Optimum beam diameter for microwave reflectometer measurements
Microwave reflectometry has two diagnostic applications for fusion plasmas. It can be used to measure the electron density profile using swept or multiple microwave frequencies, and it can be used to measure density and magnetic field fluctuations. In many cases the same diagnostic apparatus has been used for both purposes. However there appears to be some uncertainty over the most suitable reflectometer beam diameter for each type of measurement. Simulation results of the reflectometer phase and power sensitivity from a two-dimensional physical optics model show that a tightly focused reflectometer beam is most appropriate for fluctuation measurements, while a larger beam diameter appears more appropriate for density profile measurements.
Bibliographic Reference: Report: JET-P (97) 15 EN (1997) 6pp.
Availability: Available from the Publications Officer, JET Joint Undertaking, Abingdon, Oxon OX14 3EA (GB)
Record Number: 199711264 / Last updated on: 1997-10-10
Original language: en
Available languages: en