Improved Regimes in High Pressure Magnetic Discharges

2010 ◽  
Author(s):  
Sergei V. Ryzhkov ◽  
Andrey V. Anikeev
Keyword(s):  
High Pressure ◽  
Energy Content ◽  
Radial Profile ◽  
High Energy ◽  
Plasma Pressure ◽  
Poloidal Magnetic Field ◽  
Gas Dynamic ◽  
Component Plasma ◽  
Field Lines ◽  
High Beta

Field-Reversed Configuration (FRC) [1] and Gas-Dynamic Trap (GDT) [2] represent compact system, which is a special magnetic geometry for plasma confinement. Theoretical and experimental study of gas-dynamic regimes with high energy content is carried out. The approach to a high beta (β is the ratio of plasma pressure to magnetic pressure) magnetic systems assumed different regimes of plasma with beta > 0.5 that is proper to compact devices such as tori and mirror traps. Both FRC and GDT traps are axial symmetric configurations, has open field lines and poloidal magnetic field only. Last experimental results on GDT have shown the possibility to build the stationary system with high beta. Analysis of the global energy and particle balance together with the Monte-Carlo equilibrium modelling allowed to conclude that two-component plasma confined in a steady-state regime. The characteristic plasma lifetimes are 4 to 5 times less then the experiment duration. A peripheral gas-puff near the mirror region enabled to maintain the radial profile of background plasma during the all neutral beam injection (NBI) pulse. This report is focused mainly on ambipolar effect and the possibility of further increasing the fast ion energy content and β. Improved gas-dynamic regimes in high pressure magnetic discharges and microinstabilities arising are described. Synthesized hot ion plasmoid (SHIP) experiment in the compact mirror section attached to the GDT central cell and the scheme of compact tori (FRC formation) for the compact mirror cell of GDT device are presented. Fusion prospects (reactor, neutron source, material studies) of such systems with high-energy (fast) particles [3, 4] and hybrid FRC + GDT scheme proposed by author from Bauman Moscow State Technical University (BMSTU) are discussed.

Kinetics of Fast Component and Energy Balance of the Plasma in Gas Dynamic System With Solenoidal Magnetic Field

2010 ◽  
Author(s):  
Alexei Chirkov ◽  
Sergey Kaskov
Keyword(s):  
Magnetic Field ◽  
Collision Operator ◽  
High Energy ◽  
Plasma Parameters ◽  
Magnetic Mirrors ◽  
Gas Dynamic ◽  
Barrier Formation ◽  
Maxwellian Plasma ◽  
Field Lines ◽  
Fast Ion

Numerical model of ion kinetics is considered for the axially symmetrical magnetic trap. Magnetic system of the trap consists of long solenoid and two end coils which constrict magnetic field lines and form so-called magnetic mirrors reflecting charged particles. The trap contains warm Maxwellian plasma and strongly non-Maxwellian high-energy (fast) ions. Steady-state fast ion population supported by the ionization of high-energy neutral atoms injected into the plasma. Physical model is based on the kinetic equation with two-dimensional Fokker–Planck collision operator in the velocity phase space. Regimes of plasma exhaust trough the mirrors are considered taking into account possibility of electrostatic barrier formation. Such regimes essentially differ from gas dynamic exhaust of the warm Maxwellian plasma. Parameters of power balance for the system under consideration are discussed.

scholarly journals Sustainment of High-Beta Mirror Plasma by Neutral Beams

2018 ◽  
Vol 5 (3) ◽  
pp. 125-127
Author(s):  
T. D. Akhmetov ◽  
V. I. Davydenko ◽  
A. A. Ivanov ◽  
S. V. Murakhtin
Keyword(s):  
Magnetic Field ◽  
Plasma Pressure ◽  
Budker Institute ◽  
Maximum Plasma ◽  
Axially Symmetric ◽  
Field Reversal ◽  
Neutral Beams ◽  
Gas Dynamic ◽  
High Beta ◽  
Fast Ion

The report presents two experiments carried out in Budker Institute for obtaining the maximum plasma beta (ratio of the plasma pressure to magnetic field pressure) in axially symmetric magnetic field. The experiments are based on injection of powerful focused neutral beams with high neutral power density in the plasma. The produced fast ion population significantly increases the plasma pressure. It the axially symmetric GDT experiment (Gas Dynamic Trap) the plasma beta exceeded 0.6 at the fast ion turning points. The CAT experiment (Compact Axisymmetric Toroid) is being prepared for obtaining a plasmoid with extremely high diamagnetism in axially symmetric magnetic field. Reversal of magnetic field in the plasmoid is possible in this experiment.

Nanostructured powders based on aluminum reinforced by silicon nitride designed for spraying of multifunctional strengthened coatings

2019 ◽  
pp. 65-73
Author(s):  
T. I. Bobkova ◽  
B. V. Farmakovsky ◽  
N. A. Sokolova
Keyword(s):  
Silicon Nitride ◽  
Composite Powder ◽  
High Energy ◽  
Cold Gas Dynamic Spraying ◽  
Powder Materials ◽  
Structure And Properties ◽  
Gas Dynamic ◽  
Composition Structure ◽  
New Phase ◽  
Nanostructured Powders

The work deals with topical issues such as development of composite nanostructured powder materials. The results of creating powders based on the system “aluminum–nitride of silicon” are presented. Complex investigations of the composition, structure and properties of powder materials, as well as coatings formed on their basis by supersonic cold gas dynamic spraying, were carried out. It has been found that the high-energy treatment of a powder mixture of aluminum with nanofibers of silicon nitride provides the formation of a composite powder in which a new phase of the Si(1-х)AlхO(1-х)Nх type is formed, which additionally increases the hardness in the coatings to be sprayed.

