Confinement Of Charged Particles Research Articles

Linear model of confinement of charged particles in a quadrupole r.f. field in presence of buffer gases

We consider the trapping of particles in a harmonic well in presence of a diluted buffer gas. We established in a simple case a stochastic model which can be extended to the confinement in a qudrupole r.f. field.

Energy balance instability of a plasma in the thermonuclear reactor

The authors consider the energy balance stability of a thermonuclear plasma in a system where energy release is assumed to be due solely to fusion reactions and energy losses are assumed to be governed by bremsstrahlung and the thermal conductivity of the plasma. It is also assumed that the temperature at the plasma boundary is much lower than the temperature at which the thermonuclear reactions are initiated and that the energy lifetime of the plasma is short compared with the charged-particle confinement time.Expressions are obtained for the thermonuclear combustion stability criterion in respect of a fluctuation for which the temperature is either rising or falling at every point of the plasma. It follows from these expressions, in particular, that if the energy release is local and the coefficient of thermal conductivity is independent of the spatial derivatives of temperature, the energy balance of a deuterium-tritium plasma will be stable only when the temperature is greater than 30 keV.

Confinement of Charged Particles by Multiple-Mirror Systems

Monte Carlo techniques are used to evaluate particle confinement in mirror systems, including ones in which several mirrors are used in series. Predictions are compared with an experiment, and possible advantages of multiple-mirror systems with respect to plasma stability are described.

Confinement of charged particles in magnetic mirror systems

By means of the perturbation method, a complete set of integrals describing the motion of particles in an axially symmetric stationary electromagnetic field (magnetic field of mirror systems with an electric field), not restricted by the condition of adiabaticity, is derived. The integrals are used to derive the boundaries of particles' motion and to determine the regions of values of the integrals within which the particles are permanently trapped by the given magnetic system, regions within which the particles are trapped transiently (i.e. the particles execute a definite number of longitudinal oscillations between the mirrors and thereafter escape from the system), regions of particles traversing the system without being reflected and regions of particles which can be found only outside the system. A study of the resonance with cyclotron oscillations is also presented.

Loss Rates of Charged Particles from Ohmically-Heated Discharges in the C-Stellarator

Ionization rates in the C-Stellarator discharges of helium and hydrogen, with Ohmic heating, are deduced from measured electron densities, temperatures, and the intensities of certain spectrum lines. Particle loss rates are obtained from the difference between the ionization rates and the observed changes in electron densities. It is shown that the average charged particle confinement time varies linearly with the confining field and the aperture of the current channel and inversely with the electron temperature. The confinement time is the same for helium and hydrogen and is not explicitly dependent on ohmic heating current or particle density.

Effect of a strong magnetic field on the magnetohydrodynamic stability of a plasma and the confinement of charged particles in the 'tokamak' machine

Effect of a strong magnetic field on the magnetohydrodynamic stability of a plasma and the confinement of charged particles in the 'tokamak' machine

Effect of a strong magnetic field on the magnetohydrodynamic stability of a plasma and the confinement of charged particles in the `Tokamak' machine

Results are given of an experimental study of the plasma in the toroidal machine TM-2 in a strong axial magnetic field (up to 22 k oersted). It is shown that increasing the magnetic field strongly reduces the low-frequency fluctuations on oscillograms of the circuit voltage and discharge current derivative. It also weakens the interaction between the plasma and the wall of the discharge vessel.

Magnetic confinement of charged particles

The motion of charged particles in a cylindrical magnetic field is analysed by a perturbation-theoretic method in which the cylindrical field is treated as a perturbation of a uniform field, and is found to contain axial drift terms. These terms are evaluated to second order and used to formulate the conditions for a self-confining effect, such as would be required for plasma-containment in a thermonuclear reactor.

Loss of Charged Particles in a Stellarator During Ohmic Heating

The average charged particle confinement times τ0 in hydrogen and deuterium plasmas during Ohmic heating in the B-3 stellarator have been determined. The observed values of τ0 are approximately proportional to the square root of the magnetic confining field and were less than the values expected on the basis of classical collisional diffusion. The low values of τ0 persisted when the system was, in theory, made hydromagnetically stable by the addition of helical stabilizing winding. It is inferred that the observed low confinement times are not due to a known hydromagnetic instability.

Confinement of Charged Particles by Plane Electromagnetic Waves in Free Space

Confinement of Charged Particles by Plane Electromagnetic Waves in Free Space

On the confinement of charged particles in a magnetic field

A self-sustained thermonuclear fusion reaction requires a high degree of particle confinement. A ring-shaped solid conductor placed in the interior of the reaction volume produces a strong poloidal magnetic field which traps particles completely, at least at low gas densities. The leads which supply current to the conductor can be arranged in a way such as to prevent particle losses out of the confinement volume. Modifications and improvements of the magnetic field configuration by the addition of auxiliary coils are discussed.

Confinement of Charged Particles by a Magnetic Field

Confinement of charged particles by axially symmetrical, stationary magnetic fields and electric fields is discussed. It is shown that if the coil connections are made as small as possible and if the magnetic field, in the neighborhood of the connections, from the supply current predominates over the field from the coil, particles will be reflected and will not be absorbed by the connections. The field from the supply current gives an additional drift in planes through the z axis, but since the connections carry current in opposite radial directions, a cancellation of the drift takes place for particles passing around the z axis repeatedly. (J.S.R.)