Varian Associates

About: Varian Associates is a based out in . It is known for research contribution in the topics: Beam (structure) & Wafer. The organization has 2160 authors who have published 2591 publications receiving 46002 citations.

Air lock vacuum pumping methods and apparatus

Abstract: Method and apparatus for high speed vacuum pumping of an air lock. A vacuum pumped expansion tank having a volume larger than the volume of the air lock is coupled through a valve to the air lock. When evacuation of the air lock is desired, the valve is opened for a brief duration and the gas in the air lock rapidly expands into the expansion tank. Multiple pumping stages, each including a vacuum pumped expansion tank coupled through a valve to the air lock, can be utilized to decrease the final pressure in the air lock. The valves are sequentially opened to permit sequential expansion of the gas in the air lock into the expansion tanks. Multiple air locks can time share the same pumping system.

Grid coating for thermionic electron emission suppression

Abstract: In an electron gun having a control grid in contact with the face of the cathode, unwanted thermionic emission from the cathode can be effectively suppressed by applying a thin (1 micron) coating of boron nitride to the surface of the control grid. The boron nitride has low thermionic emission itself and, in addition, has an unusual ability to shed or eliminate any deposits of emissive material such as barium or its oxides which come in contact with the boron nitride layer. For optimum performance and longest lifetime, the boron nitride layer is applied over a pyrolytic graphite layer which may be the conductive grid itself.

Method and apparatus for automatic phase control in a fourier analyzed readout of impulse resonance data

Abstract: Method and apparatus for storing and reading out impulse resonance spectral data is disclosed. Impulse resonance spectral data containing a plurality of simultaneous Fourier components are added and time averaged in a computer or storage and adder. The stored resonance data is then Fourier analyzed to obtain a complex reference resonance line output containing a sum of both the real and imaginary parts of the time averaged resonance component. The resonance component is then analyzed for line symmetry to obtain an output representative of line symmetry. The line symmetry output is employed for changing the phase of both the real and imaginary components of the Fourier analyzed resonance component to reduce either the real or complex part of the resonance component to zero to obtain pure absorption or dispersion mode resonance spectra output.