Generation and energy analysis of neutral C60 seeded molecular beams up to 60 eV with electrostatic energy analyzer

We report on the detailed study and energy analysis of aerodynamically accelerated neutral C60 seeded molecular beams. Hyperthermal C60 beams 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° cylindrical energy analyzer was used in a continuous crossed beam mode with energy resolution of ΔE/E = 0.07, instead of the conventional time-of-flight technique. A narrow C60 energy distribution (ΔE/E = 0.11) is observed. The pronounced advantages of the energy analyzer method for 1–100 eV seeded beams are discussed. No evidence was found for the high kinetic energy endohedral He@C60 down to 0.5% detection limit.