Particle and energy transport in tokamaks and other toroidal confineme
nt devices is dominated by turbulence generated by flows and gradients
. In order to understand and control of this transport, diagnostic ins
trumentation was developed to study the structure and magnitude of mic
roturbulent processes and to identify the origins of plasma loss. This
review will cover the primary instruments that have been developed to
measure fluctuating quantities associated with transport: density, Sn
, temperature, delta T, potential, delta phi, and magnetic field, delt
a B, and their correlations. The methods discussed are Langmuir probes
, heavy ion beam probes, collective and phase scintillation scattering
, beam emission and ordinary spectroscopy, reflectometry and enhanced
scattering, electron cyclotron emission, and several magnetic methods.
The emphasis here will be on techniques applicable to microturbulence
whose scale length is greater than the ion cyclotron radius and much
less than the minor radius. Limitations and strengths of each method w
ill be described and compared. Techniques will be discussed for estima
ting fluctuation intensities and wave number spectra or, equivalently,
multipoint correlations in radial, poloidal, and toroidal directions.
Large scale or magnetohydrodynamic-like plasma oscillations are typic
ally studied with tomographic techniques or external probes and are re
viewed elsewhere. (C) 1997 American Institute of Physics.