Jet time of flight neutral particle analyzer

Neutral particle analyzers in large tokamaks are affected by the high neutron fluxes due to the sensitivity to neutrons of the particle detectors. The time of flight technique can be applied to a neutral particle analyzer providing at the same time the mass analysis and the random noise rejection mechanism. A time of flight neutral particle analyzer has been developed for the installation on JET providing 15 energy channels up to a maximum energy of 250 keV. The energy selection is performed by an electrostatic deflector and each energy channel consists of a time of flight detection system composed by two channeltrons, the first of which is triggered by the secondary electrons emitted by the incoming ion in a carbon foil. The analyzer has been calibrated with neutral beams of hydrogen, deuterium, and helium in the energy range (0.5, 200 keV)