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.

Method of mapping ion implant dose uniformity

Abstract: A method of mapping implanted ion dose uniformity is disclosed in which wafers of polysilicon-on-silicon or polysilicon-on-oxidized-silicon are implanted with the ion dose to be mapped and then scanned in a spectrophotmeter using monochromatic radiation An interference spectral technique is used to achieve improved sensitivity while preserving thermal and electrical properties close to those of actual devices

A method of space charge control in an ion trap mass spectrometer

Abstract: A method of using a quadrupole ion trap mass spectrometer (10) for high resolution mass spectroscopy is disclosed. In the preferred embodiment, the space charge in the ion trap is controlled with high accuracy. The mass spectrum to be analyzed is divided into a plurality of contiguous segments (s1, s2, s3...) and each of the segments is separately scanned. To control space charge, a broadband supplemental waveform (Vs) is applied to the ion trap (1) during the ionization period (Ts1, Ts2, Ts3...) for each segment, the broadband signal being constructed to eliminate all unwanted ions from the ion trap by resonance ejection such that only those ions having masses within the desired mass segment remain in the trap. Preferably, the ionization of each mass segment is performed under identical trapping conditions, and the ionization parameters for each segment is adjusted to optimize the space charge in the trap for that particular segment. Conveniently, the adjustment of ionization parameters may be based on the previous analytical scan of the same mass segment.

Spectroscopic plasma torch for microwave induced plasmas

Abstract: A spectroscopic plasma torch suitable for use at atmospheric pressure disclosed. The torch utilizes a microwave induced helium plasma confined in a plasma discharge tube. The plasma is suspended and stabilized by a vortex flow of helium. The torch includes a high velocity gas jet for introducing sample materials into the plasma The design avoids the formation of carbon deposits in the plasma discharge tube caused by the premature pyrolysis of organic materials outside the plasma and prevents other sample materials from being adsorbed on the surface of the plasma tube. Because of these characteristics, the torch is particularly well suited for use as a component in a gas chromatography detector which employs helium as the plasma support gas.