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Title: Recent improvements of the broadband FMCW reflectometry system for density profile measurements on ASDEX Upgrade

Journal Article · · Review of Scientific Instruments
DOI:https://doi.org/10.1063/1.2216992· OSTI ID:20861298
; ; ; ;  [1]
  1. Associacao EURATOM/IST-Centro de Fusao Nuclear, Instituto Superior Tecnico, Avenida Rovisco Pais 1, 1049-001 Lisbon (Portugal)

The broadband FMCW reflectometry system on ASDEX Upgrade has had significant improvements extending its measuring capabilities both on high and low density plasmas: (i) the upgrade of the W band to probe electron densities up to 12.4x10{sup 19} m{sup -3} with O mode (ii) Q and V frequency bands operating in X mode to probe the edge plasma and to provide information for O-mode profile initialization, and (iii) a new dynamic frequency calibration method to take into account all existing delays in the hyperabrupt varactor-tuned oscillator (HTO) tuning port and driver electronics. These improvements are particularly important to measure accurately the edge pedestal region of high density ITER relevant discharges. Density profiles obtained in high density discharges are presented and compared with results from both Li-beam and Thomson scattering diagnostics.

OSTI ID:
20861298
Journal Information:
Review of Scientific Instruments, Vol. 77, Issue 10; Other Information: DOI: 10.1063/1.2216992; (c) 2006 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0034-6748
Country of Publication:
United States
Language:
English