Ya. E. Krasik
YOU?
Author Swipe
View article: Semi-cylindrical shock waves and blade-shaped supersonic jets generated by underwater electrical explosions of wire arrays
Semi-cylindrical shock waves and blade-shaped supersonic jets generated by underwater electrical explosions of wire arrays Open
We present the results of experimental studies and two-dimension hydrodynamic simulations of underwater electrical explosions of semi-cylindrical wire arrays. In the experiments, a pulse generator delivers a current pulse of ∼250 kA amplit…
View article: Water flows and phase transitions generated by strip line sub-microsecond time-scale discharges
Water flows and phase transitions generated by strip line sub-microsecond time-scale discharges Open
We present results of an experimental study of underwater strip line configurations with exploding or non-exploding foil electrodes, using a sub-microsecond generator delivering a ∼100 kA current pulse rising in 290 ns. For thin (≤15-μm) e…
View article: Time- and Space-Resolved Radiation from the Plasma Produced by High-Power, Sub-ns Microwave Pulse Gas Ionization
Time- and Space-Resolved Radiation from the Plasma Produced by High-Power, Sub-ns Microwave Pulse Gas Ionization Open
Time- and space-resolved radiation emitted by the plasma produced by a 0.8 ns duration at full width half maximum, ~600 MW maximum power microwave (~9.6 GHz) pulse traversing a hydrogen-, helium-, or air-filled circular waveguide, is studi…
View article: Studies of specific action integral and electro-thermal instabilities in the sub-microsecond underwater electrical explosions of shaped foils
Studies of specific action integral and electro-thermal instabilities in the sub-microsecond underwater electrical explosions of shaped foils Open
We present the results of two studies: (1) on the specific action integral h and (2) on the electrothermal instability (ETI) during underwater electrical explosions of different material foils. Values of h were studied in experiments with …
View article: An optimized design for an X-band high power relativistic diffraction output A8 magnetron
An optimized design for an X-band high power relativistic diffraction output A8 magnetron Open
Results of Particle in Cell simulations of an optimized design of a diffraction output relativistic A8 magnetron operating as a high power microwave (HPM) source in X-band (8.77 GHz) are presented. In addition to the very high efficiency o…
View article: The Brillouin flow in a smooth-bore magnetron fed by split cathode
The Brillouin flow in a smooth-bore magnetron fed by split cathode Open
Explosive emission from an axial cathode of a relativistic magnetron produces plasma, the radial expansion of which can cause pulse shortening. In a split cathode fed magnetron, the electron source and its explosive plasma are outside the …
View article: Helium and hydrogen gas ionization by a sub-nanosecond high-power microwave pulse
Helium and hydrogen gas ionization by a sub-nanosecond high-power microwave pulse Open
This study investigates the plasma formed by a ∼300 MW, ∼0.8 ns, ∼9.6 GHz high-power microwave (HPM) pulse propagating inside a waveguide filled by helium or hydrogen gas at different pressures. It was found that HPM traverses He and H2 ga…
View article: Electrothermal instabilities observed by x-ray radiography of underwater sub-microsecond electrical explosions of aluminum, silver, and molybdenum wires
Electrothermal instabilities observed by x-ray radiography of underwater sub-microsecond electrical explosions of aluminum, silver, and molybdenum wires Open
We present measurements of the wavelength of electrothermal instabilities (ETI) formed during underwater electrical explosions of aluminum (Al), silver (Ag), and molybdenum (Mo) wires. Wires were exploded using a ∼450 ns rise time and ∼120…
View article: The Brillouin flow in a smooth-bore magnetron fed by split cathode
The Brillouin flow in a smooth-bore magnetron fed by split cathode Open
Explosive emission from an axial cathode of a relativistic magnetron produces plasma, the radial expansion of which can cause pulse shortening. In a split cathode fed magnetron, the electron source and its explosive plasma are outside the …
View article: Acceleration of a dielectric flyer by underwater electrical explosions of a metallic foil or by the generated shockwave and waterflow
Acceleration of a dielectric flyer by underwater electrical explosions of a metallic foil or by the generated shockwave and waterflow Open
