DEVICE FOR EXTRACTION OF PARTICLES Russian patent published in 1998 - IPC

FIELD: cathode-ray technology. SUBSTANCE: device for extraction of particles includes differential pumping chamber that has holes for connection to vacuum pumping out aids and inlet and outlet holes with flight branch pipes for outlet of particles from reduced pressure region to increased pressure region arranged uniaxially. Branch pipes are manufactured in the form of hollow truncated cones facing inside of chamber with vertexes. Side wall of inlet branch pipe has through holes. In this case distance h between branch pipes satisfy expression $$$, where d is diameter of hole at vertex of outlet branch pipe; k is index of gas adiabatic curve; p is pressure in plane of cut of vertex of outlet branch pipe; R<Mv>1<D> is pressure in chamber outside jet. EFFECT: increased diameter of extracted beam.