What is it about?

This publication shows a newly developed pulse reflectometer diagnostic in the TCV tokamak. Pulse reflectometers were built in the 90s but abandoned because of various technical challenges. This work shows how a modern arbitrary-waveform-generator can be used to overcome these challenges and build the first broadband short pulse reflectometer. This diagnostic can resolve density profiles with a micro-second resolution, increasing the temporal sampling of density profiles in TCV by 4 orders of magnitude.

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Why is it important?

Measuring density profiles with higher speeds and resolution can help elucidate important physics on the edge of fusion plasmas. The study of dangerous instabilities, such as ELMs, is possible now with unprecedented experimental resolution.


I think this paper shows interesting technical improvements in the technique of pulse reflectometer. It shows it can be competitive with swept frequency reflectometers. It also opens the door to study turbulence with pulses, which has been largely unexplored by the community.

Pedro Molina Cabrera
Massachusetts Institute of Technology

Read the Original

This page is a summary of: V-band nanosecond-scale pulse reflectometer diagnostic in the TCV tokamak, Review of Scientific Instruments, December 2019, American Institute of Physics, DOI: 10.1063/1.5094850.
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