scholarly journals Spatiotemporal analysis of the runaway distribution function from synchrotron images in an ASDEX Upgrade disruption

2021 ◽  
Vol 87 (1) ◽  
Author(s):  
M. Hoppe ◽  
L. Hesslow ◽  
O. Embreus ◽  
L. Unnerfelt ◽  
G. Papp ◽  
...  
Keyword(s):  
Radial Profile ◽  
Spatiotemporal Analysis ◽  
High Energy ◽  
Synchrotron Emission ◽  
Analytic Model ◽  
Runaway Electrons ◽  
Radial Density ◽  
Radial Density Profile ◽  
Argon Injection ◽  
Seed Population

Synchrotron radiation images from runaway electrons (REs) in an ASDEX Upgrade discharge disrupted by argon injection are analysed using the synchrotron diagnostic tool Soft and coupled fluid-kinetic simulations. We show that the evolution of the runaway distribution is well described by an initial hot-tail seed population, which is accelerated to energies between 25–50 MeV during the current quench, together with an avalanche runaway tail which has an exponentially decreasing energy spectrum. We find that, although the avalanche component carries the vast majority of the current, it is the high-energy seed remnant that dominates synchrotron emission. With insights from the fluid-kinetic simulations, an analytic model for the evolution of the runaway seed component is developed and used to reconstruct the radial density profile of the RE beam. The analysis shows that the observed change of the synchrotron pattern from circular to crescent shape is caused by a rapid redistribution of the radial profile of the runaway density.

scholarly journals Penetration of MeV electrons into the mesosphere accompanying pulsating aurorae

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Y. Miyoshi ◽  
K. Hosokawa ◽  
S. Kurita ◽  
S.-I. Oyama ◽  
Y. Ogawa ◽  
...  
Keyword(s):  
High Energy ◽  
Daily Basis ◽  
Maximum Energy ◽  
Energy Electron ◽  
High Energy Electron ◽  
Whistler Mode ◽  
Chorus Waves ◽  
Mesospheric Ozone ◽  
Field Lines ◽  
Eiscat Radar

AbstractPulsating aurorae (PsA) are caused by the intermittent precipitations of magnetospheric electrons (energies of a few keV to a few tens of keV) through wave-particle interactions, thereby depositing most of their energy at altitudes ~ 100 km. However, the maximum energy of precipitated electrons and its impacts on the atmosphere are unknown. Herein, we report unique observations by the European Incoherent Scatter (EISCAT) radar showing electron precipitations ranging from a few hundred keV to a few MeV during a PsA associated with a weak geomagnetic storm. Simultaneously, the Arase spacecraft has observed intense whistler-mode chorus waves at the conjugate location along magnetic field lines. A computer simulation based on the EISCAT observations shows immediate catalytic ozone depletion at the mesospheric altitudes. Since PsA occurs frequently, often in daily basis, and extends its impact over large MLT areas, we anticipate that the PsA possesses a significant forcing to the mesospheric ozone chemistry in high latitudes through high energy electron precipitations. Therefore, the generation of PsA results in the depletion of mesospheric ozone through high-energy electron precipitations caused by whistler-mode chorus waves, which are similar to the well-known effect due to solar energetic protons triggered by solar flares.

scholarly journals Towards the Hydrogen Economy—A Review of the Parameters That Influence the Efficiency of Alkaline Water Electrolyzers

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3193
Author(s):  
Ana L. Santos ◽  
Maria-João Cebola ◽  
Diogo M. F. Santos
Keyword(s):  
Energy Content ◽  
Water Electrolysis ◽  
High Energy ◽  
Operating Conditions ◽  
Energy Sources ◽  
Alkaline Water Electrolysis ◽  
Alkaline Water ◽  
New Energy ◽  
Recent Developments ◽  
Cell Components

Environmental issues make the quest for better and cleaner energy sources a priority. Worldwide, researchers and companies are continuously working on this matter, taking one of two approaches: either finding new energy sources or improving the efficiency of existing ones. Hydrogen is a well-known energy carrier due to its high energy content, but a somewhat elusive one for being a gas with low molecular weight. This review examines the current electrolysis processes for obtaining hydrogen, with an emphasis on alkaline water electrolysis. This process is far from being new, but research shows that there is still plenty of room for improvement. The efficiency of an electrolyzer mainly relates to the overpotential and resistances in the cell. This work shows that the path to better electrolyzer efficiency is through the optimization of the cell components and operating conditions. Following a brief introduction to the thermodynamics and kinetics of water electrolysis, the most recent developments on several parameters (e.g., electrocatalysts, electrolyte composition, separator, interelectrode distance) are highlighted.

X‐ray determination of the Debye temperature at high pressure using high‐energy synchrotron radiation

1990 ◽  
Vol 68 (6) ◽  
pp. 2719-2722 ◽  
Author(s):  
A. Matsumuro ◽  
M. Kobayashi ◽  
T. Kikegawa ◽  
M. Senoo
Keyword(s):  
High Pressure ◽  
Synchrotron Radiation ◽  
Debye Temperature ◽  
High Energy ◽  
X Ray

Analysis of endurance of the material in the nozzle throat in high-pressure gas-dynamic facilities

2012 ◽  
Vol 53 (6) ◽  
pp. 954-960
Author(s):  
M. E. Topchiyan ◽  
V. I. Pinakov ◽  
A. A. Meshcheryakov ◽  
V. N. Rychkov
Keyword(s):  
High Pressure ◽  
Nozzle Throat ◽  
Gas Dynamic
Sign in / Sign up

Export Citation Format

Share Document