V-band Doppler backscattering diagnostic in the TCV tokamak.
P Molina CabreraS CodaL PorteN OffedduP LavanchyM SilvaM Toussaintnull nullPublished in: The Review of scientific instruments (2018)
A variable configuration V-band heterodyne Doppler back-scattering diagnostic has been recently made operational in the tokamak à configuration variable. This article describes the hardware setup options, flexible quasi-optical launcher antenna, data-analysis techniques, and first data. The diagnostic uses a fast arbitrary waveform generator as the main oscillator and commercial vector network analyzer extension modules as the main mm-wave hardware. It allows sweepable single or multi-frequency operation. A flexible quasi-optical launcher antenna allows 3D poloidal (10°-58°) and toroidal (-180° to 180°) steering of the beam with 0.2° accuracy. A pair of fast HE11 miter-bend polarizers allow flexible coupling to either O or X mode and programmable polarization changes during the shot. These have been used to measure the magnetic-field pitch angle in the edge of the plasma by monitoring the backscattered signal power. Ray-tracing simulations reveal an available k⊥ range between 3 and 16 cm-1 with a resolution of 2-4 cm-1. Perpendicular rotation velocity estimates compare well against ExB plasma poloidal rotation estimates from charge exchange recombination spectroscopy.
Keyphrases
- data analysis
- solid state
- high resolution
- blood flow
- high speed
- single molecule
- magnetic resonance imaging
- monte carlo
- gene expression
- electronic health record
- genome wide
- magnetic resonance
- machine learning
- big data
- network analysis
- dna repair
- mass spectrometry
- room temperature
- image quality
- electron microscopy
- contrast enhanced