928 research outputs found
The permittivity of a plasma at cyclotron resonance in large amplitude e.m. fields
The permittivity of a collisionless plasma as a function of field parameters is measured in standing and in travelling waves. In both experiments the permittivity remains finite at cyclotron resonance; the resonance is broadened and shifted towards higher values of the magnetic field strength. The results are in quantitative agreement with theoretical predictions which follow from a cold-plasma, large-signal analysis. The loss tangent of the plasma is measured. The loss is found to be due to the escape of accelerated particle
Physics of plasmachemistry
In the past few years, the physics of low temperature plasmas has received a new stimulus from applications in chemistry and surface treatment that have emerged empirically as extrapolations of hot gas-chemistry and e.g. chemical vapour deposition (CVD). The plasma chemistry field can be sub-divided into three classes: first, volume chemistry in which a gaseous feed is converted to other products by means of a discharge, as e.g. ozone-production in corona discharges in the air; second, surface modification where the surface of a substrate is altered by bombardment with atomic particles; third, melting and plasma spraying in which either material is melted by the heat of the plasma or surfaces are covered with particles of 10-100 mu m size accelerated and melted by the plasma. The author concentrates on surface modification which is, at present, the most extensively explored field. To a large extent the work is motivated by developments in submicron technology and the demand for thin high quality layers with anticorrosive, hardness or other propertie
The consistent solution of the undamped cyclotron-wave propagation problem
See abstr. A11563 of 196
Method of treating surfaces of substrates with the aid of a plasma and a reactor for carrying out the method
A method for treating substrate surfaces (e.g. etching and deposition) using a plasma. In practice the plasma flows from its source (13) to a treatment chamber (3). The plasma source is first flushed through with a flushing gas and when this has passed the cathodes (6), the reactant gas is fed into the plasma generator. The reactor used in this process is also described
Method of treating surfaces of substrates with the aid of a plasma
A method for treating substrate surfaces (e.g. etching and deposition) using a plasma. In practice the plasma flows from its source (13) to a treatment chamber (3). The plasma source is first flushed through with a flushing gas and when this has passed the cathodes (6), the reactant gas is fed into the plasma generator. The reactor used in this process is also described
Energy confinement of high-density tokamaks
Neoclassical ion heat conduction is the major energy loss mechanism in the center of an ohmically heated high-d. tokamak discharge (n>3 * 1020 m-3). This fixes the mutual dependence of plasma quantities on the axis and leads to scaling laws for the poloidal b and energy confinement time, given the empirical fact that the pressure profile and the c.d. profile are gaussian. [on SciFinder (R)
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