Proposed Neutron Emission Spectroscopy Diagnostics of Energetic Deutrons in JET rium Plasmas

• The DT experimental campaign on JET (1997) represented a major step forward for neutron emissionspectroscopy (NES) diagnostics thanks to the high count rate measurements obtained with themagnetic proton recoil (MPR) neutron spectrometer in high fusion yield plasmas [1]. NESmeasurements were made on JET DT plasmas for different heating conditions including thosegenerating energetic deuterons either directly through NB injection, or through ICRH accelerationusing the (D)T minority scheme [2]. A multiple-component model has been developed for analysisof dt neutron spectra that is based on a simplified description of fuel ion velocity distributions fordifferent heating conditions [3,4]. The same model is used here for projections of NES spectra fromJET deuterium plasmas using the dt results as input. This is done on the basis of a system of twocomplementary NES instruments, the TOFOR (Time of Flight - Optimized Rate) [5] and MPRu(Magnetic Proton Recoil Upgrade) spectrometers that are presently proposed for installation onJET [6]. Both spectrometers would record neutron spectra in D plasmas but for different viewinglines. TOFOR would have a “vertical” view, i.e. at an angle of 90° relative to the toroidal magneticfield. This is the same viewing line used for some of the previous dd NES measurements on JET[7]. MPRu would have a “tangential” view, i.e. horizontal (on the equatorial plane) at an angle of47° relative to the toroidal magnetic field and opposite to the beam injection direction. This is thesame viewing line used for the 1997 dt measurements using the magnetic proton recoil (MPR)spectrometer.Projections of dd neutron spectra under the assumptions above are used here for an assessmentof the performance and requirements of NES as a diagnostic of energetic deuterons in JET.

Subject headings

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

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

Keyword

nuclear fusion

plasma physics

neutron emission

neutron spectroscopy

MPR neutron spectrometer

TOFOR neutron spectrometer

D plasma

DT plasma

ICRH heating

NBI heating

Plasma physics with fusion

Plasmafysik med fusion

Publication and Content Type

vet (subject category)

kon (subject category)