出版社:SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要:During past experimental campaigns at JET, the NE213 liquid scintillator proved to be a valid
diagnostic tool for spectral measurements of fusion neutrons emitted from the plasma. The
scintillator response function to neutrons is derived from theoretical estimation combined with
measurements at an accelerator-based neutron source. The spectrum unfolding poses an illconditioned
inversion problem similar to tomographic reconstruction.
Minimum Fisher Regularisation (MFR) is one of the established methods in plasma 2D
tomography, providing a rapid and robust tool for sparse data inversion without special a priori
assumptions. In neutron analyses at JET, the MFR has been applied both in tomography (see
contribution by G. Bonheure) and in unfolding the NE213 spectra, where good agreement with
results of the standard Maximum Entropy unfolding procedure (MAXED) was demonstrated.
This contribution is focussed on further progress in the MFR application to the unfolding of
NE213 spectra. In particular, the L-curve maximum curvature optimisation was implemented
which gives MFR the full independence required for automated operation. New results are
presented in comparison with the MAXED analyses. The differences between the data and the
retrofit of the unfolded spectra are studied and the MFR potential for future applications is
outlined.