Abstract: Apparatus for vacuum pumping an enclosed chamber without the use of activated charcoal to remove hydrogen by cryosorption. As a result, the potential for contamination by a sorbent material is eliminated. The pumping structure includes an integral two-stage vacuum pump. The first-stage pump is a cryogenic pump having a pump chamber and cryoarrays mounted on an expander for cryocondensation of the principal gases present in the vacuum chamber. The second-stage pump operates at room temperatures and includes one or more getter pumps whose principal function is to remove hydrogen molecules that may be present in the vacuum chamber after the first-stage cryopump has removed most of the cryocondensable gases from the vacuum chamber. In one aspect of the invention, the first-stage pump is separated from the second-stage pump by a gate valve to protect the getter pumps during the regeneration flushing of nitrogen through the first-stage cryogenic pump chamber.

Abstract: A microchannel plate (MCP) apparatus and method in which the output metalization layer or electrode is covered with a thin coating to reduce the number of spurious electron emissions striking the phosphor screen or other collection anode in an image intensifier. Microchannel plates manufactured in this way have the beneficial effect of improving yield in the manufacture of night vision devices.

Abstract: The invention is a transportable and reconfigurable system and method designed for on-site conversion of toxic substances to nontoxic forms. The invention includes an electron beam generator, a reaction chamber and effluent post-processing modules mounted on a carrier for transporting the system from site to site.

Abstract: A focused electron-bombarded (FEB) ion detector comprising an MCP, focusing means, and a collection anode disposed in a detector body. The collection anode includes a diode for receiving the focused output electron beam from the MCP. The gain between the input ion current to the MCP and the detector output signal from the diode is on the order of 1-100 million, depending on the device configuration and applied biasing voltages.

Abstract: An electron beam therapy system and a facility for using an electron beam therapy system. In the preferred embodiment, the electron beam therapy system comprises a linear accelerator, microwave source, and associated electronics disposed in a housing. The housing is mounted on a positioning means such as a C-arm to direct the electron beam to the desired site on the patient. The entire housing and positioning means is mobile and may be moved to different locations in the facility. Connectors are provided at the different locations in the facility to connect the electron beam source to a central power source within the facility.

Abstract: What is disclosed is a novel toxic waste remediation system designed to provide on-site destruction of a wide variety of hazardous organic volatile hydrocarbons, including but not limited to halogenated and aromatic hydrocarbons in the vapor phase. This invention utilizes a detoxification plenum and radiation treatment which transforms hazardous organic compounds into non-hazardous substances.

Abstract: Cryopump apparatus and method for controlling the operating temperature of a cryoarray in a cryopump. The cryopump has means for thermally isolating one of more of the cryoarrays from the refrigeration source. The means for thermally isolating is a thermal switch formed from at least first and second switch elements made of materials having dissimilar coefficients of thermal expansion. The thermal switch is also used in isolating one of the pump's cryoarrays during a partial regeneration process. The thermal switch of the preferred embodiment may also be used to prevent one of the pump's cryoarrays from falling below a predetermined operating temperature.

Abstract: A method and apparatus are disclosed using a combination of convection and conduction cooling to cool an article in an evacuated environment. A processing chamber is used which includes at least one heat sink. A flat surface of the article to be cooled is positioned within the chamber in a spaced apart facing parallel relationship to a facing surface of the heat sink. High conductivity gases are admitted into the chamber to accomplish cooling of the article.

Abstract: A high-electron mobility transistor or HEMT has a top surface layer between its gate and drain arranged to produce a channel to drain conductance that is close to the ungated channel conductance to lower the output conductance and reduce gate leakage and gate capacitance. The transistor has a high band-gap active layer to produce a 2DEG channel in an adjacent layer, and source, gate and drain electrodes on the active layer. An undoped or lightly doped surface layer in the region between the gate and the drain produces a low conductance for a region of a few hundred .ANG. from the drain-side edge of the gate. This spreads the electric field domain over at least this few hundred .ANG. distance.

