Characterization of JET neutron field in irradiation locations for DD, DT and TT plasmas

• The neutron fluxes and spectra were characterized for four locations close to the plasma and related to activation experiments, as the preparation for the upcoming experimental campaigns in JET. The focus was on the study of a variance reduction technique in order to obtain statistically significant results in the parts of the neutron energy spectra, important for irradiation experiments. The DD, DT and TT plasmas were studied with the Monte Carlo hybrid method and the use of the ADVANTG program for generation of weight windows as variance reduction method to accelerate Monte Carlo simulations. The calculations were optimized to obtain low statistical uncertainties for all energy bins in the 640 energy group structure and for all three plasma sources. This included the acceleration of calculations for reaction rates of capture reactions, i.e. in the thermal flux region in irradiation positions on the first wall. Speed-ups due to use of the hybrid method in excess of two orders of magnitude were found with respect to analog calculations despite the vicinity of the plasma source.

Ämnesord

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

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

NATURVETENSKAP  -- Fysik -- Atom- och molekylfysik och optik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Atom and Molecular Physics and Optics (hsv//eng)

Nyckelord

JET

KN2 detector

Long-term irradiation station

Neutron transport calculations

ADVANTG

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