Impurity identifications, concentrations and particle fluxes from spectral measurements of the EXTRAP T2R plasma

• An absolute intensity calibrated 0.5m spectrometer with optical multi-channel analyser detector was used to observe the visible-UV radiation from the plasma in the EXTRAP T2R reversed field pinch experiment. Spectral lines were identified indicating the presence of oxygen, chromium, iron and molybdenum impurities in the hydrogen plasma. Certain regions of interest were examined in more detail and at different times in the plasma discharge. Impurity concentration calculations were made using the absolute intensities of lines of OIV and OV measured at 1-2 ms into the discharge generating estimates of the order of 0.2% of ne in the central region rising to 0.7% of ne at greater radii for OIV and 0.3% rising to 0.6% for OV. Edge electron temperatures of 0.5-5 eV at electron densities of 5-10 x 10(11) cm(-3) were calculated from the measured relative intensities of hydrogen Balmer lines. The absolute intensities of hydrogen lines and of multiplets of neutral chromium and molybdenum were used to determine particle fluxes (at 4-5 ms into the plasma) of the order 1 x 10(16), 7 x 1013 and 3 x 10(13) particles cm(-2) s(-1), respectively.

Subject headings

NATURVETENSKAP  -- Fysik -- Fusion, plasma och rymdfysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Fusion, Plasma and Space Physics (hsv//eng)

Keyword

Carrier concentration

Impurities

Optical devices

Spectrometers

Spectrum analyzers

Ultraviolet radiation

Field pinch experiment

Multi-channel analysers

Plasma discharges

Plasmas

Plasma physics with fusion

Plasmafysik med fusion

Publication and Content Type

ref (subject category)

art (subject category)