Time filter

Source Type

Losev V.,Institute of High Current Electronics
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2017

The results of multiterawatt laser beam formation of a visible range in THL-100 hybrid laser system based on titanium-sapphire front-end and photochemical XeF(C-A) boosting amplifier is presented. The front-end delivers up to 20 mJ energy in 50 fs pulses at the second harmonic centered around 475 nm. The active medium of the XeF(C-A) amplifier is produced in a XeF2/N2 mixture irradiated by the VUV radiation from electron beam excited xenon. The laser system is described and the latest results are presented. © 2017 SPIE.


News Article | February 21, 2017
Site: phys.org

Ionised matter, like plasma, still holds secrets. Physicists working with plasma jets, made of a stream of ionised matter, have just discovered a new phenomenon. Indeed, Eduard Sosnin from the Institute of High Current Electronics, Russian Academy of Sciences in Tomsk, Russia, and colleagues found a new type of discharge phenomenon in an atmospheric pressure plasma. It has been dubbed apokamp - from the Greek words for 'off' and 'bend', because it appears at a perpendicular angle to where plasma jets bend. Their findings have been recently published in EPJ D and are particularly relevant for the development of novel applications in medicine, health care and materials processing because they involve air at normal atmospheric pressure, which would make it cheaper than applications in inert gases or nitrogen. The authors established the conditions for the phenomenon to occur. It takes two electrodes positioned at an angle to each other, together with electric field lines which are curved upward between the two electrodes. It requires not one but both electrodes to have a high voltage to obtain an apokamp plasma jet, which typically develops from the bending point of the discharge channel. The apokamp can vary from a single needle to a 6-7-cm-long conical jet attached to the arc of the plasma current channel. Using high-speed photography data on the apokamp dynamics, the authors elucidated its nature as consisting of ionisation waves - so-called plasma bullets - that move with a velocity of 100-220 km/s. Such plasma bullets have previously been detected in inert gases and in nitrogen in the presence of negatively charged gas. The next step would require gathering sufficient data to build a model that can further explain the apokamp phenomenon. This phenomenon can help explain the blue jet phenomenon identified in 1994 in the upper atmosphere, where strange upwards-facing jets develop from thunderstorm clouds. More information: Eduard A. Sosnin et al, Dynamics of apokamp-type atmospheric pressure plasma jets, The European Physical Journal D (2017). DOI: 10.1140/epjd/e2016-70466-0


Kharlov A.V.,Institute of High Current Electronics
IEEE Transactions on Plasma Science | Year: 2010

Large capacitive energy storage systems are being implemented for powerful laser systems, electromagnetic launchers, and other pulsed power systems. Such megajoule-class modularized capacitor banks individually require precise reliable cost-effective robust closing switches for synchronous operation. The closing switch, under intense mechanical and thermal shocks imposed by a high peak current, must tolerate high charge transfer and provide long service life. The most popular closing switches up to date are spark gaps due to its relatively simple design, robustness, easy field maintenance, and repair. Spark gaps cover an impressive range of voltages, currents, Coulomb transfer, and repetition rates and an extremely wide range of applications. The main drawback of spark gaps is limited lifetime, which is related directly or indirectly to the erosion of the electrodes. The various types of switches have been introduced which utilize the principle of arc motion in a magnetic field thus effectively decreasing the current density on the switch electrodes. This paper presents the numerical calculations of arc motion and electrode erosion in a rail spark gap. The results of the numerical calculations are compared with the experimental results in this paper. The conditions for reduced electrode erosion are defined. © 2010 IEEE.


Tarasenko V.F.,Institute of High Current Electronics
Plasma Physics Reports | Year: 2011

Conditions under which the number of runaway electrons in atmospheric-pressure air reaches ~5 × 1010 are determined. Recommendations for creating runaway electron accelerators are given. Methods for measuring the parameters of a supershort avalanche electron beam and X-ray pulses from gas-filled diodes, as well as the discharge current and gap voltage, are described. A technique for determining the instant of runaway electron generation with respect to the voltage pulse is proposed. It is shown that the reduction in the gap voltage and the decrease in the beam current coincide in time. The mechanism of intense electron beam generation in gas-filled diodes is analyzed. It is confirmed experimentally that, in optimal regimes, the number of electrons generated in atmospheric-pressure air with energies T > eUm, where Um is the maximum gap voltage, is relatively small. © 2011 Pleiades Publishing, Ltd.


Korolev Y.D.,Institute of High Current Electronics
Gaodianya Jishu/High Voltage Engineering | Year: 2013

The paper reviews the results of investigations of the low-current atmospheric-pressure discharges in gas flow. The attention is focused on the discharges in electrode systems of coaxial plasmatron and of so-called gliding arc. It is demonstrated that a considerable fraction of discharge current is carried by a plasma column operating in a regime of normal glow discharge with occasional transitions to spark. The nature of glow-to-spark transition is discussed. Beside the plasma column, a weakly ionized gas fills in the interelectrode gap and forms a plasma jet at the exit of electrode system. The jet contains the active chemical particles that play important role in different discharge applications. The applications in plasma assisted combustion systems, for surface treatment with a usage of plasma jet, and for biology and medicine are considered.


