Abstract: An improved electroinjection method of introducing a sample having positive and negative ions into a capillary column for CE or CZE process by introducing a short plug of a low concentration buffer before introducing the sample into the column which results in increasing amount of charged ions of the sample introduced in the capillary column due to increasing the electric field at the injection point. A method for efficiently introducing both positive and negative ions is also shown.

Abstract: Information on radiation dosage from segmented ionization chambers can be incomplete due to the existence of insensitive regions of the chamber. By measuring the total current to the high voltage power supply, the total ionization current including that in the insensitive areas can be estimated, thereby providing a measure of the dosage to the insensitive areas.

Abstract: An improved transferred electron III-V semiconductor photocathode comprising an aluminum contact pad and an aluminum grid structure that improves quantum efficiency by removing a major obstacle to electrons escaping into the vacuum and controls dark spot blooming caused by overly bright photon emission sources.

Abstract: Semiconductor wafers having patterns of steps and grooves defining microcircuit elements thereon are coated with metallic film by supporting the wafers individually adjacent a respective ring-shaped sputtering source in stationary relationship thereto. To effectuate such individual wafer processing on a continuous basis and preserve the evacuated argon environment, a vacuum chamber sputter coating apparatus is provided which has a number of work stations therein, at least one of which includes said ring-shaped sputtering source. Also included is a load lock; and an intermittently rotating vertical plate-like wafer carrier means therewithin positioned closely adjacent the chamber entrance, and carrying wafers in turn from the load lock to the work stations. The carrier includes apertures each accepting a wafer therewithin in an upright position, with the wafers edgewise resiliently supported by clip means, without the use of any externally-originating supports such as platens.

Abstract: The collector in a linear-beam electron tube is insulated from its heat sink so that it can be operated at a depressed potential. The insulation comprises two bands of dielectric sequentially in contact between the collector and heat sink. The intervening space is sealed off and preferably filled with a dielectric fluid to improve heat transfer and inhibit voltage breakdown. Gaps in one band are preferably aligned with solid parts of the other to reduce electric leakage.

Abstract: In order to bring a high power vacuum tube to full power in a few seconds, it is necessary to heat the cathode quickly to 1100.degree. C. In large tubes, prior art structures cannot be simply enlarged. A novel cathode structure in which the heater element is anisotropic pyrolytic graphite coated with anisotropic pyrolytic boron nitride for insulation and then sintered to the cathode avoids these problems.

Abstract: In a gyrotron cavity resonator, generated energy is extracted into a symmetric set of fundamental-mode waveguides by ports disposed to couple energy in phase from the operating electromagnetic mode but in anti-phase with respect to an unwanted mode of lower cutoff frequency than the operating mode, thereby neutralizing coupling to the unwanted mode. A second set of interspersed ports may be disposed to load degenerate, orthogonal modes.

Abstract: Pre- and post-processing of a semiconductor wafer within a main vacuum chamber is accomplished by a wafer holder disposed within a clam shell-like device. The clam shell device includes a first member disposed above the wafer holder and a second member disposed below the wafer holder in a facing relationship to the first member. The first member and the second member each have a respective mating surface. The first member and the second member are movable between a closed position wherein the mating surface of each of the first member and second member hermetically engage each other in an open position. The clam shell device forms an interior chamber when in its closed position. Gases are evacuated from the interior chamber, exteriorally of the main chamber, when the clam shell device is in in a closed position to avoid contamination of the vacuum environment.

Abstract: A magnetron sputtering apparatus includes a rotatable magnet. At least a portion of the centerline of the magnet lies on a curve defined by ##EQU1## where .xi.(u) is a preselected erosion profile. When stationary, the magnet generates a localized magnetic field of approximately constant width. In operation, when the magnet is rotated, it generates the preselected erosion profile in the target. The preselected erosion profile may be constant.

Abstract: A very fine-mesh, non-emissive shadow grid is formed on the smooth emissive surface 16 of a thermionic cathode 12 by deposition from a vapor a continuous layer 22 of non-emissive conductive material. Between the elements 24 of the grid the non-emissive material is removed by bombardment through an apertured mask to restore emissivity between the elevated grid elements 24.

Abstract: A compact, small diameter, standing-wave linear accelerator structure suitable for industrial and medical applications is disclosed. The novel structure utilizes a new type of coupling cavity for Pi/2 mode, standing-wave operation. The coupling cavity fits into the webs between the accelerating cavities substantially within the diameter of the acclerating cavities. This is made possible by keeping the center section of the cavity thin to concentrate the electric field vector at the center of a section of the cavity and by enlarging the ends of a section of the coupling cavity to accommodate the magnetic field vector. This structure offers a significant reduction in overall diameter over the side-coupled, annular ring, and existing coaxial coupled structures, while maintaining a high shunt impedance and large nearest neighbor coupling (high group velocity). A prototype 4 MeV, 36 cm long, S-band accelerator incorporating the new structure has been built and tested.

Abstract: A radiation therapy unit with a beam of rays propagating from a focal point along a beam axis comprises a radiator head arranged on the beam axis with a double-focus multi-leaf collimator. The multi-leaf collimator exhibits a plurality of adjacently arranged diaphragm plates which in each case have two side faces, two front faces and an inside and an outside face. Each side face of each diaphragm plate forms a part of a surface area of a cone, all such cones having both a common cone axis which extends perpendicularly to the beam axis through the focal point, and a common cone point which coincides with the focal point. Means are provided for guiding the diaphragm plates so that each diaphragm plate performs a pure rotation about the cone axis during its displacement.