Molecular Beam Time-of-Flight Measurements for the Study of Metastable and Repulsive Electronic States

The time-of-flight distribution in an electrically neutral molecular beam has been analyzed, and from it the mass of the constituent molecules has been determined to an accuracy of about 5%. These experiments have been carried out on molecules in metastable electronic states, excited by pulsed electron bombardment and detected by an Auger process. Mass measurements, excitation functions, and electric deflection measurements verify that molecular beams of metastable benzene, toluene, and xylene can be formed. Molecular dissociation of N2O and CO2 due to electron impact was observed by Auger detection of dissociation products with high translational kinetic energy. The products are identified as metastable N2 and CO, respectively.