Minnesota Mining and Manufacturing Company

James T McKinney

Jerry Lee Alexander

John F Runyon

Daniel Charles Egan

Thomas W Rusch

Robert F Goff

A drive roller torque reference cartridge for calibrating a drive force tester. The reference cartridge uses a magnetic hysteresis brake assembly to controllably resist the rotation of the cartridge drive roller. The magnetic hysteresis brake assembly includes a cylindrical permanent magnet within the drive roller and a coaxial remanently magnetizable sleeve surrounding the drive roller. The drag created by the reference cartridge is substantially independent of the temperature and rotational speed of the drive roller.

Drive roller torque reference cartridge

An improved ion scattering spectrometer (ISS) in which a cylindrical mirror analyzer is provided and an ion gun for providing a beam of noble gas ions which are impinged upon and elastically scattered from a surface to be analyzed is axially positioned within the inner cylinder of the analyzer. A detector for ions passed through the analyzer is axially positioned proximate an energy resolving aperture located at the conjugate point of ions scattered from the sample to thereby detect ions having a narrow energy pass band. The analyzer has a substantially uniform response over a target area that is at least a thousand times the cross-sectional area of the ion beam impinged upon the target so that elemental imaging of the surface can be accomplished.

Ion scattering spectrometer including cylindrical mirror analyzer and

An ion scattering spectrometer (ISS) providing enhanced sensitivity, reduced background, and preferential detection of low-mass scattered ions over that of high-mass sputtered ions is disclosed. These advantages are accomplished by a biasing arrangement which maintains a potential difference between the analyzer exit and the detector input at less than 30 volts and substantially eliminates the high potential provided on detector inputs of prior art ion scattering spectrometers which attracted and thereby accelerated ions prior to impinging on the inputs.

Ion scattering spectrometer with modified bias

Improved apparatus and method for measuring ions scattered from a surface, to thereby determine the mass of atoms at the surface. The apparatus includes two analyzers, preferably an energy analyzer and mass analyzer positioned in tandem. The mass analyzer may be tuned to pass only ions having the same mass as ions in an incident ion beam, and to reject sputtered ions, some of which may have the requisite energy to pass through the energy analyzer under a given set of conditions.

Ion Scattering spectrometer with two analyzers preferably in tandem

A multipurpose apparatus is useful in either prefiltering ions or in forming ions from residual gases, prior to the analysis of the prefiltered or formed ions in a quadrupole type mass spectrometer. The apparatus includes a cylindrical grid, an annular entrance aperture wherein a center circular baffle has a unidimensional electrode extending along the axis of the grid, and a circular exit aperture, the axis of the grid being in line with the axis of a quadrupole type mass analyzer. The application of appropriate potentials to these members allows only low energy ions to pass therethrough and into the quadrupole analyzer. High energy ions or neutral particles having an axial trajectory are blocked by the baffle, while divergent high energy charged particles are insufficiently deflected and hence do not pass through the exit aperture. The apparatus further includes a filament positioned outside the grid, which, when energized, emits electrons. The electrons are accelerated toward the grid, passing therethrough whence they ionize residual gas atoms therein, which ionized atoms are extracted through the exit aperture and pass into the quadrupole analyzer.

Growing community of inventors

Stillwater, MN, United States of America

James T McKinney