Varian Associates

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

Inner wall coating of micro-LC columns. Wall effects in LC

Abstract: An elastic inner wall coating in the fused silica capillaries used for Micro-LC (LC on packed fused silica capillary columns) stabilizes the packed bed and thus increases column efficiency and life expectancy. Probably the particles of packing material are partly forced into the elastic polymer layer which thus holds the packing in position. Bonded polymers of very different chemical polarity can be used with equally good results. Variation of the coating layer thickness shows that there is an optimum value around 0.3 μm. A discussion of various wall effects in LC columns is presented. The i.d. of the columns is a most important parameter in this respect.

A gyro-TWT with a space-charged limited gun

Abstract: Most gyrotron traveling wave tubes (gyro-TWT) currently employ temperature-limited magnetron-injection electron guns to produce electron beams with high perpendicular to parallel velocity ratios. Certain problems with these guns have inspired the investigation of alternative space-charge-limited guns. An improved design technique applied to the helical transverse, magnetic "wiggler" employed in early cyclotron maser experiments shows promise for high power operation. A previously reported C-band gyro-TWT has been modified. The magnetron injection gun has been replaced with a Pierce-type electron gun. A bifilar helix of prescribed length capable of producing a helically varying transverse magnetic field for converting axial electron energy into transverse electron energy of low energy spread was placed between the Pierce gun and the rf interaction circuit. The rf interaction circuit was not changed. Substantial output power was achieved. Comparison of initial experimental results with previous results using the magnetron injection gun are presented.

High-temperature josephson junction and method

Abstract: A hysteretic high-T.sub.C. trilayer Josephson junction (10), and a method of forming the same are disclosed. The junction includes lower and upper high-T.sub.C superconducting cuprate films (18, 22) separated by a barrier layer (20), where the thin films each include a molecular junction layer adjacent the barrier layer which is characterized by a high-T.sub.C cuprate stoichiometry and crystal structure, and a flat two-dimensional surface, as evidenced by its electron diffraction pattern using reflected high-energy electron diffraction. The junction and barrier layers in the junction are formed by atomic layer-by-layer deposition.

Missing or broken wafer sensor

Abstract: Apparatus for sensing a missing or broken wafer in an automated wafer transfer system. The apparatus includes means for moving a wafer transfer mechanism from a first position along a prescribed path. A counter coupled to an oscillator is enabled when the wafer transfer mechanism and a wafer are moved away from the first position. A photosensor senses the presence of the wafer at a second position along the prescribed path and inhibits the counter. The count stored in the counter is compared with a predetermined count corresponding to the time required for movement of an unbroken wafer to the second position. If the counts do not agree, a missing or broken wafer is indicated and corrective action is taken.