GENERATION AND ENERGY ANALYSIS OF NEUTRAL C-60 SEEDED MOLECULAR-BEAMSUP TO 60-EV WITH ELECTROSTATIC ENERGY ANALYZER

We report on the detailed study and energy analysis of aerodynamically accelerated neutral C-60 Seeded molecular beams. Hyperthermal C-60 be ams with kinetic energies up to 56 eV in helium and 73 eV in hydrogen were generated and energy analyzed as a function of nozzle temperature and backing pressure. For these measurements a 90 degrees cylindrical energy analyzer was used in a continuous crossed beam mode with energ y resolution of Delta E/E = 0.07, instead of the conventional time-of- night technique. A narrow C-60 energy distribution (Delta E/E = O.11) is observed. The pronounced advantages of the energy analyzer method f or 1-100 eV seeded beams are discussed. No evidence was found for the high kinetic energy endohedral He@C-60 down to 0.5% detection limit.