design is a high peak-power pulse modulator of greater efficiency than presently available, in the 100 kV to 1 MV range, for currents of 0.1 to 1 kA, pulse lengths of 0.2 to 5.0 us, and rise/fall times 10% of pulse length. A key objective of the development effort is a design which is modular and scalable, yet low cost, and easy to manufacture and maintain. The modulator will be delivered to Yale Beam Physics Laboratory for evaluation, and will be affordable for deployment at other national labs for klystron and modulator evaluation. In this paper, DTI will describe the new design and provide an update on progress.

MOPWA066

Components of Heating and Fueling of Fusion Plasmas

simulation, controls, cathode, synchrotron

831

K. Schrock, M.P.J. Gaudreau, M.K. Kempkes
Diversified Technologies, Inc., Bedford, Massachusetts, USA

Funding: Funded by US DOE, Grant # DE-SC0004250
Next generation fusion facilities will require many megawatts of RF power from dozens of gyrotrons. Each gyrotron requires a power system that must deliver the high-voltage power, modulate cathode voltage, and protect these expensive gyrotrons from arcing damage. It must be highly efficient, to minimize both the power and cooling costs associated with operation and to ensure high facility availability. Diversified Technologies, Inc. (DTI) has bench-tested a table-top scale ‘Buck Matrix’ modulator which uses a single set of IGBT switches for voltage regulation, arc protection, and pulse modulation. Although pulse step modulators represent a one-step solution, their size, and the complexity of their driving transformer make them more expensive than DTI’s two-step approach. DTI’s Buck Matrix modulator, with an efficiency of ~96%, cuts the size of the system in half, using a single layer of solid state switches for both voltage regulation and arc protection/modulation. This cuts the total hardware costs by a~30% or more, and eliminates the need for a separate opening switch or crowbar. DTI will present the system components of the design as well as the performance results to date.

MOPWA074

High Voltage Converter Modulator Optimization

controls, neutron, feedback, background

852

A. Scheinker
LANL, Los Alamos, New Mexico, USA
M.J. Bland
University of Nottingham, Nottingham, United Kingdom

High voltage converter modulators (HVCM) are at the forefront of long pulse high voltage (100kV) technology for Klystron voltage sources. We present results of digitally implementing an extremum seeking (ES) algorithm with which we optimized the rise time of the output voltage of a HVCM at the Los Alamos Neutron Science Center (LANSCE) HVCM test stand by iteratively, simultaneously tuning the first 8 switching edges of each of the three phase drive waveforms (24 variables total). We achieved a 50us rise time, which is reduction in half compared to the 100us currently achieved at the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory. The ES algorithm is successful despite the noisy measurements and cost calculations, confirming the theoretical predictions that the algorithm is not affected by noise unless it both matches exactly the frequency components of the controller's specific perturbing frequencies and is of comparable size.

WEIB205

Promoting Local Economic Development by an Integration of Industry, Teaching and Research of Compact Low Energy Accelerators

electron, radiation, permanent-magnet, HOM

2119

M. Fan, D.Z. Chen, J. Huang, D. Li, K.F. Liu, B. Qin, Y.Q. Xiong, J. Yang, T. Yu
HUST, Wuhan, People's Republic of China
H.Q. Gao
Hubei University of Science and Technology, Hubei, People's Republic of China

Huazhong University of Science and Technology has been carrying out R&D of compact low energy accelerators by integrating industry, teaching and research to promote local economic development supported by both national and provincial government and local enterprises. Currently, the projects include: compact medical cyclotron, electron irradiation accelerators, etc. The industry of non-power nuclear energy based on low energy particle accelerator has also drawn attention from the provincial government of Hubei and municipal government of Xianning. Meanwhile, a series of lectures about nuclear science and nuclear safety were hosted to help the public better understand nuclear technology and to wipe out fears of nuclear energy. At the moment, the application of non-power nuclear energy with based on compact low energy accelerator is developing into an industry chain in the area of central China.

Slides WEIB205 [2.311 MB]

WEPFI030

Design Studies on NSC KIPT Electron Gun System

gun, electron, cathode, power-supply

2768

Z.S. Zhou, Y.L. Chi, D.Y. He
IHEP, Beijing, People's Republic of China

In NSC KIPT, a neutron source based on a subcritical assembly driven by a 100MeV/100kW electron linear accelerator is under design and development. The linear accelerator needs a new high current electron gun. In this paper, physical design, mechanical fabrication and beam test of this new electron gun are described. The emission current is designed to be higher than 2A for the pulse width of 3us with repetition rate of 50 Hz. The gun will operate with a DC high voltage power supply which can provide up to 150 kV high voltages. Computer simulations and optimizations have been carried out in the design stage, including the gun geometry and beam transport line. The test results of high voltage conditioning and beam test are presented. The operation status of the electron gun system is also included. The basic test results show that the design, manufacture and operation of the new electron system are basically successful.

