Abstract: A detector in a residual gas analyzer (RGA) is configured to receive ions traveling in a downstream direction along a beamline and includes a steering electrode offset from the beamline. A first ion-receiving electrode is at least partly on the opposite side of the steering electrode from the beamline. A second ion-receiving electrode is at least partly offset from the beamline, at least partly across the beamline from at least a portion of the steering electrode, and at least partially upstream of at least a portion of the steering electrode. A shielding electrode is arranged at least partly between the beamline and the second ion-receiving electrode. A source applies a potential to the shielding electrode. A residual gas analyzer (RGA) includes an ion source, an analyzer, and such a detector.

Abstract: A detector in a residual gas analyzer (RGA) is configured to receive ions traveling in a downstream direction along a beamline and includes a steering electrode offset from the beamline. A first ion-receiving electrode is at least partly on the opposite side of the steering electrode from the beamline. A second ion-receiving electrode is at least partly offset from the beamline, at least partly across the beamline from at least a portion of the steering electrode, and at least partially upstream of at least a portion of the steering electrode. A shielding electrode is arranged at least partly between the beamline and the second ion-receiving electrode. A source applies a potential to the shielding electrode. A residual gas analyzer (RGA) includes an ion source, an analyzer, and such a detector.

Abstract: A boat alignment device including a clamp for attachment, to a support and a block pivotally attached to the clamp. The block is provided with an aperture of elliptical cross section. A telescoping arm has an outer tubular member of elliptical cross section snugly, yet slidably positioned within the aperture in the block. The telescoping arm also has an inner tubular member of elliptical cross section nested within the outer member and capable of being withdrawn therefrom.