IONIZATION OF METASTABLE NEON BY ELECTRON-IMPACT

The partial electron impact ionization cross section for metastable ne on, Ne-+, has been measured in the energy range from threshold to 200 eV. The crossed-beam experiment used a fast neutral target (both grou nd state and ground state plus metastable) formed by charge transfer b etween an 800 eV neon ion beam and neon gas or sodium vapour. The ioni zation cross section for the P-3(2) and P-3(0) metastable components, which are assumed to be equal, was placed on an absolute scale by util izing the known ground-state cross section and assuming that the beam fractions of the mixed state were statistically distributed. The resul ts are compared with previous experimental and theoretical work.