Neutron emission spectroscopy at JET - Results from the magnetic proton recoil spectrometer (invited)

The principles and operation at Joint European Torus (JET) of the first mag netic proton recoil (MPR) spectrometer for measurement of fusion neutron sp ectra are described. Some technical aspects of the instrument are discussed , including energy calibration and monitoring system. Data from the recent experimental campaign with tritium at JET are presented as examples of the MPR's diagnostic abilities. It is shown that the spectrometer is a flexible and versatile instrument, capable of delivering high-quality data on a num ber of plasma parameters. In particular, the observation of the so-called a lpha knock-on effect in neutron emission spectroscopy is discussed. (C) 200 1 American Institute of Physics.