The results of experiments and numerical modeling show that a polyoxymethylene (Delrin) flyer is accelerated to nearly the same velocity (∼800 m/s) by either the underwater electrical sub-μs timescale explosion of 15 μm thick Al and Cu foi…
View article: Evolution of the electron distribution function during gas ionization by a sub-nanosecond microwave pulse of hundreds MW power
Evolution of the electron distribution function during gas ionization by a sub-nanosecond microwave pulse of hundreds MW power Open
The electron velocity distribution function in the plasma, formed by gas ionization by a microwave pulse of sub-nanosecond timescale width and hundreds of megawatts power, is studied by a theoretical model and by 3D numerical simulations w…
View article: Characterization of the Plasma Generated by a Compact Theta Pinch
Characterization of the Plasma Generated by a Compact Theta Pinch Open
Theta Pinch is one of the promising methods for the generation of hot and dense plasma. In this paper, we describe the results of experimental research on a small-scale Theta Pinch created with Helium or Hydrogen plasmas. Different plasma …
View article: Studies of gas ionization by high-power, sub-nanosecond microwave pulses
Studies of gas ionization by high-power, sub-nanosecond microwave pulses Open
This study investigates the ionization pressure threshold of a gas (air, helium, argon, and SF6 across a wide pressure range) filled dielectric tube when a ∼300 MW, ∼0.7 ns, 9.6 GHz high-power microwave (HPM) pulse propagates through it. T…
View article: Characterization of the Plasma Generated by a Compact Theta Pinch
Characterization of the Plasma Generated by a Compact Theta Pinch Open
Theta Pinch is one of the promising methods for the generation of hot and dense plasma. In this paper we describe the results of experimental research on a small-scale Theta Pinch creating with Helium or Hydrogen plasmas. Different plasma …
View article: Evolution of the electron distribution function during gas ionization by a sub-nanosecond microwave pulse of hundreds MW power
Evolution of the electron distribution function during gas ionization by a sub-nanosecond microwave pulse of hundreds MW power Open
The electron velocity distribution function in the plasma, formed by gas ionization with a sub-nanosecond, hundreds of megawatts power level microwave pulse, is studied by a theoretical model and by numerical 3D simulations, the results of…
View article: Studies of the specific current action integral in underwater electrical explosion of butterfly shaped foils
Studies of the specific current action integral in underwater electrical explosion of butterfly shaped foils Open
Results of experimental research and two-dimensional hydrodynamical simulations of close to critically damped microsecond timescale underwater electrical explosions of butterfly-shaped foils for six different materials are presented. Using…
View article: Electrical properties of different materials studied by sub-microsecond underwater electrical explosions of single wires
Electrical properties of different materials studied by sub-microsecond underwater electrical explosions of single wires Open
Results of an experimental research and one-dimensional hydrodynamical simulations of critically damped sub-microsecond timescale underwater electrical explosions of wires made of 12 different materials are presented. Using current and vol…
View article: Direct measurement of the wakefield excited by a high-power microwave pulse in plasma
Direct measurement of the wakefield excited by a high-power microwave pulse in plasma Open
An experimental method to measure the electric fields existing in a plasma wake produced by a ∼0.24 GW, ∼0.5 ns, 9.5 GHz microwave pulse traversing a plasma-filled waveguide is presented. The intensity of the second harmonic of a 30 fs 800…
View article: Revisiting the Luce diode in the context of recent research on multi-vircators with dielectric reflectors
Revisiting the Luce diode in the context of recent research on multi-vircators with dielectric reflectors Open
Recently, in a series of articles Mumtaz, Choi, and others [i.e., S. Mumtaz and E. Choi, IEEE Electronic Device Lett. 43, 1756 (2022)] studied a relativistic gridded vircator with one or more dielectric anodes, in which considerable increa…
