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.

Heat unit integrator for x-ray tubes

Abstract: PATENT APPLICATION For HEAT UNIT INTEGRATOR FOR X-RAY TUBES By John T. Perry Joel J. Schmutzer ABSTRACT Apparatus to indicate the temperature of an X-ray tube target includes an analog storage circuit to simulate the heat energy stored. Input signals representing the current and the voltage of the electron beam in the tube are multiplied to give a signal representing the instantaneous power input. The power signal is integrated in the storage circuit to give a temperature signal representing the total heat. input. The temperature signal is dissipated by a cooling curve circuit representing the heat loss with time.An indicator reads the temperature signal. Input voltage and current signals are processed to refer them to ground before multiplication. The current signal is corrected to set its zero value. The voltage signal derived from a transformer primary is corrected for transformer regulation. To eliminate spurious inputs the power signal is gated to the storage circuit only when a measured current is flowing. Multiple storage circuits indicating a number of tubes remember the temperature of their own targets while the power signal and the temperature indicator are being used with another storage circuit.

Magnesium doping of efficient GaAs and Ga(0.75)In(0.25)As solar cells grown by metalorganic chemical vapor deposition

Abstract: Magnesium has been substituted for zinc in GaAs and Ga(0.75)In(0.25)As solar cells grown by metalorganic chemical vapor deposition (MOCVD). Bis(cyclopentadienyl)magnesium (Cp2Mg) is used as the MOCVD transport agent for Mg. Full retention of excellent material quality and efficient cell performance results. The substitution of Mg for Zn would enhance the abruptness and reproducibility of doping profiles, and facilitate high temperature processing and operation, due to the much lower diffusion coefficient of Mg, relative to Zn, in these materials.

Anion exchange chromatographic separation of polyfunctional compounds

Abstract: A weak anion exchange composition useful in polyfunctional compound chromatographic separations comprises an inert porous particle having a tetra-substituted silane material fixedly attached by covalent bonding to the surface thereof. A process for synthesizing the weak anion exchange composition is disclosed together with methods for separation of polyfunctional compounds and their isomers using a column packed with such weak anion exchange composition.