GENERATION OF FINE-PARTICLE BEAMS AND THEIR APPLICATIONS.

A collimated beam of fine-particles (diameter, 5-100 nm) of metals, semimetals or oxides was generated by injecting smoke into a vacuum chamber in which the gas was evacuated by differential pumping. The speed of the particles in the beam was estimated to be about 120 m/s by measuring the deviation from a horizontal line due to gravity. A silver beam was bombarded with electrons and deflected by an electric field. Neutral as well as negatively and positively charged particles co-existed in the beam for bombarding energies between 50 to 160 V. The speed of charged particles was measured to be about 200 m/s by a time-of-flight measurement. A beam of gold or silicon was injected directly into the specimen stage of a TEM so that smoke particles could be studied without exposure to air. Particles in the beam were heated with radiation or coated with metal in the vacuum.