Measurement of neutron emission profiles and neutron spectra by means of nuclear emulsions

A new method for simultaneous measurements of the 2.5 MeV neutron emission profile and the neutron spectra from tokamak fusion plasmas by using nuclear emulsions is presented. Measurements have been carried out near the plasma boundary at ASDEX. The measurements agree well with theoretical calculations. From the measured emission profile of a series of discharges with hydrogen injection, a deuterium temperature profile has been deduced. With the central value of the deuterium temperature taken from the spectrum analysis a consistent ratio of hydrogen density over deuterium density has been obtained. The results of our measurements are confirmed by data of the passive charge exchange diagnostics.