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.

In-situ synthesis and growth of indium phosphide

Abstract: The high partial pressure of phosphorus at the stoichiometric melting point of InP precludes the in-situ synthesis in the puller by simple admixture of indium and phosphorus. This paper describes a system that was considered for the in-situ synthesis and growth of InP single crystal, utilizing the phosphorus vapor injection method. The advantages of this two-heater side-by-side injection synthesis system is dis-cussed and the effect of chamber pressure and phosphorus temperature on the InP synthesis yield is described. The procedures used for in-situ synthesis and growth are also described. Electrical and optical properties of LEC cry-stals grown by in-situ synthesis compare favorably with those of crystals grown from polycrystalline charges synthe-sized with the high-pressure autoclave or the gradient freeze method.

Empirical evaluation of loss mechanisms in high frequency helix circuits

Abstract: The intrinsic rf losses in each of a series of experimental helix circuits were measured to evaluate loss mechanisms in the helix tape and dielectric support rods. The effects of helix material, helix surface finish, and rod material were measured over the frequency range of 10 GHz to 20 GHz in a test vehicle similar in design to circuits used in I-J band TWTs. The nonresonant perturbation measurement technique permitted separation of conductor losses from dielectric losses while avoiding errors common to other measurement methods. A by-product of the measurement technique was the circuit wavelength used to normalize the loss data.