Multiposition Multipass Thomson Scattering Diagnostic for Tokamak NOVA-UNICAMP

Review of Scientific Instruments

2007

A vacuum ultraviolet spectrometer equipped with a charge coupled device and an open multichannel plate has been used to analyze the temperature of carbon and oxygen ions in the NOVA-UNICAMP tokamak. The detection system was optimized and aligned to minimize the instrumental broadening. Also, higher order diffractions of the emissions were analyzed, resulting in lower experimental errors. The ion temperature was monitored during the tokamak discharge, presenting values between 30 and 70 eV.

mentioning

confidence: 61%

Multichannel detector for ion temperature determination in vacuum ultraviolet spectrum

Review of Scientific Instruments

2007

“…The and values were obtained from Thomson scattering measurements [14], the excitation rate coefficients were taken from [11], and the total emissivity of the and were calculated from simultaneous measurements of the OIII 70.3 and 83.4-nm line emissions, respectively.…”

Section: B Br and Mbr Methodsmentioning

confidence: 99%

Modified branching ratio method for absolute intensity calibration in VUV spectroscopy

IEEE Trans. Plasma Sci.

2005

A new modified branching ratio (MBR) method for the absolute intensity calibration of a vacuum ultraviolet (VUV) spectrometer is presented. The spectrometer is equipped with a multichannel detector, consisting of an open microchannel plate coupled to a charge-coupled device (CCD), or with a single channel photomultiplier. This technique extends the number of calibration points available from those provided by the branching ratio (BR) calibration technique. The MBR method is a variation of the conventional BR method, where we relax the condition that the two spectral emissions, in the visible and VUV spectra, come from the same excited level, to include transitions from different sublevels of the same energy level. However, a critical study of the statistical equilibrium of sublevels from the same ion energy level was necessary. As a result, we have more than doubled the number of calibration points for our spectrometer used in tokamak plasma diagnostics. The appropriate identification of new spectral line pairs for absolute calibration here presented opens the path for future works in other devices with similar plasma conditions or impurities content.

“…11 At the limiter position, electron temperature and density, obtained with Langmuir probe, are T e Ϸ 10 eV and n e Ϸ 2.5ϫ 10 12 cm −3 , respectively. This is a small machine with 30 cm major radius and 6 cm minor radius.…”

Section: Introductionmentioning

confidence: 96%

Electron density and temperature determination using the concept of particle confinement time uniqueness

Review of Scientific Instruments

2005

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