Abstract: A multi-stage valve having a valve housing containing an inlet port and an outlet port that communicate through means of an elongated chamber formed in the housing. An outer sealing unit is mounted in the chamber and is adapted to close in sealing contact against one of the ports. A control orifice is passed through the first sealing unit to restrict the flow through the port when the unit is sealed thereagainst. A second inner sealing unit is mounted in the chamber behind the outer unit and is arranged to close thereagainst to seal the orifice. The two units are coupled by a lost motion mechanism which permits the sealing units to close in sequence between a fully closed position, an intermediate position wherein the flow through the valve is restricted by the orifice and a fully opened position wherein the flow through the valve is unrestricted.

Abstract: Method and apparatus for monitoring the deposition of a material or materials upon a substrate using atomic absorption techniques. Radiant energy is directed through a flow of evaporant during a deposition process. The radiation contains spectral emission lines absorbable by the evaporant as well as emission lines not absorbable by the evaporant. Changes in the transmission of one or more non-absorbable lines are used to compensate for changes in the absorption of absorbable lines of interest that are caused by misalignment or displacement of the optical elements during the deposition process.

Abstract: An RF control system suitable for use in a mass spectrometer of the type having an ionization chamber, a mass filter and an ion detector. A constant frequency RF voltage is applied to the filter. The magnitude of the RF signal is varied in response to a DC control signal to permit selected ions having a desired charge-to-mass ratio to pass through the filter and strike the detector. In the control system the generated RF signal is attenuated and added to the DC control signal. The resultant voltage is applied to a comparator-integrator circuit that is arranged to provide a control signal capable of precisely holding the output of the RF generator at a predetermined peak voltage.

Abstract: A method of manufacturing a solid state sensor wherein a reactive compound of an alkali metal is tightly packed between a central electrode and a surrounding ion shield. A heating coil is wound about the outside of the shield. The ion shield is formed of a material that is deplete in ions of alkali metal and serves as a ion depletion boundry in the system.

Abstract: Method and apparatus for selectively sensing the presence of a given constituent within an atmosphere. The apparatus includes a solid state element containing alkali metal ions that react with ions of the given constituent when the two are brought together. The solid state element is housed within a shield that functions as an ion control screen when heated to a predetermined temperature in the presence of a gas or vapor of the given constituent to selectively pass ions of the given constituent into reactive contact with the solid state element housed therein. Circuit means are further provided for detecting a flow of ions through the shield and for producing a discernible signal in response thereto.

Abstract: A leak standard generator which utilizes the diffusion properties of a gas or vapor to deliver a uniform rate of flow of a leak sample into a diluent gas stream. The generator includes a reservoir containing the leak sample, a discharge head through which is passed a metered flow of diluent gas and a diffusion tube of prescribed dimensions for carrying a gas or vapor of the sample from the reservoir into the diluent gas stream moving through the discharge head. Heating means are provided to maintain the reservoir and the diffusion tube at different temperature levels to promote uniform movement of the sample gas or vapor into the diluent stream.

Abstract: Apparatus is disclosed for utilizing a low energy electron beam to permit monitoring the rate of deposition and composition of the evaporant particles in a vacuum deposition system. This is accomplished by passing a sample of the evaporant employed in the vacuum deposition process through an enclosure defining a flow path for the evaporant sample which crosses the path of a relatively low energy electron beam which is sufficient to excite the electrons of the atoms constituting the vaporized particles in the deposition chamber. The outer-shell electrons of the atoms constituting the evaporant, after excitation, drop back to a lower energy state in the course of which photons are released which are characteristic of given materials. The enclosure is formed with an optical opening receiving the photons in a path orthogonal with respect to the excitation beam and evaporant sample path, and a photodetector is optically coupled to the opening for sensing the emitted photons.