scholarly journals OPERATIONAL CHARACTERISTICS OF THE ELECTRON ACCELERATOR BASED ON THE PLASMA-FILLED DIODE

2021 ◽  
pp. 78-83
Author(s):  
E.I. Skibenko ◽  
A.N. Ozerov ◽  
I.V. Buravilov ◽  
V.B. Yuferov
Keyword(s):  
Plasma Density ◽  
Electron Accelerator ◽  
Plasma Parameters ◽  
Atomic Collisions ◽  
Elementary Processes ◽  
Neutral Gas ◽  
Operational Characteristics ◽  
Discharge Gap

The paper is concerned with the plasma-filled diode performance in the intensive mode regulated by means of external gas puffing. The possibility to smoothly vary the plasma parameters in the discharge gap zone, and thus, to optimize the main diode characteristics (Ucutoff, Icutoff) by the external gas puffing method has been confirmed by experiment. The introduction of additional quantity of neutral gas into the discharge causes the change in the plasma density balance due to elementary processes in physics of electronic and atomic collisions, such as ionization, dissociation, recombination. The deviation of actual voltage/current values from their maximum values can be attributed to the mismatch in the generator-load feed circuit.

scholarly journals Plasma parameters of microarcs towards minuscule discharge gap

2020 ◽  
Author(s):  
Margarita Baeva ◽  
Detlef Loffhagen ◽  
Markus M. Becker ◽  
Erwan Siewert ◽  
Dirk Uhrlandt
Keyword(s):  
Plasma Parameters ◽  
Discharge Gap

Isolated Sunspot with a Dark Patch in the Coronal Emission

2012 ◽  
Vol 21 (4) ◽  
Author(s):  
D. A. Bezrukov ◽  
B. I. Ryabov ◽  
K. Shibasaki
Keyword(s):  
Active Region ◽  
Normal Mode ◽  
Plasma Density ◽  
Specific Region ◽  
The Sun ◽  
Coronal Emission ◽  
Plasma Parameters ◽  
X Ray ◽  
Dark Patch ◽  
Chromospheric Line

AbstractOn the base of the 17 GHz radio maps of the Sun taken with the Nobeyama Radio Heliograph we estimate plasma parameters in the specific region of the sunspot atmosphere in the active region AR 11312. This region of the sunspot atmosphere is characterized by the depletion in coronal emission (soft X-ray and EUV lines) and the reduced absorption in the a chromospheric line (He I 1.083 μm). In the ordinary normal mode of 17 GHz emission the corresponding dark patch has the largest visibility near the central solar meridian. We infer that the reduced coronal plasma density of about ~ 5 × 10

Research on the Time and Space Characteristic of Argon Dielectric Barrier Discharge at Atmospheric Pressure

2014 ◽  
Vol 1008-1009 ◽  
pp. 630-634
Author(s):  
Zhi Nan Liu ◽  
Hui Min Ge
Keyword(s):  
Applied Voltage ◽  
Atmospheric Pressure ◽  
Fluid Model ◽  
Electrical Characteristics ◽  
Number Density ◽  
Plasma Parameters ◽  
One Dimensional ◽  
Space Characteristic ◽  
Discharge Gap ◽  
Bright Area

Numerical calculations with time dependant one-dimensional fluid model are performed at various conditions in argon atmospheric pressure to calculate electrical characteristics and plasma parameters including charged and metastable molecules densities. The simulation results show after steady discharge are formed, the voltage of discharge gap nearly remain constant and the phase is 0.36π advance of the applied voltage; The current density are in the same period as the applied voltage, the phase is 0.58π ahead of the applied voltage; The steady state Ar are in high number density in the whole discharge gap; The Ar* number density appear peak at the middle of the discharge gap; The Ar+ number density appear peak in the negative bright area.

scholarly journals Laser electron accelerator in plasma with adiabatically attenuating density

2007 ◽  
Vol 25 (2) ◽  
pp. 259-265 ◽  
Author(s):  
Y-J. SHI
Keyword(s):  
Phase Velocity ◽  
Plasma Density ◽  
Electron Accelerator ◽  
Energy Gain ◽  
Additional Energy ◽  
Trapped Electrons ◽  
Acceleration Mechanism ◽  
Relativistic Factor ◽  
Wake Instability ◽  
Driving Source

In this paper, we present a novel kind of electron acceleration mechanism when the trapped electrons are in a wake of plasma with adiabatically attenuating density. Accompanied with the increase of phase velocity βp of the wake owing to the plasma density attenuating adiabatically, the trapped electrons synchronized with the wake will get an additional acceleration besides the synchrotron oscillating acceleration just like in an accelerating elevator. The additional energy gain of the trapped electrons is determined by the value of the relativistic factor γpf = ω/ωp(zf) at the exit zf of the plasma wake. Moreover, the acceleration length is not limited by the dephasing deterministically any more, instead, it is mainly determined by the survivability of the wake. In other words, it is dependent upon the wake instability and its involving energy from driving source.

