摘要:

AbstractThe evolution of resonant waves in closed turbulent plasma systems is considered. It is shown that the effect of the system's nonstationarity on the evolution of the resonant waves should be considered together with the nonlinear interactions of the same order. The case for which the plasma‐maser effect is significant in the presence of the nonstationarity is investigate

ISSN:0863-1042    

DOI:10.1002/ctpp.2150330102

出版商:WILEY‐VCH Verlag    

年代:1993

数据来源: WILEY

摘要:

AbstractThe electron energy distribution function was measured at the potential drops (double layer) formed between two negative Ar glows. The acceleration of the electrons by the electric field and the electron trapping due to the high plasma potential formed a double‐humped distribution functio

ISSN:0863-1042    

DOI:10.1002/ctpp.2150330103

出版商:WILEY‐VCH Verlag    

年代:1993

数据来源: WILEY

摘要:

AbstractWe made an attempt to study the propagation of multidimensional ion‐acoustic waves in multicomponent plasmas that include negative ions by deriving a Kodomtsev‐Petviashvili (K‐P) equation. The negative ions, as expected, introduce the precursor on the propagation because of which the need arises to derive a modified K‐P equation with higher order non‐linearity. We have examined a number of solitons like waves and supported the results by numerical simulation. The results reveal the existence of compressive and rarefactive solitary waves which are comparable with those of one‐dimensional solitary waves in plasmas with negative ions except that multidimensional propagation of ion‐acoustic waves is more involved than unidirectiona

ISSN:0863-1042    

DOI:10.1002/ctpp.2150330104

出版商:WILEY‐VCH Verlag    

年代:1993

数据来源: WILEY

摘要:

AbstractEnergy and particle balance of plasma in discharges with low density on JET is investigated. Self‐consistent transport analysis accounting bulk and edge plasma phenomena is carried out. It is shown that large difference between the ion edge temperature and the electron one could be the result of the influence of the secondary electron emission from the limiter in low density discharge

ISSN:0863-1042    

DOI:10.1002/ctpp.2150330105

出版商:WILEY‐VCH Verlag    

年代:1993

数据来源: WILEY

摘要:

AbstractA Monte Carlo code “1DHET” has been utilized for simulating the transport of neutral helium near divertor flat pumping target plate. The dominant atomic processes of electron impact ionization and elastic scattering by plasma ions are included. The thermal and streaming motion of the ions along the magnetic field is taken into consideration. Calculations show that the probability of neutral helium turning back to the target plate will increase by 45% if the divertor edge plasma density is smoothly raised up to 4.7 times higher at the divertor plate than that at 7cm apart inward as compared with the ordinary outward decreasing density profile while keeping temperature profile fixed. The temperature decreases smoothly from 40 eV at z = 7 cm to 3 eV at the plate. The effects of angle between the magnetic field and the target plate, the temperature of plate, edge plasma sheath potential and different target materials on the probability of helium particles scattered back to the plate are stud

ISSN:0863-1042    

DOI:10.1002/ctpp.2150330106

出版商:WILEY‐VCH Verlag    

年代:1993

数据来源: WILEY

摘要:

AbstractQuantitative optical spectroscopy measurements of the emission spectra of the N 2+(B2∑u,)ν′→X2∑gν″ transition (first negative system) in an Ar‐N2microwave discharge at atmospheric pressure have allowed determination of the rate coefficient of the production of N 2+molecules in theB2∑u, state with vibrational level ν′ = 0.The N 2+(B2∑u, ν′) molecules are produced by the reactionin a surface‐wave‐induced microwave discharge (2450 MHz) sustained in an open‐ended dielectric tube. The rate coefficientK ν′,ν″ν(T) has been obtained for ν′ν″ = 0 for different gas temperatures by varying the incident microwave power. TheK00(T) values are between 7.10−10and

ISSN:0863-1042    

DOI:10.1002/ctpp.2150330107

出版商:WILEY‐VCH Verlag    

年代:1993

数据来源: WILEY

ISSN:0863-1042    

DOI:10.1002/ctpp.2150330108

出版商:WILEY‐VCH Verlag    

年代:1993

数据来源: WILEY

摘要:

AbstractIn the paper we present the results of an investigation of a low frequency (30‐100 kHz) instability in a weakly magnetized discharge plasma. The instability is triggered by a disc electrode which terminates the magnetized plasma column and is biased above the plasma potential. Frequency dependence on various parameters, e.g. electrode diameter, electrode bias, neutral gas pressure and plasma density is measured. Space and time dependence of the plasma potential and density in the perturbed region during one period of the electrode current oscillation are measured. During the phase of the current decrease a potential structure moves in axial direction from the edge of the perturbed region towards the electrode. During the phase of current saturation the motion of ions is mostly radial. The observed phenomenon is approximately modeled as a two dimensional potential relaxation instability (PRI

ISSN:0863-1042    

DOI:10.1002/ctpp.2150330109

出版商:WILEY‐VCH Verlag    

年代:1993

数据来源: WILEY

ISSN:0863-1042    

DOI:10.1002/ctpp.2150330101

出版商:WILEY‐VCH Verlag    

年代:1993

数据来源: WILEY