Calibration and test of the tangential phase contrast imaging diagnostic on CDX-U (abstract)

Journal Article · Wed Jan 01 04:00:00 EST 1997 · Review of Scientific Instruments

DOI:https://doi.org/10.1063/1.1147675· OSTI ID:451837

Lo, E; Nazikian, R; Stutman, D; Choe, W; Kaita, R ^[1]

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1. Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543-0451 (United States)

The novel CO{sub 2} laser based tangential imaging diagnostic has been completely calibrated and the system has been tested on CDX-U plasmas. It has been shown that localized, two-dimensional images of the plasma electron density fluctuations in the tokamak core can be obtained from a tangential imaging beam.1 A variation of the Zernike phase mirror is used. Test measurements made on soundwaves verify that the system will image phase variations placed at the object plane. An absolute sensitivity of {approx}1{times}10{sup 7} cm{sup {minus}3}/{radical}(Hz) has been determined. A series of plasma measurements made on CDX-U are described. Results show that the plasma fluctuations are 2{endash}3 orders of magnitude above the noise floor of the diagnostic. It is also verified that a high-pass cutoff wave number (from {approx}1{endash}8 cm{sup {minus}1}) for the fluctuations can be selected by translating the phase mirror. The density fluctuation {ital k} spectrum is measured and found to peak at {approx}1{endash}3 cm{sup {minus}1}.{copyright} {ital 1997 American Institute of Physics.}

• OSTI ID: 451837
• Report Number(s): CONF-960543--
• Journal Information: Review of Scientific Instruments, Journal Name: Review of Scientific Instruments Journal Issue: 1 Vol. 68; ISSN 0034-6748; ISSN RSINAK
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
CALIBRATION
CARBON DIOXIDE LASERS
ELECTRON DENSITY
FLUCTUATIONS
IMAGES
LINEAR Z PINCH DEVICES
NOISE
PINCH EFFECT
PLASMA DENSITY
PLASMA DIAGNOSTICS
SENSITIVITY
TESTING
TOKAMAK DEVICES
plasma fluctuations
plasma toroidal confinement