| 摘要 |
<p>The present disclosure is directed to a guide apparatus having a vacuum compartment which is at a background pressure and includes a gas inlet opening from which to jettison a gas in the form of a free jet stream from an exit end thereof into the direction of a bore of a duct. The duct is positioned along a trajectory axis of flow of the free jet stream and dimensioned to restrain free expansion of the free jet stream to form a laminar gas flow pattern downstream from the entrance end of the bore. The guide apparatus may be, for example, a mass spectrometer, a differential mobility spectrometer, or a mass spectrometer of the type including a compartment in a fore vacuum region which is configured to facilitate separation based on differential mobility properties of ions. A variety of duct configurations are described and contemplated. Also described and further contemplated are a variety of configurations in which two or more ducts of the same or different geometries are communicably coupled to one another. A method of setting the background pressure in the vacuum compartment of the guide apparatus is further provided.</p> |
