| 摘要 |
PURPOSE:To selectively form and collect objective fine particles, by sending a fine particle stream to a collecting position in the form of a pulsated stream. CONSTITUTION:When fine particles are supplied into an upstream chamber 2 and a downstream chamber 3 is evacuated, fine particles flow through a contracting and expanding nozzle 1 from the upstream chamber 2 to flow in the downstream chamber 3. The contracting and expanding nozzle 1 can inject fine particles as a proper expanding stream of ultrasonic velocity by regulating the pressure ratio of the upstream chamber 2 and the downstream chamber 3 corresponding to the opening area ratio of a throat part 1b and an outflow part 1c. When fine particles are injected in a definite direction by this method, the fine particles straightly advance while the cross-section of the jet stream immediately after injection is generally held to be formed into a beam. Subsequently, the fine particle stream is pulsated by a pulsating means 5 and sent to a substrate 4 to be collected. That is, the fine particles are transferred through the space in the downstream chamber 3 in min. diffusion at ultrasonic velocity in an independent state and an objective product is grown or formed by reaction and the fine particle stream is sent to a collecting position only for a time when no other product is formed. |