Simultaneous existence of stochastic and ohmic heating in capacitive discharges

2019 ◽  
Vol 85 (2) ◽  
Author(s):  
Khristo Tarnev ◽  
Rositsa Pavlova
Keyword(s):  
Ohmic Heating ◽  
Plasma Sheath ◽  
Plasma Parameters ◽  
One Dimensional ◽  
Particle In Cell ◽  
Simultaneous Existence ◽  
Capacitive Discharges ◽  
Large Discharge ◽  
Discharge Gap ◽  
Plasma Bulk

A one-dimensional particle-in-cell/Monte Carlo (PIC/MCC) model of low-pressure capacitive discharges with a large discharge gap is presented in the paper. The results from the model are for the dependence of the plasma parameters on the pressure and on the discharge radius. The study is directed to the heating mechanisms in the discharge. It is shown that the ohmic (Joule) heating in the plasma bulk could act simultaneously with the stochastic heating in the region of the plasma–sheath boundary. In confirmation of the results of the model, experimental results showing qualitatively the same behaviour are presented.

scholarly journals Ground-based observations of the auroral zone and polar cap ionospheric responses to dayside transient reconnection

2002 ◽  
Vol 20 (6) ◽  
pp. 781-794 ◽  
Author(s):  
J. A. Davies ◽  
T. K. Yeoman ◽  
I. J. Rae ◽  
S. E. Milan ◽  
M. Lester ◽  
...  
Keyword(s):  
Electron Density ◽  
Plasma Density ◽  
Closed Field ◽  
Polar Cap ◽  
Incoherent Scatter Radar ◽  
Plasma Parameters ◽  
Flux Transfer Events ◽  
Incoherent Scatter ◽  
Scatter Radar ◽  
Flux Transfer

Abstract. Observations from the EISCAT VHF incoherent scatter radar system in northern Norway, during a run of the common programme CP-4, reveal a series of poleward-propagating F-region electron density enhancements in the pre-noon sector on 23 November 1999. These plasma density features, which are observed under conditions of a strongly southward interplanetary magnetic field, exhibit a recurrence rate of under 10 min and appear to emanate from the vicinity of the open/closed field-line boundary from where they travel into the polar cap; this is suggestive of their being an ionospheric response to transient reconnection at the day-side magnetopause (flux transfer events). Simultaneous with the density structures detected by the VHF radar, poleward-moving radar auroral forms (PMRAFs) are observed by the Finland HF coherent scatter radar. It is thought that PM-RAFs, which are commonly observed near local noon by HF radars, are also related to flux transfer events, although the specific mechanism for the generation of the field-aligned irregularities within such features is not well understood. The HF observations suggest, that for much of their existence, the PMRAFs trace fossil signatures of transient reconnection rather than revealing the footprint of active reconnection itself; this is evidenced not least by the fact that the PMRAFs become narrower in spectral width as they evolve away from the region of more classical, broad cusp scatter in which they originate. Interpretation of the HF observations with reference to the plasma parameters diagnosed by the incoherent scatter radar suggests that as the PMRAFs migrate away from the reconnection site and across the polar cap, entrained in the ambient antisunward flow, the irregularities therein are generated by the presence of gradients in the electron density, with these gradients having been formed through structuring of the ionosphere in the cusp region in response to transient reconnection.Key words. Magnetospheric physics (magnetosphere-ionosphere interaction) – ionosphere (ionospheric irregularities; plasma density and temperature)

scholarly journals Parameters of a fast ion jet generated by an intense ultrashort laser pulse on an inhomogeneous plasma foil

2004 ◽  
Vol 22 (4) ◽  
pp. 431-438 ◽  
Author(s):  
A.A. ANDREEV ◽  
T. OKADA ◽  
K.Yu. PLATONOV ◽  
S. TORAYA
Keyword(s):  
Laser Pulse ◽  
Plasma Density ◽  
Laser Energy ◽  
Ion Beam ◽  
Inhomogeneous Plasma ◽  
Ion Acceleration ◽  
Plasma Parameters ◽  
Electrons And Ions ◽  
Foil Target ◽  
Fast Ion

Analysis and simulations of fast particles produced by a high-intensity short laser pulse interacting with a foil target are performed. Initially, the plasma density distribution of the foil target has a smooth gradient with the scale length of plasma density varying across it. The absorbed laser energy is transferred to fast electrons, which penetrate in the foil and are partially ejected from the foil rear. These electrons produce an electric field that causes an ion beam to be emitted from the foil. We analyze the mechanism of ion acceleration in the foil plasma and the influence of the density gradient and other laser and plasma parameters on ion acceleration. The angular distributions of the ejected electrons and ions are calculated.

Global Occurrence Rates of Ionospheric Plasma Density Irregularities Observed by Advanced Ionospheric Probe Onboard FORMOSAT-5 Satellite During Solar Minimum

2020 ◽  
Author(s):  
Yi-Wun Chen ◽  
Chi-Kuang Chao
Keyword(s):  
Plasma Density ◽  
Solar Minimum ◽  
Ionospheric Plasma ◽  
Sampling Rate ◽  
Science Data ◽  
Plasma Parameters ◽  
Ion Density ◽  
National Space ◽  
Space Organization ◽  
Ionospheric Plasma Density

<p>　　A remote sensing satellite, FORMOSAT-5, developed by National Space Organization (NSPO) carried a piggyback science payload, Advanced Ionospheric Payload (AIP), for space weather and seismo-ionospheric precursor study.  To meet the science requirements, AIP could be operated in different measurement modes to obtain various plasma parameters.  The first AIP measurement was performed on 7 September 2017 to obtain the first-orbit data and started routine operation in November the same year.  Global ion density and ion velocity/temperature distributions were available every two days and four days, respectively.  AIP was regularly operated in a sampling rate 1,024 Hz to maximize useful science data.  In this poster, global occurrence rates of pre-midnight low-latitude ionospheric plasma density irregularities will be shown from AIP science data collected since winter 2017.  The results indicate that seasonal variations of the occurrence rates during the solar minimum (2017/11-2019/12) are distributed very similar to but have lower magnitudes than those observations by ROCSAT-1/Ionospheric Plasma and Electrodynamics Instrument dataset (1999-2004) during solar maximum.</p>

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