| 1. |
- Elevant, T., et al.
(författare)
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Profile Measurements in ITER by means of Neutron Spectroscopy, Ion Temperature Diagnostics for Experimental Thermonuclear Fusion Reactors
- 1996
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Ingår i: Workshop on diagnostics for ITER, Varenna, September 1995, proceedings of the International School of Plasma Physics, Edited by P. E. Stott et.al., Plenum Press, New York, 1996. - Boston, MA : Springer US. ; , s. 445-450
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Konferensbidrag (refereegranskat)abstract
- Information on ion temperature profiles will be needed for burn optimisation and transport studies in ITER. The feasibility of deriving these profiles for the core plasma (r< 0.75a) directly from the width of measured 14-MeV neutron energy spectra is demonstrated for Maxwellian ion distributions. Neutron energy spectra and fluxes generated under different heating conditions are calculated by means of Monte-Carlo technique. The computation takes the reaction kinematics and the velocity distributions of the reacting ions into account and calculates the resulting neutron energy distribution and flux into a defined collimator. Energy spectra of neutrons emitted along a line-of-sight are superimposed. The associated correction factor, which depends on the measured ion temperature, can be given an analytical form when fitted to code data and is insensitive to large variations in temperature-, density and magnetic flux profile shapes. The accuracy in ion temperature evaluation is expected to be better than ± 10% and can be improved to ± 5% provided information on fuel density profiles are made available.
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| 2. |
- Elevant, T., et al.
(författare)
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Role of Neutron Spectrometers for ITER
- 1998
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Ingår i: Proc. of the Int. School of Plasma Physics "Piero Calderola", Workshop on Diagnostics for Experimental Fusion Reactors, held September 4-12, 1997, in Varenna, Italy. Edited by Stott et al, Plenum Press, New York, 1998.
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Konferensbidrag (refereegranskat)abstract
- Conditions for retrieval of ion temperature profiles through measurement and evaluation of neutron energy spectra emitted in ITER-like fusion plasmas are discussed. Spectra from deuterium- and deuterium-tritium plasmas heated by 100 MW, 1 MeV neutral deuterium beams, and ignited H-mode plasmas are simulated by means of a Monte-Carlo Fokker-Planck code. Regions are defined where information on ion temperature clearly is preserved. The correction from line-of-sight integrated measurement to peak temperature is found to be 4–10% for deuterium plasmas of all temperatures and for deuterium-tritium plasmas of temperatures below approximately 5 keV. For higher temperatures the correction equals 10–30% depending on the density and temperature profiles. Ion temperatures can be determined with an accuracy better than 10% in this region only if profile data is made available.Several spectrometers have been proposed. Operating ranges in ion temperature and beam power, spatial- and temporal resolution, space requirements and life expectancy are compared with ITER measurement requirements. Necessary R&D work is also discussed.
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