Electronically swept millimeter-wave interferometer for spatially resolved measurement of plasma electron density.
We report the development and initial implementation of what we believe to be a new rapid- spatial-scan millimeter-wave interferometer for plasma density measurements. The fast scan is effected by electronic frequency sweeping of a wideband (180-280 GHz) backward-wave oscillator whose output is focused onto a fixed blazed diffraction grating. The system, which augments the rotating-grating scanned multiview H-1 heliac interferometer, can sweep the plasma cross section in a period of less than 1 ms with a beam diameter in the plasma of 20 mm and phase noise of the order of 0.01 rad.
Howard
John
J
Plasma Research Laboratory, Research School of Physical Sciences and Engineering, Australian National University, Canberra, ACT, Australia. john.howard@anu.edu.au
Oliver
David
D