Experimental and theoretical study of the chemi-ionization in thermal collisions of Ne Rydberg atoms

The state dependence of associative ionization of the ns and nd Rydberg series of Ne atoms with 5<n<18 at thermal collision energies is investigated experimentally using a combination of synchrotron radiation and mass spectrometry in a single-beam experiment. The n dependence of the collisional and associative ionization of the Ne Rydberg atoms have been calculated using the dipole resonant mechanism, in particular the associative ionization rates for 5<neff<20 have been calculated for cell, single beam, and crossed beam conditions. Refinements of the theory implemented previously have been necessary in order to apply the theory to the collisions of rare gas atoms. The results of the theoretical model for the n dependency of the associative ionization rates of the Ne Rydberg atoms are compared to the experimental data.