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Title: Vertical localization of phase contrast imaging diagnostic in Alcator C-Mod

Abstract

Phase contrast imaging (PCI) diagnostic has been used to study mode conversion physics of ion cyclotron range of frequency waves [E. Nelson-Melby et al., Phys. Rev. Lett. 90, 155004 (2003)], plasma turbulence [A. Mazurenko et al., Phys. Rev. Lett. 89, 225004 (2002); N. Basse et al., Phys. Plasmas 12, 052512 (2005)], and Alfven Cascades [M. Porkolab et al., IEEE Trans. Plasma Sci. 34, 229 (2006)] in Alcator C-Mod. The C-Mod PCI system measures line integrated electron density fluctuations along 32 vertical chords with a sampling frequency of 10 MHz and wavenumber resolution up to 30 cm{sup -1}. Although PCI normally lacks localization along the chords, the vertical variation of the magnetic field pitch angle allows for localized measurements for large k{sub perpendicular} fluctuations. A system consisting of a partially masked phase plate on a rotatable stage has been installed and quasicoherent modes with wave number {approx}5 cm{sup -1} associated with the enhanced D{alpha}H mode at the top and bottom of the plasma have been differentiated. In future experiments, for k{approx}30 cm{sup -1}, a spatial resolution of r/a{approx}0.3 can be achieved under ideal conditions.

Authors:
; ; ; ;  [1]
  1. Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts, 02139 (United States)
Publication Date:
OSTI Identifier:
20861284
Resource Type:
Journal Article
Journal Name:
Review of Scientific Instruments
Additional Journal Information:
Journal Volume: 77; Journal Issue: 10; Other Information: DOI: 10.1063/1.2228623; (c) 2006 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0034-6748
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ALCATOR DEVICE; CYCLOTRONS; ELECTRON DENSITY; FLUCTUATIONS; MAGNETIC FIELDS; MHZ RANGE 01-100; MODE CONVERSION; PLASMA; PLASMA CONFINEMENT; PLASMA DENSITY; PLASMA DIAGNOSTICS; PLASMA INSTABILITY; SPATIAL RESOLUTION

Citation Formats

Lin, L, Edlund, E M, Porkolab, M, Lin, Y, and Wukitch, S J. Vertical localization of phase contrast imaging diagnostic in Alcator C-Mod. United States: N. p., 2006. Web. doi:10.1063/1.2228623.
Lin, L, Edlund, E M, Porkolab, M, Lin, Y, & Wukitch, S J. Vertical localization of phase contrast imaging diagnostic in Alcator C-Mod. United States. https://doi.org/10.1063/1.2228623
Lin, L, Edlund, E M, Porkolab, M, Lin, Y, and Wukitch, S J. 2006. "Vertical localization of phase contrast imaging diagnostic in Alcator C-Mod". United States. https://doi.org/10.1063/1.2228623.
@article{osti_20861284,
title = {Vertical localization of phase contrast imaging diagnostic in Alcator C-Mod},
author = {Lin, L and Edlund, E M and Porkolab, M and Lin, Y and Wukitch, S J},
abstractNote = {Phase contrast imaging (PCI) diagnostic has been used to study mode conversion physics of ion cyclotron range of frequency waves [E. Nelson-Melby et al., Phys. Rev. Lett. 90, 155004 (2003)], plasma turbulence [A. Mazurenko et al., Phys. Rev. Lett. 89, 225004 (2002); N. Basse et al., Phys. Plasmas 12, 052512 (2005)], and Alfven Cascades [M. Porkolab et al., IEEE Trans. Plasma Sci. 34, 229 (2006)] in Alcator C-Mod. The C-Mod PCI system measures line integrated electron density fluctuations along 32 vertical chords with a sampling frequency of 10 MHz and wavenumber resolution up to 30 cm{sup -1}. Although PCI normally lacks localization along the chords, the vertical variation of the magnetic field pitch angle allows for localized measurements for large k{sub perpendicular} fluctuations. A system consisting of a partially masked phase plate on a rotatable stage has been installed and quasicoherent modes with wave number {approx}5 cm{sup -1} associated with the enhanced D{alpha}H mode at the top and bottom of the plasma have been differentiated. In future experiments, for k{approx}30 cm{sup -1}, a spatial resolution of r/a{approx}0.3 can be achieved under ideal conditions.},
doi = {10.1063/1.2228623},
url = {https://www.osti.gov/biblio/20861284}, journal = {Review of Scientific Instruments},
issn = {0034-6748},
number = 10,
volume = 77,
place = {United States},
year = {2006},
month = {10}
}