Abstract: A mass spectrometer is described in which the ions are submitted to the action of a uniform adjustable electrical field {right arrow over (E)}1, within a set of plane parallel electrodes a1, . . . , ai, . . . an fitted with properly located slits for the ions transmission, and to the action of a uniform magnetic induction {right arrow over (B)}1. A reference system x,y is considered in a plane perpendicular to {right arrow over (B)}1, the axis x and y being respectively perpendicular and parallel to {right arrow over (E)}1, and the origin of the reference system being fixed at an average starting point of the ions. The crossed fields {right arrow over (E)}1,{right arrow over (B)}1, act together in an area where y<d and the magnetic induction {right arrow over (B)}1 acts alone in a further area where y>d, d being a distance separating the average starting point of the ions from the electrode &agr;n.

Abstract: A mass spectrometer is disclosed which includes an ionizer, a collector slit disposed at a predetermined distance from the ionizer, and an electrostatic field source disposed between the ionizer and the collector slit. The electrostatic field source has a selected amplitude which is substantially uniform within a space between the ionizer and the collector slit. The electrostatic field is oriented substantially perpendicular to a line between the ionizer and the collector slit. The mass spectrometer includes a magnetic field source disposed between the ionizer and the collector slit. The magnetic field source induces a substantially uniform magnetic field within the space. The magnetic field has a direction perpendicular to both the electrostatic field and to the line between the ionizer and the collector slit. The spectrometer includes a detector disposed behind the collector slit.

Abstract: A mass spectrometer is described in which the ions are submitted to the action of a uniform adjustable electrical field {right arrow over (E)}1, within a set of plane parallel electrodes a1, . . . , ai, . . . an fitted with properly located slits for the ions transmission, and to the action of a uniform magnetic induction {right arrow over (B)}1. A reference system x,y is considered in a plane perpendicular to {right arrow over (B)}1, the axis x and y being respectively perpendicular and parallel to {right arrow over (E)}1, and the origin of the reference system being fixed at an average starting point of the ions. The crossed fields {right arrow over (E)}1,{right arrow over (B)}1, act together in an area where y<d and the magnetic induction {right arrow over (B)}1 acts alone in a further area where y>d, d being a distance separating the average starting point of the ions from the electrode &agr;n. The selection slit S1 is located at coordinates x=2.

Abstract: An ion source for a quadrupole mass spectrometer comprises, from the upstream end to the downstream end in the axis of the quadrupole, an ionization chamber with heated filament and electrostatic field associated with an electron-optical system provided with an electron convergence device. A uniform magnetic field is superimposed on the electrostatic field of the ionization chamber. The electron-optical system comprises a first extraction electrode having a downstream surface which is at least approximately spherical, a second coaxial electrode in the form of a disk having a central orifice of relatively substantial width and, at a short distance, a third electrode in the form of a disk having a relatively small central orifice, the potentials of the electrodes being so adjusted as to form hemispherical equipotential surfaces between the first and the second electrode.

Abstract: A mass spectrograph combining one or more magnetic deflections with the action of electrostatic fields, characterized by the fact that the system is circularly symmetrical; by the fact that the ions are injected radially from a source constituted by a heated circular filament and a pair of small ring-shaped magnets which confine the ionizing electrons to the interior or exterior periphery of the analyzer system per se; by the fact that the first pair of deflection magnets of the analyzer system is ring shaped; and by the fact that the selective action of the other fields, in particular the electrostatic fields, is due to the prior dispersion obtained by the first magnetic induction.

Abstract: Dry vacuum diaphragm pump, for pumping between an inlet port (2) and an exhaust port (3), and comprising a tubular diaphragm (12) retained by its resilience on a central body (11) in the biconical interior volume of a body (1), in such manner as to form a pumping chamber (15) into which debouch inlet and exhaust ports, and a control chamber (16).Port (3) communicates through a valve (7) with a capacity (9) maintained under partial vacuum by an auxiliary vacuum pump (23).The distribution mechanism (20, 21, 27) places the chamber (16) in communication alternatively with atmosphere and with the intake of the auxiliary pump (23).