WEPFI049

CoStub: A 6 1/8” Coaxial Short Circuit using Stubs

cavity, simulation, background, synchrotron

2809

B. Bravo, F. Mares, F. Pérez
CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain

ALBA is a 3Gev synchrotron light source located in Barcelona and operating with users since May 2012. The ALBA storage ring uses six room temperature cavities; each one fed by two 80kW IOTs amplifiers at 499.654 MHz. The power of the pair of transmitters is combined by a cavity combiner, CaCo. The two possible operation modes of CaCo at high power have been tested. The symmetrical mode (two IOTs feed the CaCo symmetrically) works properly and without presenting any problem. But in the asymmetrical mode (one IOT feeds the CaCo and the other is keeping passive) a standing wave is created between the passive IOT and Caco, provoking a large voltage in the gap of the passive IOT that broke the ceramic. A new device, CoStub (coaxial stub), to short circuit the coaxial waveguide of the passive arm and protects the passive IOT has been built and successfully tested. This paper presents the design details and the low level and high power test of this device.

WEPFI078

LLNL X-band RF System

klystron, vacuum, gun, cathode

2875

R.A. Marsh, G.G. Anderson, S.G. Anderson, C.P.J. Barty, S.E. Fisher, D.J. Gibson, F.V. Hartemann
LLNL, Livermore, California, USA

Funding: This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344
An X-band test station is being developed at LLNL to investigate accelerator optimization for future upgrades to mono-energetic gamma-ray technology at LLNL. The test station will consist of a 5.5 cell X-band rf photoinjector, single accelerator section, and beam diagnostics. The high power RF for the test station will be provided by a SLAC XL4 11.424 GHz klystron driven by a ScandiNova solid state modulator. The high power system has been installed and results of initial testing into high power loads will be presented. Performance of the system with respect to processing and stability will be discussed as well as future plans for the low level RF system.

THPEA021

A Platform Control System for 320 kV HV Platform

controls, power-supply, ion, LabView

3189

W. Zhang, K. Gu, J.Y. Li, X.J. Liu
IMP, Lanzhou, People's Republic of China

This article describes the platform control system applied to the Chinese Academy of 320KV HV platform for highly charged ions. This system is composed of the hardware and the software. The hardware is composed of the network controller based on ATmega128 core chip. Our control group has designed the network controller for controlling the different types of equipment on the platform. The control system achieves the reliability, stability control of the different types of equipment on the HV platform, and control of the network, improve operational efficiency. The software uses NI Corporation's LABVIEW to program user interface. We have established for the application modules of the network controller in the LABVIEW and realized the optimization of the network controller to configure and use. The platform control system has run three years in the 320KV HV platform.

THPEA022

The Remote Control System for LAPECR1

controls, ion, ion-source, power-supply

3192

W.X. Zhou, F.Y. Lin, J.F. Luo, Y.Y. Wang, J. Yin, Y.J. Yu, D.T. Zhou
IMP, Lanzhou, People's Republic of China

In order to support the debug of LAPECR1(Lanzhou All Permanent Magnet ECR Ion Source No.1) which merely provides H⁺ beam for HIRFL(Heavy Ion Research Facility in Lanzhou), a control system was realized in November 2011. The control system is composed of some controllers, a control-software and Intranet which is established by a switch. All of the controllers can access to Intranet directly or through serial-switch. And the controllers of the HV power and motor were designed by us. A IPC(Industrial Personal Computer) could control all of the equipments through Intranet. For the software of the system, it is designed using C++. And it could show the important data in the form of spectrum for the purpose of analysis and debug. The control system can acquire data and send command from/to the corresponding equipment.

THPFI067

The Mechanical Design, Fabrication, and Performance of the DCCT for TPS

vacuum, shielding, storage-ring, electron

3451

C.-C. Chang, C.K. Chan, J.-R. Chen, G.-Y. Hsiung, H.P. Hsueh
NSRRC, Hsinchu, Taiwan
J.-R. Chen
National Tsing Hua University, Hsinchu, Taiwan

This paper describes the DC current transformers (DCCT), designed and fabricated for Taiwan Photon Source (TPS); including the mechanical structure, dissimilar material welding process for the DCCT chamber, electronically and vacuum performance testing. In the structure, a ceramic break disc is provided and jointed between to ends of the beam duct. The electrical connection path is interrupted in the beam duct adjacent to the transformer. To avoid the sensor measured the wall current and other unnecessary circulating currents. The DCCT toroid is independent installed outside of a vacuum beam duct to measure the average beam current. In order to reduce the influence of external magnetic field for the sensor, two layers of Mu metal shell are installed. The performance and progress for the DCCT are described in this paper.

THPWA022

An 800kV 30mA Line-Frequency Cockcroft-Walton Dc Generator Using Gas Insulated Transformer for Radiation Application

electron, power-supply, impedance, radiation

3675

Y.H. Liu, H.L. Guo, Z.-F. He, D.M. Li, M.X. Li, W.G. Shi, H.J. Su, S.L. Wang, Y.J. Yang, J.L. Zhang, Y.-T. Zhang
SINAP, Shanghai, People's Republic of China

The design and construction of a line-frequency 800 kV Cockcroft-Walton DC generator using gas insulated transformers are described, as well as the motive to develop it into radiation application. Several features are underlined, preliminary test results of the prototype presented and some problems encountered discussed.