Magnetic compression heating experiments at the 1 GW level on field-reversed configuration (FRC) compact toroid plasmas are reported. FRC’s formed in a tapered theta-pinch coil have been translated into a single-turn compression coil, where the external magnetic field is slowly raised up to seven times its initial value. Significant electron and ion heating consistent with the expected B4/5 adiabatic scaling is observed, despite significant particle diffusion, which is enhanced during compression. The n=2 rotational instability is enhanced during compression, but has been controlled to an extent by the application of an external quadrupole field. The particle and flux confinement times, τN and τφ, remain approximately equal and decrease roughly with the square of the plasma radius R during compression, implying a constant nonclassical field-null resistivity. The observed τN and τφ magnitudes and scalings are compared with classical and anomalous transport theories, and existing empirical models. Particle diffusion dominates the energy confinement, accounting for three-fourths of the total losses. Upper bounds on the electron thermal diffusivities are estimated.

Data from an array of external probes provide the first clear evidence for the n=1 rotational instability in field-reversed configurations. The time evolution and the axial structure of this instability are clarified.

Electron energy transport in field reversed configuration (FRC) equilibria is studied experimentally for a variety of conditions. Up to 37% of the global plasma power loss is attributed to non-convective processes by electrons. The electron temperatures are approximately two times larger than those measured without reversed bias field, which indicates confinement by the poloidal magnetic field in the FRC. The inferred average cross-field thermal diffusivities χ⊥e are anomalous, ranging between 35 and 140 times classical, and are consistent with transport from turbulent magnetic fluctuations of 1 to 2%.

The poloidal magnetic flux φ in large field-reversed configuration plasmas is examined experimentally. A wide range of initial equilibrium conditions, with 1≤φ≤8 mWb, is produced by varying the reverse bias magnetic field strength. The flux confinement time τφ at first improves with bias, albeit with field-null resistivities an order of magnitude larger than classical. A further increase in bias results in a reduction of τφ, which is inconsistent with either classical or anomalous diffusion theory. The data suggest the importance of nondiffusive processes such as instabilities or formation dynamics.

In order to gain an insight into the effects of a space environment on materials, thin aluminum samples were exposed to an oxygen plasma produced by an electron beam. Using Rutherford backscattering spectrometry the samples exposed to the oxygen plasma were compared to samples exposed to ordinary oxygen gas. The comparison revealed a considerable increase in oxygen diffusion in the samples exposed to the charged particle environment. The amount of oxygen diffusion depends on the duration of the plasma exposure.