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.

Circular electric mode microwave window

Abstract: For conducting very high microwave power at very high frequencies, circular waveguide transmitting a circular-electric-field mode is used. The vacuum-tight window of an electron tube is often the element with lowest power-handling capability. The inventive window has two dielectric plates with a space between them. There is a gap in the waveguide inner wall through which a dielectric fluid is circulated between the plates to cool them. The gap leads to a region containing wave-absorbing material such as water to absorb modes other than the circular-electric-field mode.

Coaxial receiver coil and capacitor structure for probes of uhf gyromagnetic spectrometers

Abstract: 1,150,248. Gyromagnetic spectrometers. VARIAN ASSOCIATES. April 7, 1967 [April 22, 1966], No. 16132/67. Heading G1N. To improve the signal to noise ratio in a gyromagnetic spectrometer probe, the length of the leads connecting the receiver coil 22, Fig.4, to its tuning capacitor 24 is decreased by placing the capacitor in the probe body, the capacitor having the form of two coaxial cylindrical or arcuate members arranged coaxial with the receiver coil former 23. In one embodiment the receiver coil 22 is mounted on the glass cylinder 23 which also carries a silver cylindrical or arcuate member 36 or (36 1 ), Figs.4, 7 (latter not shown), forming the fixed plate of the tuning capacitor and connected to one end of the coil by lead 35. The other end of the coil is connected both via lead 41 and coaxial cable 25 to external circuitry and via lead 37 to an r.f. earthed screw threaded brass plug 47 which may be screwed in and out of the member 36 and which forms the second plate of the capacitor. Alternatively, the plug 47 may be omitted, the second capacitor plate being provided by an outer screw threaded earthed metal cylinder (55, Fig. 6 not shown), or a semi-cylindrical screw threaded metal member (56, Fig.7 not shown). In all the embodiments a sample 1, Fig.3, in a vial 2, supported at its upper end by a spinner 21 by which the sample is rotated about the longitudinal axis, is placed in the tube 23, which is surrounded by a dielectric tube 28 on which the transmitter coil 27 is mounted with its axis perpendicular to that of the receiver coil. A dielectric tube 26, between the tubes 23, 38, coated with closely spaced longitudinal conducting strips, serves as a Faraday shield between the two coils 22, 27. The whole of this assembly is surrounded by the double walls 29, 31 of a dewar flask whose outer wall is in turn surrounded by a cylindrical assembly of magnetic field gradient cancelling coils 32, covered with an aluminium cylinder. In this spectrometer the unidirection magnetic field H 0 is provided by a superconducting solenoid (6, Fig. 1 not shown), surrounding the probe and immersed in liquid helium in a dewar flask (5) to keep the solenoid at superconducting temperatures. The spectrometer is operated using the side band technique by audio frequency modulation of the D.C. field H 0 which is also scanned and the recorder synchronized with the scan, Fig. 2 (not shown).

Methods and apparatus for fabricating a high purity thermally-conductive polymer layer

Abstract: Thermal transfer between a semiconductor wafer and a platen during vacuum processing is provided through a soft, thermally-conductive polymer layer having a thin, hard surface film. The soft polymer layer, which is preferably silicon rubber containing thermally-conductive particles, conforms to surface irregularities on the wafer and has low thermal resistance. The surface film is preferably silicon dioxide in the form of a multiplicity of flat plates integrally formed on the silicone rubber. Adherence of the wafer and of foreign matter to the polymer layer is prevented by the surface film. In addition, the underlying polymer layer is protected by the surface film. A high purity polymer layer is fabricated by evacuating the mold cavity and the resin container prior to injection of resin. The mold for the polymer layer utilizes a hard, smooth mold release surface and a resilient gasket between the platen and the mold release surface. The gasket establishes the dimensions of the polymer layer and seals the mold cavity. The surface film is formed by oxygen plasma treatment of the silicone rubber layer.

Method of operating an ion trap mass spectrometer

Abstract: A method of operating a quadrupole ion trap as a mass spectrometer, in which the ion mass to be detected is selected by adjusting the three dimensional quadrupole storage field to make the βz value of the selected mass equal to a fixed, predetermined βz value of a narrow range of frequencies excluded from a broadband supplemental RF electric field. The ions are detected to provide a signal corresponding to the amount of the selected ion mass.