| 摘要 |
Suspended particles which may be small solids or liquid particles or particles consisting of both solid and liquid components or relatively heavy molecules suspended in a lighter suspending gas are formed into a continuum source particle beam upon expansion of the suspension through a nozzle into a vacuum environment. The flow of the particle containing gas into the nozzle is confined by a flow of clean, particle free gas, as between a core and a sheath thereof, such that the particles have the same position at the inlet of the nozzle or at some location downstream of the inlet, such as the exit of the nozzle, thereby allowing only those particles containing the trajectory corresponding to the selected particle properties to be transmitted through one or more collimator holes or skimmers which are disposed a sufficient distance from the nozzle exit. The particle properties which determine their trajectory are particle mass and dimensions. The controlled flows into the nozzle enable the location, shape and dimensions of the collimator holes to be specified in accordance with the trajectory of the particles of selected mass and dimensions to be separated. Through the use of a plurality of collimators which define different angles, the resolution of particles which may be separated may be increased by defining double valued, narrow transmission functions.
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