Diagnostics for hot-electron, magnetically confined plasmas

TLDR: In this paper, the authors developed a set of diagnostics for measuring the temperature, density, velocity distribution, axial and radial profiles, and decay rate, of a hot-electron (te between 20 and 200 kev) plasma confined in a magnetic mirror field.

Abstract: Diagnostics have been developed for measuring the temperature, density, velocity distribution, axial and radial profiles, and decay rate, of a hot-electron (te between 20 and 200 kev) plasma confined in a magnetic mirror field. The diagnostics include the measurement of: (1) the magnitude, spectrum, and spatial distribution of the synchrotron radiation, for determining the hot- electron line density, speed distribution, and density profile and angular velocity distribution, respectively; (2) the relativistic X-ray pulse heights, for determining the speed distribution; (3) the relative spatial distribution of visible light, for determining the density profile; and (4) microwave cavity frequency shifts, for determining the electron number. Comparison among these diagnostics is made. It is shown that measurements of temperature, density, and axial profile can be considerably in error if the experimental results are compared with maxwellian velocity distributions, rather than self-consistent, mirror distributions. Theoretical curves of X-ray pulse height distributions and absolute synchrotron radiation spectra are given for a self-consistent velocity distributions applicable to a wide range of hot-electron plasmas.