A compact pulsed-power generator based on a linear-transformer-driver scheme has been developed and tested. It consists of ten modules using a total number of 350 power metal-oxide-semiconductor ...field-effect transistors as switches. It is capable of generating a peak output voltage of 9 kV and a peak output current of 175 A, with a pulselength of ~ 42 ns and a repetition rate of 1 kHz. The overall system efficiency is estimated to be ~ 59%.
Power semiconductor devices, such as insulated-gate bipolar transistors, metal-oxide-semiconductor field-effect transistors, and static-induction thyristors, are used in different kinds of pulsed ...power generators developed for different applications. In addition, the semiconductor opening switch is found to have very effective applications in pulsed power generation by inductive energy storage. Semiconductor switches have greatly extended the scales of pulsed power parameters, especially in repetition rate and lifetime. They have also enabled new areas of pulsed power applications, such as accelerators, flue-gas treatment, and gas lasers.
New SiC Kicker Power Supply for J-PARC Takayanagi, T.; Ono, A.; Sugita, M. ...
Journal of physics. Conference series,
01/2024, Letnik:
2687, Številka:
8
Journal Article
Recenzirano
Odprti dostop
Abstract
A new kicker power supply using silicon carbide metal–oxide semiconductor field-effect transistors (SiC-MOSFETs) is under development at the Japan Proton Accelerator Research Complex ...(J-PARC). SiC-MOSFETs fabricate compact high-speed pulse power supplies to replace the thyratron switch power supply. The base circuit of the new power supply uses the linear transformer driver (LTD) system, and the semi-conductor module circuit comprises a radial symmetry type that achieves low noise. The three main components of the current kicker power supply, i.e., the thyratron, pulse-forming network (PFN) circuit, and end clipper, can be assembled on a single board as the new module circuit board. The new power supply contains a 1.25 kV/2 kA main board that forms a trapezoidal pulse and a 0.1 kV/2 kA correction board, compensating for the flat section droop. The 32 main boards and 20 correction boards are hierarchically connected in series to achieve the waveform specifications required for the J-PARC rapid cycling synchrotron (RCS) kicker power supply: output voltage of 40 kV, output current of 2 kA, and pulse width of 1.2 μs. Furthermore, a 25 % power saving has been confirmed and an insulating cylinder for the conductor has been developed to suppress corona discharge and withstand continuous operation for a long time.
In this paper, we investigate a water treatment method that sprays waste water droplets into a pulsed discharge space. For this method, it is important to apply pulsed voltages with a short pulse ...width and a fast rise to the electrode to realize high energy efficiency. An inductive energy storage (IES) circuit using a semiconductor opening switch (SOS) outputs pulsed voltages similar to the above-mentioned voltage. We report the characteristics of the water treatment using the IES circuit. The capacitance and inductance in the IES circuit are varied. An increase in the inductance in the secondary circuit of the pulse transformer, results in the formation of pulsed voltages with a longer pulse width; thus, the ratio of the thermal loss to the discharge energy becomes high. However, the energy transfer efficiency improves. Additionally, we vary the maximum current of the SOS, keeping the pulse width constant, by adjusting the capacitance and the inductance. As a result, when the current in the SOS increased, pulsed voltages with a higher peak and a shaper rise are obtained. Further, the pulse width of the voltage and the energy transfer efficiency are not affected by the current in the SOS. Hence, the energy density of the discharge is higher. The increase in the secondary inductance and the forward current increased the energy efficiency of the water treatment system owing to the increase in the energy transfer efficiency and the discharge energy density.
Construction of rare-RI ring at RIKEN RI Beam Factory Yamaguchi, Y.; Wakasugi, M.; Uesaka, T. ...
Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms,
12/2013, Letnik:
317
Journal Article
Recenzirano
An isochronous mass spectroscopy system using a newly constructed storage ring named the “rare-RI ring” is expected to be implemented at the RIKEN Nishina Center to determine the masses of ...short-lived rare nuclei including those in the r-process region with a relative precision of the order of 10-6 even for only one particle. In an isochronous storage ring, the mass is determined by measuring the revolution time of each nucleus. Our rare-RI ring consists of six magnetic sectors, and each sector consists of four bending magnets. To precisely optimize the isochronous conditions of the circulating particles for large acceptance, we install ten trim coils to half of the bending magnets. A fast-response and fast-charging kicker system enables selective and efficient injection of the produced rare nuclei into the ring one by one, along with facilitating efficient extraction of the circulating particles for time-of-flight measurement. Construction of the rare-RI ring was begun in the middle of the fiscal year 2012 at the RIKEN RI Beam Factory, and the ring is expected to be fully functional by 2015.
