Ion Temperature Profile Measurements at JET Using the Upgraded Neutron Profile Monitor
The neutron profile monitor is routinely used at the Joint European Torus for neutron emissivity profile measurements. The diagnostic consists of two fan-shaped arrays of collimators and each line of sight is equipped with a NE213 liquid organic scintillator for simultaneous measurements of the 2.5MeV and 14MeV neutrons. The diagnostic has been upgraded by replacing its analog acquisition electronics with a digital system developed in ENEA. The new acquisition chain enables the NPM to perform spatially-resolved neutron spectrometry by providing neutron pulse height spectra for each LOS. However, the conditions for neutron spectrometry with the NPM are not optimal since this diagnostic was not originally designed as a spectrometer and therefore lacks several key features, such as detailed measurements of the detector response functions and the presence of detector stability monitors. In this paper, a proof of principle of ion temperature profile measurements derived from the NPM PHS in high plasma current discharges using simulated detector response functions are presented.