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.

High energy beam launching apparatus and method

Abstract: Apparatus and method are disclosed for launching a high energy beam of charged particles along an axis into a substantially long path region from an exit aperture, in a manner such that the beam remains confined without application of external focusing fields in the region. The apparatus comprises a cathode, which is a source of electrons to compose the beam, and electrode means for producing an axial accelerating electric field to accelerate electrons in the beam to a relativistic velocity in an accelerating space. At relativistic velocity, the beam itself produces a solenoid-shaped magnetic field which undesirably tends to converge the beam when ionized gas molecules neutralize the space charge in the beam. An external magnet means for producing an axial magnetic field in the accelerating space and a radial magnetic field at the exit aperture, imparts a cyclotron angular momentum to the electrons. The cyclotron angular momentum provides a force to the electrons to substantially cancel the force of the self-magnetic field. Once the beam leaves the accelerating and cyclotron motion inducing space, it remains confined to a desired range of cross section. Such beams may be used for heating plasmas, or in high power microwave oscillators and amplifiers.

Cryosorption surface for a cryopump

Abstract: A two-stage cryosorption pump has a first stage at a higher temperature and a second stage at a lower temperature. Sorption surfaces of reticulated vitreous carbon formed on the second stage have high rigidity and exceptionally high void volume.

Circuit for linearizing the response of an electron capture detector

Abstract: A circuit improvement is disclosed for use in an electron capture detector of the type including an electron capture cell, means for applying polarization pulses to the cell to derive a cell current, means for varying the pulse rate to maintain the cell current constant, and means for converting the pulse frequency to an analog signal indicative of the concentration of an electron-capturing component. Pursuant to the improvement, the pulse rate is varied by means which include an electrometer-amplifier for receiving the cell current and providing an output indicative of cell current departure from a reference current; an integrator for receiving the electrometer-amplifier output, the integrator generating a saw-tooth wave form, the slope of which is proportional to the magnitude of the electrometer-amplifier output signal; means for comparing the integrator output signal with a fixed reference voltage and for generating a triggering pulse when the two are equal; and pulse generator means coupled to the comparator output for generating the polarization pulses in response to the triggering pulses.

Symmetrizing means for RF coils in a microwave cavity

Abstract: A cylindrical ENDOR cavity with RF saddle coils disposed axially is symmetrized by shielding the end portions of the saddle coil within cylindrical conducting rings or cylinder portions whereby the Q of the cavity is substantially enhanced.