Quantitative method for precise, quick, and reliable alignment of collection object fields in the JT-60U Thomson scattering diagnostic

Journal Article · Sat Feb 01 04:00:00 EST 1997 · Review of Scientific Instruments

DOI:https://doi.org/10.1063/1.1147877· OSTI ID:451078

Yoshida, H; Naito, O; Matoba, T; Yamashita, O; Kitamura, S; Hatae, T; Nagashima, A ^[1]

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1. Japan Atomic Energy Research Institute, Naka Fusion Research Establishment, Naka-machi, Naka-gun, Ibaraki 311-01 (Japan)

The design concept and operation performance of a novel alignment system for accurate electron density profile measurement is presented, which has been developed on the basis of the original method for adjusting quantitatively and actively an object field of collection fiber optics to a laser-beam axis. The quantitative expression needed for an appropriate alignment was able to be formulated using the beam width measured {ital in situ} by this alignment system and the four laser scattering intensity signals from special alignment fiber bundles. The effectiveness of this alignment system for precise and reliable measurement of electron density has been successfully demonstrated in the JT-60U Thomson scattering diagnostic through direct monitoring and quick restoration of alignment. The important and distinctive feature of this alignment system is to attain compatibility between a stable and accurate maintenance of alignment and an improvement of the signal-to-noise ratio of Thomson scattering to plasma light accompanying the reduced fiber bundle width. {copyright} {ital 1997 American Institute of Physics.}

• OSTI ID: 451078
• Journal Information: Review of Scientific Instruments, Journal Name: Review of Scientific Instruments Journal Issue: 2 Vol. 68; ISSN 0034-6748; ISSN RSINAK
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ALIGNMENT
DESIGN
ELECTRON DENSITY
FIBER OPTICS
JT-60U TOKAMAK
LIGHT SCATTERING
OPERATION
OPTICAL FIBERS
OPTICAL SYSTEMS
PERFORMANCE
PLASMA DENSITY
PLASMA DIAGNOSTICS
SIGNAL-TO-NOISE RATIO
THOMSON SCATTERING