A novel fast frequency modulation scheme for the JET multi-channel reflectometer
Several different modulation schemes are employed in reflectometer systems to determine the group delay time required for density profile measurements. The Joint European Torus (JET) multi-channel reflectometer uses slow, narrow-band sweeps of the microwave frequency in each of the channels. Ten channels of the original system are currently in operation, spanning the range from 18 to 70 GHz, in the O-mode. Problems are associated with this approach. To eliminate these problems and improve the general performance of this diagnostic, whilst retaining the advantageous aspects of the present system, a novel scheme relying on fast frequency modulation has been designed and is being implemented. The underlying theory and technical aspects of this novel system are discussed and illustrated with examples of preliminary measurements.
Bibliographic Reference: Report: JET-P(97)34 EN (1997) 11pp.
Availability: Available from the Publications Officer, JET Joint Undertaking, Abingdon, Oxon, OX14 3EA (GB)
Record Number: 199711730 / Last updated on: 1998-01-20
Original language: en
Available languages: en