C. A. Kapetanakos

Plasma heating by an intense relativistic electron beam

A 400‐keV 40‐kA 50‐nsec‐duration relativistic electron beam is injected into a plasma confined in a magnetic mirror. It is found that the coupling efficiency of beam energy into the plasma at fixed magnetic field is optimum when the beam and plasma densities are comparable, and is independent of magnetic field, provided it exceeds 2.5 kG.

Production of intense deuteron beams

Results are reported on the production of 400‐keV 50‐nsec‐duration 1.3‐kA deuteron beams using a reflex triode.

Transformation of the magnetic energy of a rotating relativistic beam into plasma energy

An intense rotating relativistic electron beam of energy 500 kV and current 40−50 kA is injected into neutral gas of pressure 200−700 mTorr, in the presence of an external magnetic field B0≃800 G. It is observed that the ratio of the magnetic field on axis ΔBz(r=0) to B0 is ΔBz(r=0)/B0≃2.2. The average magnetic energy density is about 2.5×1016 eV cm−3. Spectroscopic results show that most of this energy is transferred to the plasma through Joule heating.

Energy Deposition into Dense Collisionless Plasmas by Rotating Beams.

A nonturbulent mechanism is proposed whereby a rotating electron or ion beam pulse rapidly transfers energy to the ions of a dense, magnetized, weakly collisional plasma through excitation of the compressional Alfven mode. (auth)

Formation of field−reversing ion rings using microsecond ion pulses

Field−reversing ion rings may be formed using microsecond ion pulses. The short−circuit of the anode−cathode gap caused by the cathode plasma is delayed by placing the diode inside a nonsymmetric cusped magnetic field.

Rigid Rotor Equilibrium of a Strong Ion Layer.

The equilibrium properties of a strong, space charge neutral ion layer that is confined radially by an externally applied magnetic field are examined within the framework of the steady-state Vlasov-Maxwell equations. The selected distribution function not only allows radial confinement of the gyrating protons, but also is simple enough that explicit, analytic expressions can be obtained for the particle density, current density, magnetic field and the radii of the p-layer, without any a priori assumption about the radial dimensions of the layer. When the ion density is high, thin layer equilibria exist only for small rotational velocities, and for a small range of the conducting wall radius, the frequency of rotation can be considerably greater than the cyclotron frequency corresponding to the externally applied magnetic field.

Energy transport efficiency of an intense relativistic electron beam through a cusped magnetic field

A 500‐keV 40‐kA 50‐nsec‐duration relativistic electron beam is propagated through a cusped magnetic field. Conditions are reported which allow more than 85% of the beam energy to pass through the cusp.

Steady-state thermonuclear power generation in a two-energy-component Astron device

Studies are reported on a steady-state two-component Astron device. The basic idea is to confine a tritium plasma in a field- reversing deuterium ion layer and generate thermonuclear power from the optimized layer-plasma fusion reactions. The system is maintained at a steady state by the injection of neutral deuterium beams (150-300 keV). D-layer equilibrium and the power balance and power gain are discussed. (MOW)