Computerized tomography of plasma in laboratory and space

Computerized tomography (CT) can be applied in plasma physics, however, some special problems, screening, diffraction, nonlinearities, poor temporal distribution limit the applicability and the accuracy of the CT results. The basic mathematical concepts of CT are formulated by terms of integral geometry. The related problems of plasma diagnostics are discussed from the simplest parameter-fitting of symmetric objects by rectilinear ray trajectories to the most complex problem of imaging asymmetric, inhomogeneous objects by distorted, refracted curvilinear ray trajectories. Some examples are given for the methods worked out in detail: the CT of arc discharges and plasma jets, the use of CT in tokamak and stellarator plasma diagnostics and in analysis of laser produced plasmas. Mathematically and physically related astrophysical problems (star clusters, solar corona) are noted as well. Development trends of the topic are surveyed. (D.Gy.)