Eagle Harbor Technologies, Inc. (EHT) has developed a 35 kV pulser for driving 50 Ω loads with nanosecond-scale rise times. This inductive adder uses EHT’s nanosecond pulser technology to drive nonlinear transmission lines (NLTL) to construct an all-solid-state RF plasma heating system for fusion science applications. The inductive adder configuration allows for independently adjustable...
At present, the infrastructure of China Spallation Neutron Source (CSNS) project is finished in Dongguan city, Guangdong province of south China. Now the system debugging is under way. CSNS accelerator consists of an H- linac and a proton rapid cycling synchrotron. The 324MHz RF linac is designed with beam energy of 81MeV and a peak current of 30mA, which mainly includes one RF Quadrupole...
A prototype S-band sheet beam klystron has been fabricated and tested. To enable testing of this one of a kind tube, a unique test stand was created that we will discuss in this presentation. The sheet beam klystron was designed to operate at 2.856 GHz and nominally produce 6 MW peak / 6 kW average r.f. power. A ScandiNova solid state modulator delivers the high voltage pulse to the potted...
Abstract: The two-way power combiner consisting of two TM01-TE11 serpentine mode converters with a common output has demonstrated high power capacity and high combination efficiency for two phase-locked relativistic backward wave oscillators (RBWOs) [1]. To realize channel power combination for four phase-locked X-band RBWOs, we propose an all circular waveguide four-way power combiner based...
The coupling path of high power electromagnetic (HPEM) to electronic devices is divided into following two ways, one is the Front-door coupling and the other is the Back-door coupling1. The former is flow in an intended path such as antennas or sensors and the latter is inflow through an unintended path such as holes or cables. As HPEM pulse has higher power and it causes larger damage to...
K. Rainwater, D.H. Barnett, J. C. Dickens, A. Neuber and J. J. Mankowski Center for Pulsed Power and Power Electronics Dept. of Electrical and Computer Engineering Texas Tech University, Lubbock, TX, USA
This paper presents the electrical and mechanical hardware considerations of a compact, 160 J modular pulse forming...
A 400 kV - 85 ns PFN-Marx has been developed. Based on an innovative design [1], named the “zigzag design”, the 16 stages of this generator, which delivers an open circuit output voltage of 720 kV, fit in a 650 mm length. For a slightly overmatched load (Zload = 100 Ohm), the output voltage reaches 400 kV with a rise time as less as 5ns. The inductance reduction associated to the innovative...
Virtual cathode oscillator is a device that generates high power microwaves using oscillation of virtual cathode formed behind the anode. Virtual cathode oscillator has been studied due to its simple structure and tunability. Most virtual cathode oscillator system consists of prime power, pulsed power, microwave source, and antenna. In virtual cathode oscillator, pulsed power system produces...
**This paper presents experimental results from a repetitive pulse HPM-system, consisting of a marx-generator driving a coaxial vircator under high vacuum. The experiments were performed at starting vacuum levels in the high-vacuum range at pressure levels of safe operation for the system. Data was monitored of the vircator voltages and currents from the driving pulse generator, the vacuum...
In the report we present new approach where radiation phase of Ka-band BWO is controlled by an external rf signal which is ultra-short. Thus, such excitation is not an amplification regime. Particle-in-cell simulation demonstrated that phase-induced BWO excitation is feasible for a seed power minimized to -38 dB with respect to the driven BWO.
In experiments, two synchronized accelerators...
High power microwave sources play a significant role in a variety of applications such as accelerators, basic physics, astronomy, high power radar, thermonuclear fusion, and various industrial applications. The virtual cathode oscillator (vircator) is one of the most promising high-power microwave sources among several types of pulsed high power microwave generators. The vircator is considered...
Nonlinear Transmission lines (NLTLs) have been studied for high power RF generation with good prospects of applications in pulsed radar systems, disruption of communications in battlefield, etc. Usually, NLTLs employ barium titanate (BT) ceramic-based capacitors or ferrite bead inductor as nonlinear elements, denominated as capacitive or inductive lines, respectively. On the other hand, a...