Abstract: A low noise microchannel plate limiting feedback includes a conductive deposit on an output side for reducing open areas at an output end of the plate. The microchannel plate can be included in an image intensifier tube.

Abstract: An effusion source, for the generation of molecular beams, adapted to be positioned at an angle to the horizontal, within a vacuum chamber, of an MBE system including heating structures around the source to create uniform temperatures across the source in planes substantially parallel to the horizontal to cause uniform temperatures in planes substantially parallel to the horizontal in materials placed within the source and intended for MBE applications. A number of heating embodiments are described.

Abstract: Apparatus for vacuum pumping an enclosed chamber includes a cryopump in gas communication with the chamber for removing gases by cryocondensation and cryotrapping and an auxiliary pumping device for removing gases that are difficult to remove by cryocondensation or cryotrapping. The cryopump does not contain a sorbent material for cryosorption. As a result, the potential for contamination by a sorbent material is eliminated. The auxiliary pumping device can comprise an ion pump or a turbomolecular vacuum pump. When an ion pump is used, the ion pump is inactivated during periods of high gas loading in the chamber. The vacuum pumping apparatus is particularly useful for vacuum pumping of a plasma vapor deposition chamber.

Abstract: A system for handling and processing thin substrates, such as substrates for magnetic disks. The system includes a main chamber, entrance and output load locks, a buffer chamber, substrate load/unload mechanism, and a plurality of substrate processing stations positioned contiguous with the main vacuum chamber. The system further includes a transport for moving a plurality of cassettes carrying vertically oriented substrates into the entrance load lock, to the buffer chamber where the substrates are transferred into the main chamber, and to the output load lock where processed substrates are placed back in the cassettes. The substrates are transferred to and from the cassettes to and from the substrate load/unload mechanism by means of dedicated lift blades. The system further employs a simple three-step transfer of the substrates from processing station to processing station which greatly increases the throughput potential compared to prior art systems which rely on complex substrate handling and transfer.

Abstract: A method and apparatus are disclosed using a combination of convection and conduction cooling to cool an article in an evacuated environment. A processing chamber is used which includes at least one heat sink. A flat surface of the article to be cooled is positioned within the chamber in a spaced apart facing parallel relationship to a facing surface of the heat sink. High conductivity gases are admitted into the chamber to accomplish cooling of the article.

Abstract: Sputter coating source in which the target is mounted directly on the front side of the cathode and coolant is circulated on the back side of the cathode. The coolant does not contact the target, and the target is clamped tightly to the cathode by retainers which permit it to be removed and replaced easily without leakage of coolant.

Abstract: A matrix modifier of finely-divided metallic palladium dispersed to contact a metal constituent to improve analysis of the constituent during graphite furnace atomic absorption spectroscopy. The palladium interacts with a variety of metals in a sample to increase the vaporization temperatures of the metals. One way of contacting palladium with the metal analyte is to introduce it as a salt in solution with the sample into the graphite furnace along with a surfactant. A finely-divided metallic palladium having high surface area is produced in the furnace by introduction of hydrogen gas, which acts as a reducing agent, to reduce and maintain palladium in its metallic form at an early point in the temperature program, prior to evaporation of the surfactant.

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: A device for releaseably holding a workpiece includes a resilient collet which is attached to a base by an elastomeric member. Typically, the collet is an annular ring. Several fingers for holding the workpiece extend from the collet. The fingers are pivoted by actuating a member which elastically deforms the collet and causes the fingers to pivot from a position for engaging the workpiece to a position for releasing the workpiece and vice-versa. In one application, the base is a platen for supporting a wafer in a semiconductor processing system, and a plurality of the holding devices are arranged around the periphery of a rotating disk. A counterweight ring is attached to the collet to counterbalance the moment generated by the centrifugal force of the wafer pressing against the fingers as the disk is rotated.

Abstract: A double-tuned circuit is realized from 1/2.lambda..sub.1 transmission lines for connecting a pair of inductors in series at a first frequency and in parallel for a second frequency where said first and second frequencies are in the ratio of a power of two.

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.