A calibrated neutral atom spectrometer for measuring plasma ion temperatures in the 0.165- to 10-keV energy region

A neutral spectrometer, consisting of a gas conversion cell and electrostatic energy analyser, has been designed, constructed, and calibrated to measure the energy dispersion of energetic H- or D-atoms escaping a plasma. For energies less than 300 to 500 eV the D-atom conversion to D + was greater than that of H-atom conversion to H + . At a target density of 0.0125 Torr-cm the conversion efficiency of H in N 2 gas is 3.8 × 10 −4 at 0.165 keV and increases to 3.3 × 10 −2 at 10 keV. Results for H 2 conversion gas were an order of magnitute less than that of N 2 at the lower energies.