Fast-kicker system for rare-RI ring Yamaguchi, Y; Miura, H; Wakasugi, M ...
Physica scripta,
11/2015, Letnik:
T166, Številka:
1
Journal Article
Recenzirano
We are developing a new fast-kicker system for rare-RI ring at RIKEN RI beam factory. New fast-kicker system enables us to inject a rare particle into the ring individually, and also to extract the ...rare particle from the ring quickly. It consists of a kicker power supply, which has a fast-response mechanism and a hybrid charging system, and a large acceptance kicker magnet. Propagation time from a trigger signal input to the power supply until the flat-top center of the kicker magnetic field is approximately 465 ns, the result is sufficient to achieve an individual injection with an energy of 200 MeV/nucleon. Reliable operation of the hybrid charging system makes it possible to extract a particle from the ring in 700 s by using the same kicker magnet. A waveform of the magnetic field is under investigation by using a prototype kicker magnet.
KEK digital accelerator Iwashita, T.; Adachi, T.; Takayama, K. ...
Physical review special topics. PRST-AB. Accelerators and beams,
07/2011, Letnik:
14, Številka:
7
Journal Article
Recenzirano
Odprti dostop
The High Energy Accelerator Research Organization KEK digital accelerator (KEK-DA) is a renovation of the KEK 500 MeV booster proton synchrotron, which was shut down in 2006. The existing 40 MeV ...drift tube linac and rf cavities have been replaced by an electron cyclotron resonance (ECR) ion source embedded in a 200 kV high-voltage terminal and induction acceleration cells, respectively. A DA is, in principle, capable of accelerating any species of ion in all possible charge states. The KEK-DA is characterized by specific accelerator components such as a permanent magnet X-band ECR ion source, a low-energy transport line, an electrostatic injection kicker, an extraction septum magnet operated in air, combined-function main magnets, and an induction acceleration system. The induction acceleration method, integrating modern pulse power technology and state-of-art digital control, is crucial for the rapid-cycle KEK-DA. The key issues of beam dynamics associated with low-energy injection of heavy ions are beam loss caused by electron capture and stripping as results of the interaction with residual gas molecules and the closed orbit distortion resulting from relatively high remanent fields in the bending magnets. Attractive applications of this accelerator in materials and biological sciences are discussed.
In order to investigate properties of warm dense matter (WDM) in inertial confinement fusion (ICF), evaluation method for the WDM with isochoric heating on the implosion time-scale using an intense ...pulsed power generator ETIGO-II (∼1 TW, ∼50 ns) has been considered. In this study, the history of input energy into the sample is measured from the voltage and the current waveforms. To achieve isochoric heating, a foamed aluminum with pore sizes 600 μm and with 90% porosity was packed into a hollow glass capillary (ø 5 mm × 10 mm). The temperature of the sample is calculated from the numerical calculation using the measured input power. According to the above measurements, the input energy into a sample and the achievable temperature are estimated to be 300 J and 6000 K. It indicates that the WDM state is generated using the proposed method with ICF implosion time-scale.
Pulsed Power Generation by Solid-State LTD Weihua Jiang; Sugiyama, Hiroka; Tokuchi, Akira
IEEE transactions on plasma science,
11/2014, Letnik:
42, Številka:
11
Journal Article
Recenzirano
A solid-state linear transformer driver stack has been developed to demonstrate pulsed power generation and output pulse shaping. It consists of 30 modules each using 24 power ...metal-oxide-semiconductor field-effect transistors as switches. The output voltage of the stack is the superposition of the voltage pulse of each module no matter if the modules are switched synchronously or not. In synchronous operation, the output voltages of all modules are added up to reach an output voltage up to ~29 kV with a maximum output current of ~240 A. The pulsewidth is variable in the range of 50-170 ns. On the other hand, by carrying out separate switching of different modules, the output waveform can be varied by performing pulse shaping. The control signals for pulse shaping experiment are generated using an field-programmable gate array board that allows potentially automatic waveform optimization.
"ETIGO-IV," a new repetitive pulsed-power generator, has been developed. It is capable of delivering, to a matched load, an output pulse of 400 kV in peak voltage, 13 kA in peak current, and 120 ns ...in pulse length, at the repetition rate of 1 Hz. It is aimed at applications to material development, pulsed ion-beam acceleration, and high-power microwave generation. This paper reports the design details and operation results of "ETIGO-IV," as well as the initial experimental results on electron beam generation.
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