New developments in JET neutron, γ-ray
and particle diagnostics with relevance
to ITER
A. Murari, L. Bertalot, S. Conroy, G. Ericsson, V. Kiptily,
S. Popovichev, H. Schuhmacher, J.M. Adams, V. Afanasyiev,
M. Angelone, G. Bonheure, B. Esposito, J. Källne,
M. Mironov, M. Pillon, M. Reginatto, D. Stork, A. Zimbal
and JET-EFDA Contributors
Some recent JET campaigns, with the introduction of a trace amount (nT/nD < 5%) of tritium into D plasmas and
third harmonic ICRH acceleration of 4He, provided unique opportunities to test ‘burning plasma’ diagnostics. In
particular, new approaches and techniques were investigated for the detection of neutrons, α particles and the fuel
mixture. With regard to neutron detection, the recent activity covered aspects such as calibration and cross validation
of the diagnostics, measurement of the spatial distribution of the neutrons, particle transport and neutron spectrometry.
The first tests of some newneutron detection technologies were also undertaken during the Trace Tritium Experiment
campaign. To improve JET’s diagnostic capability in the field of α particles, a significant development programme
was devoted to the measurement of their confinement and imaging with γ -ray spectroscopy. A new approach for
the fusion community to measuring the fast ion losses, based on the activation technique, was also attempted for the
first time on JET. An assessment of the neutral particle analyser’s potential to determine the fuel mixture and the
particle transport coefficients is under way.