View article: Multi frame radiography of supersonic water jets interacting with a foil target
Multi frame radiography of supersonic water jets interacting with a foil target Open
Pulsed-power-driven underwater electrical explosion of cylindrical or conical wire arrays produces supersonic water jets that emerge from a bath, propagating through the air above it. Interaction of these jets with solid targets may repres…
View article: Comparing magnetic pushing to underwater explosions for flyer acceleration
Comparing magnetic pushing to underwater explosions for flyer acceleration Open
We present results exploring various methods of aluminum flyer acceleration. One method uses the shock wave generated by underwater electrical explosions of thin foils supplied by a pulse generator with stored energy of ∼4.7 kJ. Utilizing …
View article: Underwater microsecond timescale electrical explosions of aluminum and copper foils
Underwater microsecond timescale electrical explosions of aluminum and copper foils Open
We present results on underwater electrical explosions of thin aluminum and copper foils using a generator delivering ∼200 kA current amplitude, ∼0.9 μs rise time pulses. Time-resolved shadow imaging displays the generation of a strong pla…
View article: Stationary striations in plasma, created by a short microwave pulse in a waveguide filled with a neutral gas
Stationary striations in plasma, created by a short microwave pulse in a waveguide filled with a neutral gas Open
It was observed experimentally that after crossing a waveguide filled with a neutral gas, a short powerful microwave pulse leaves a periodic glow of plasma along the waveguide, persisting several tens of nanoseconds. A theoretical model is…
View article: Characterizing the high-power-microwaves radiated by an axial output compact S-band A6 segmented magnetron fed by a split cathode and powered by a linear induction accelerator
Characterizing the high-power-microwaves radiated by an axial output compact S-band A6 segmented magnetron fed by a split cathode and powered by a linear induction accelerator Open
In a recent publication [J. Appl. Phys. 131, 023301 (2022)], microwave generation by a segmented A6 S-band axial output relativistic magnetron (RM) fed by a split cathode and powered by a small pulsed power generator was demonstrated for t…
View article: Synchrotron radiography of Richtmyer–Meshkov instability driven by exploding wire arrays
Synchrotron radiography of Richtmyer–Meshkov instability driven by exploding wire arrays Open
We present a new technique for the investigation of shock-driven hydrodynamic phenomena in gases, liquids, and solids in arbitrary geometries. The technique consists of a pulsed power-driven resistive wire array explosion in combination wi…
View article: Supersonic water jets as point-like sources of extremely high pressure
Supersonic water jets as point-like sources of extremely high pressure Open
Two interacting supersonic water jets and collisions of a water jet with an aluminum target are studied experimentally and by hydrodynamic simulations. Supersonic water jets form, when shocks generated by underwater electrical explosions o…
View article: Diocotron and electromagnetic modes in split-cathode fed relativistic smooth bore and six-vane magnetrons
Diocotron and electromagnetic modes in split-cathode fed relativistic smooth bore and six-vane magnetrons Open
In this article, the diocotron modes developing in a coaxial diode and the resonant magnetron modes forming in a six-vane A6 relativistic magnetron both fed by a split cathode are studied by Particle-in-Cell simulations. The split cathode …
View article: Addressing the critical parameters for overdamped underwater electrical explosion of wire
Addressing the critical parameters for overdamped underwater electrical explosion of wire Open
Experimental and magnetohydrodynamic numerical simulation results and analysis of a μs- and sub-μs-timescale overdamped underwater electrical explosion of copper wires having different lengths and diameters are presented. For these explosi…
View article: Observation of the diocotron instability in a diode with split cathode
Observation of the diocotron instability in a diode with split cathode Open
Diocotron instability has been observed in the pure electron plasma formed in a split cathode coaxial diode. This plasma consists of electrons, trapped in the longitudinal potential well between the two parts of the cathode. The mathematic…