Developments on Next-Generation Beam Handling of High-Energy Particles by using Non-linear Characteristics

Various developments had been conducted to produce a fast-response magnet by the traditional concepts based on the use of linear-characteristic elements, but the improvement is limited by the transmission theory. The application of non-linear phenomena is important to achieve further improvements. The recent progress and the future plan of the developments to produce a fast-response and strong field for high-energy particle handling are described here

Енергетичні характеристики наносекундного переривника струму вихідної ланки магнітно-напівпровідникового генератора імпульсів

Introduction. A semiconductor diode based on reverse current interruption is used to increase a pulse amplitude and peak power delivered on the process load. Usually, a current interrupter is located in the last stage of semiconductor-magnetic pulse generator (SMPG) and is connected in parallel to the load. Problem. Most of publications on this topic mostly concern with analysis of physical processes in the diode structure itself within its oscillating circuit, which is separated from previous SMPG’s pulse compression stages under condition of unidirectional energy transfer from the generator to the load. In this sense, the efficiency of conversion should be determined by the joint of electromagnetic interaction between non-linear compression stages, current interrupter and process load. Goal. Develop a mathematical model of nanosecond current interrupter to determine its electrical and energy characteristics as part of a high-voltage parallel circuit with magnetic pulse compression, depending on the duration and moment of current interruption, the equivalent circuit for load resistance, and to set the most optimal modes of its operation. Methodology. In this work, it is proposed to use a comprehensive approach aimed at the study of electromagnetic processes in the SMPG circuit with a nanosecond current interrupter, which takes into account the topology of circuit, the design parameters of switching reactor, the magnetization curve, the equivalent load resistance, as well as the time parameters of power switches. Results. Analytical expressions describing the electrical and energy characteristics of the interrupter when it operating on the active load are obtained. A numerical simulation of interrupter in the SMPG’s double-loop pumping circuit is carried out, taking into account a nonlinearity of SR’s magnetization curve. Three operation modes of interrupter is described, depending on the initial moment of reverse conduction current interruption. The analysis of interrupter operation on the load with an active-capacitive component is carried out. Practical meaning. The results of the research can be applied in the development of high-voltage SMPG scheme with improved energy-dynamic parameters.У даній роботі використовується комплексний підхід, спрямований на дослідження електромагнітних процесів у схемі магнітно-напівпровідникового генератора імпульсів з наносекундним переривником струму, який враховує топологію схеми, конструктивні параметри комутуючого дроселя, криву намагнічування його осердя, еквівалентний опір навантаження, а також часові параметри періодичної комутації силових ключів. Запропоновано модель наносекундного переривника струму паралельної ланки магнітного стиснення на основі експоненційного зростання його активного опору. Отримано аналітичні вирази, що описують електричні та енергетичні характеристики переривника струму при роботі на активне навантаження. Виконане числове модулювання переривника струму у двухконтурній схемі магнітного генератора імпульсів з урахуванням нелінійності кривої намагнічування комутуючих дроселів. Розглянуто три режими його роботи в залежності від моменту початку обриву струму зворотної провідності. Проведено аналіз роботи переривника струму на навантаження з активно-ємнісною складовою. Результати досліджень можуть бути застосовано при розробці високовольтних магнітно-напівпровідникових генераторів імпульсів з поліпшеними енергодинамічними параметрами

Conceptual Design of Rapid Circular Particle Accelerator Using High-Gradient Resonant Cavities with Fixed Frequency

A new high-energy particle accelerator with static combined type of magnetic field and high-gradient resonant cavities is introduced for muon acceleration up to 300 MeV and proton acceleration up to 400 MeV. The accelerator concept is expected to realize Mpps-class rapid cycling high-energy particle acceleration in circular particle accelerators. Conceptual designs of the circular accelerator are discussed with an emphasis on short lifetime particles. The fundamental concept of particle acceleration and the related practical issues, which should be discussed when designing the accelerators, are described as well

An Isolated High-Voltage High-Frequency Pulsed Power Converter for Plasma Generation

This thesis reviews plasma technology, pulsed power technology, basic structures of pulsed power generator and semiconductor devices. Based on above, an isolated high voltage pulsed power converter with high repetitive frequency for low power level application such as ozone generation is proposed in this thesis. The hardware for proposed pulsed power converter is well set up. The output pulsed voltage can reach -12 kV with pulse frequency up to 15 kHz. The pulse interval is designed as 1.6 μs. The proposed pulsed power converter system could be divided into two main parts, which are boost converter stage and a resonant stage. This thesis detailly introduces the structure and operating principles of the boost converter stage and the resonant stage. As for the boost converter stage, both analog control and digital control are applied to achieve the boost voltage function and power limiting function. As for the resonant stage, a pulse generating signal and spark protection function is achieved with a DSP control.This thesis also detailly gives an analysis for parasitic parameters of the proposed pulsed power converter system. Parasitic capacitances of SiC MOSFETs will affect spike performance of the proposed pulsed power converter system. A mathematical model of describing a relationship between parasitic capacitances of SiC MOSFETs and the spike voltage of the proposed pulsed power converter is proposed in this thesis. A comparison test is conducted to prove the proposed analysis.Master of Science in EngineeringElectrical Engineering, College of Engineering & Computer ScienceUniversity of Michigan-Dearbornhttps://deepblue.lib.umich.edu/bitstream/2027.42/143180/1/Master thesis_ Changqi You _format check_V3.pdfDescription of Master thesis_ Changqi You _format check_V3.pdf : Thesi

誘導性エネルギー蓄積に基づくパルスパワー発生に関する研究

国立大学法人長岡技術科学大

Development of High Power Square Wave Electroporators

High power microsecond and submicrosecond electric pulse generation and the devices for pulse generation (electroporators) development and application problem is focused in the dissertation. The electric field technologies, pulse forming circuits and circuit transient process compensation methods are investigated. The introduction presents the investigated problem, objects of research, importance of the dissertation, describes research methodology, scientific novelty and the defended statements. In the first chapter the scientific publications in the area of the high power electric pulses generation and application for biological cell permeabilization are overviewed. The influence of the pulse parameters on the biological effects is analysed. The requirements for the electroporators are identified. In the second chapter the prototypes of the high power square wave 5 μs – 10 ms up to 4 kV, 100 A and 200 ns – 5 μs up to 8 kV, 100 A electroporators are developed. The models for investigation of the transient processes in the circuits and the solutions for compensation are overviewed. The adequacy of the proposed models to the experimental results is analysed. The interdigitated microelectrodes structure for planar electroporation is proposed. The resultant electric field distribution and the cell medium temperature rise due to the Joule heating are investigated. The third chapter is focused on the experimental application of the developed high power microsecond and submicrosecond electroporators prototypes in biological experiments. The experimental results with different cell types are presented and conclusions are formed. Research results on the dissertation subject are published in 5 scientific articles: 3 articles – Thomson Reuters ISI Web of Science database journals with impact factor, 2 – publications referenced and abstracted in other international databases, 4 presentations have been made in international conferences in Lithuania, Netherlands, Germany and Japan

小型Marx発生器を用いた高繰り返しパルスパワー発生技

国立大学法人長岡技術科学大