Oreshkin V.I.,Institute of High Current Electronics
Physics of Plasmas | Year: 2013

The efficiency of conversion of the energy stored in the capacitor bank of a high-current pulse generator into the kinetic energy of an imploding plasma liner is analyzed. The analysis is performed by using a model consisting of LC circuit equations and equations of motion of a cylindrical shell. It is shown that efficient energy conversion can be attained only with a low-inductance generator. The mode of an "ideal" load is considered where the load current at the final stage of implosion is close to zero. The advantages of this mode are, first, high efficiency of energy conversion (80%) and, second, improved stability of the shell implosion. In addition, for inertial confinement fusion realized by the scheme of a Z pinch dynamic hohlraum, not one but several fusion targets can be placed in the cavity on the pinch axis due to the large length of the liner. © 2013 AIP Publishing LLC.


Oreshkin V.I.,Institute of High Current Electronics
Technical Physics Letters | Year: 2013

The efficiency of capacitor-bank energy transfer from a high-current pulse generator into kinetic energy of a plasma liner has been analyzed. The analysis was performed using a model including the circuit equations and equations of the cylindrical shell motion. High efficiency of the energy transfer into kinetic energy of the liner is shown to be achieved only by a low-inductance generator. We considered an "ideal" liner load in which the load current is close to zero in the final of the shell compression. This load provides a high (up to 80%) efficiency of energy transfer and higher stability when compressing the liner. © 2013 Pleiades Publishing, Ltd.


Loginov S.V.,Institute of High Current Electronics
Physics of Plasmas | Year: 2011

The paper considers the transport of a magnetic field in highly ionized plasma of microsecond megaampere plasma opening switches. Self-similar solutions for plasma aggregation by a linearly increasing magnetic field are derived. For these solutions, the magnetic field energy in the current channel is much lower than the energy of the accelerated plasma flow. The effect of Joule heating of the plasma becomes profound only with a uniform current density. It is shown that the evolution of the magnetic field in the accelerated flow is reduced to diffusion with an effective electrical conductivity proportional to the harmonic average of the Spitzer conductivity and conductivity dependent on the magnetic field in the current channel. Thus, during about the first 100 ns of the current pulse the conductivity of the current channel increases due to the plasma heating and, as the plasma is accelerated, its conductivity decreases. © 2011 American Institute of Physics.


Schneider A.,Institute of High Current Electronics
Proceedings - International Symposium on Discharges and Electrical Insulation in Vacuum, ISDEIV | Year: 2012

The present work is devoted to the estimation of anode temperature immediately after current zero following interruption of high current vacuum arc. Thermal radiation of a hot sample was registered using a 4-channels high-speed camera HSFC. Every camera channel was equipped with an interference filter to record radiation at various wavelengths (600, 700, 775, and 825 nm). First of all, calibrations of camera channels have been made. A molybdenum crucible with known spectral emissivity was used as a calibration sample. Experiments were carried out at different amplitudes of the arc current both with and without the axial magnetic field (AMF). © 2012 IEEE.


News Article | February 21, 2017
Site: www.eurekalert.org

Ionised matter, like plasma, still holds secrets. Physicists working with plasma jets, made of a stream of ionised matter, have just discovered a new phenomenon. Indeed, Eduard Sosnin from the Institute of High Current Electronics, Russian Academy of Sciences in Tomsk, Russia, and colleagues found a new type of discharge phenomenon in an atmospheric pressure plasma. It has been dubbed apokamp - from the Greek words for 'off' and 'bend', because it appears at a perpendicular angle to where plasma jets bend. Their findings have been recently published in EPJ D and are particularly relevant for the development of novel applications in medicine, health care and materials processing because they involve air at normal atmospheric pressure, which would make it cheaper than applications in inert gases or nitrogen. The authors established the conditions for the phenomenon to occur. It takes two electrodes positioned at an angle to each other, together with electric field lines which are curved upward between the two electrodes. It requires not one but both electrodes to have a high voltage to obtain an apokamp plasma jet, which typically develops from the bending point of the discharge channel. The apokamp can vary from a single needle to a 6-7-cm-long conical jet attached to the arc of the plasma current channel. Using high-speed photography data on the apokamp dynamics, the authors elucidated its nature as consisting of ionisation waves - so-called plasma bullets - that move with a velocity of 100-220 km/s. Such plasma bullets have previously been detected in inert gases and in nitrogen in the presence of negatively charged gas. The next step would require gathering sufficient data to build a model that can further explain the apokamp phenomenon. This phenomenon can help explain the blue jet phenomenon identified in 1994 in the upper atmosphere, where strange upwards-facing jets develop from thunderstorm clouds.

Loading Institute of High Current Electronics collaborators
Loading Institute of High Current Electronics collaborators