VERTICAL VIEWING OF ELECTRON-CYCLOTRON EMISSIONS FOR DIAGNOSING FAST-ELECTRON DYNAMICS IN TEXT-U

A system for vertically observing the second-harmonic electron-cyclotron emissions from the TEXT-U tokamak in conjunction with fundamental electron-cyclotron heating is described. Using external collection optics and heterodyne receivers, measurements of the distribution function can be performed over two-thirds of the plasma radius and on transport time scales. Observations are typically of electrons with energy E<100 keV and either steep or shallow pitch angle, depending upon the toroidal viewing angle relative to the plasma current. © 1995 American Institute of Physics.