Test stand complex for the testing of land and aerial based HPM sources is described. The stand utilizes low-inductance Marx generator operating in the repetitive burst regime with a rate 1-20 pulses/sec and total energy in pulse of 3kJ/pulse at 7Ohm load. Marx generator produces pulses with the risetime of 10-12 ns, output voltage and current 250-650 kV and 10-55 kA, respectively.
Marx...
High-power electromagnetic fields and currents in the excitation and propagation in the ground is of a significant interest for numerous applied problems. A pulsed electromagnetic field source has been developed for the related purposes. The source is designed as a dipole (vibrator) antenna, excited by the high-current pulsed discharges.
The usage of a dipole with a high input capacitance and...
Following impulse excitation of the primary winding of a Tesla transformer, the secondary response contains a fundamental component plus higher-order mode. The paper will describe a winding technique that enables the higher-order modes to be suppressed, and so provide a transformer output with an improved spectral purity, that is better suited for use in many high-power applications than...
A key parameter for the compressor operation is the switch performance, transferring from a storage (high Q) phase to release (low Q) phase. By initiation of plasma due to a gas discharge phenomenon it is possible to drastically change the boundary conditions and enable a fast phase transfer.
In this work, we investigate the use of a high peak power laser pulse to generate seed electrons and...
The majority of publications dealing with Tesla transformers are confined to studies of their performance based on a familiar lumped equivalent circuit. This paper will differ from these in being concerned with the very important and practical issue of the coupling between the two transformer winding. It will consider the importance of the coupling factor for different practical applications...
The Townsend breakdown theory is generally applicable in the case in which a DC voltage is applied to a gap filled with gases. The result of Townsend breakdown theory is generally not applicable directly in the case in which a high-power microwave propagates in the atmosphere. In this paper, we develop a theoretical model to describe the breakdown of high-power microwave propagation in the...
Application of microwave plasma offers a potential method to produce faster combustion in internal combustion engine1. In this paper, microwave multi-point ignition and spatial ignition had been confirmed via high-speed Schlieren imaging technique. The experiment was implemented with the microwave resonant ignition system and the Schlieren optical system. 2ms-3000W-2.45GHz plused microwave...
Vircator can generate GW class microwave power and is the preferred device in certain military application due to its simple structure and lighter weight because no magnet is used. Previous investigation [1] leads to the conclusion that applying a magnetic field on vircator is going to decrease its output power, to the extent eventually a total cutoff. However, previous study was conducted...
Periodic structures that reduce the velocity of electromagnetic wave propagation are widely used in electron beam driven high power microwave sources. When the frequency increases into the mm-wave region such structures become difficult to manufacture because of the small physical dimensions. “Additive Manufacturing” or “3D printing” offers the possibility of constructing certain types of...
Investigation of phase control in a klystron-like relativistic backward wave oscillator is presented in this paper. The guiding magnetic field, the distance between the input cavity and the pre-modulation cavity, the rise time of diode voltage, and the input signal frequency are optimized to decrease the phase jitter of output microwave. Particle-in-cell simulations show that when the diode...
The goal of this study is to design an Ultra-Wide Band (UWB) antenna for a High Power Microwaves (HPM) application. Classical antennas must be compatible with the bandwidth, the impedance of the system, and with the radiation characteristics (gain, directivity, and polarization). However, additional constraints such as high-voltage transient input signals have to be considered in the case of...
Sheet beam klystrons have many advantages over traditional round beam klystrons that are desirable for a variety of applications. They can operate at a high efficiency and relatively low voltage by keeping the perveance per unit area of the electron beam low. This is achieved by spreading the beam out in one dimension which decreases the current density and power density. They can produce...
Taiwan Photon Source (TPS) is an accelerator particle ring. This facility provides with a high luminance and stabilize source in which electron beam is produced form linac via a booster ring to storage ring for user studies. After electron beam is stored in the ring, its power would lose due to the energy dissipation. A RF Cavity (Nb,5 Cells) in Booster Ring is used to compensate the lose...
