Abstract: An energy efficient data center incorporating superconducting power transmission cables coupled with cryogenically cooled semiconductor inverters and converters, used to supply power to cryogenically operated or room-temperature computers and servers. Other options and features include a lighting system whose performance is enhanced by the cold temperatures, fiber optic connections operated at cryogenic temperatures, integrated renewable energy power sources, advanced energy storage technologies, cryogenically operated computers, and a number of other cryogenic hardware. The operating temperature of the cryogenic components can be anywhere in the range between 0 K and 200 K, with other components operating above 200 K.

Abstract: An energy efficient data center incorporating superconducting power transmission cables coupled with cryogenically cooled semiconductor inverters and converters, used to supply power to cryogenically operated or room-temperature computers and servers. Other options and features include a lighting system whose performance is enhanced by the cold temperatures, fiber optic connections operated at cryogenic temperatures, integrated renewable energy power sources, advanced energy storage technologies, cryogenically operated computers, and a number of other cryogenic hardware. The operating temperature of the cryogenic components can be anywhere in the range between 0 K and 200 K, with other components operating above 200 K.

Abstract: A bi-directional power converter for cryogenic operation based on a bi-directional cryo-MOSFET switch. Cryogenic power electronics lends itself easily to bi-directional topologies, and brings higher efficiencies, further reductions in switching speed, higher-frequency operation, reduction in size and weight of associated transformers and inductors, and reductions in overall size and weight. In addition, cryogenic power electronics operating around liquid nitrogen temperatures is easily integrated with superconducting motors, motor drives, and transformers, all of which can reduce size and weight of shipboard power systems, allowing for greater payload.

Abstract: An ultra compact ring topology puts the output terminals of solid state switches physically at the center of a circuit with the switches surrounded by voltage busses. The switches are symmetrically arranged around the output bus, the voltage busses are filtered (decoupled) to ground using symmetrically positioned filter components, and lead lengths to and from the switches are minimized. Switch driver circuits are closely integrated with each switch and positioned as close as possible, each to its associated switch, and arranged symmetrically. Switches may be at cryogenic temperatures and busses and lead connectors may be superconductive.

Abstract: This invention describes a means by which lasers and laser beam controllers mounted on moving vehicles or other unstable platforms can be isolated from vibrations. By magnetically levitating the entire laser or just the beam controller hardware, targeting efficiency can be vastly improved. Superconducting levitation and control coils can be used to reduce added power losses. Cryogenic power conversion systems can be employed to drive the levitation system. The laser could also be cryogenically cooled, depending on the type of laser employed.

Abstract: This invention describes a means by which performance characteristics of capacitors can be improved. This is achieved by reducing the temperature, preferably but not exclusively to cryogenic temperatures below 100 K. The dielectric strength, dielectric losses, equivalent series resistance, and plate losses in many capacitors, such as film capacitors, improve as the temperature is decreased. Current carrying capacity is improved. A capacitor bank exhibits energy densities up to four times those of conventional, room-temperature capacitor banks. Cryogenic capacitors can be combined with cryogenically operated semiconductors or with superconductors to reduce the size, weight, and losses of a complete system.

Abstract: An electrical switching topology for a hybrid switch provides extremely low losses in both cryogenic and non-cryogenic electronic systems. In this switch having switch modules connected in parallel, switching losses in a first module are separated from conduction losses in the parallel-connected second module. The conduction losses are then further reduced by cryogenically cooling the second module. Since the switching losses of the first module can be absorbed outside a cryogenic container, the switching losses do not add to the cryogenic heat load. In other applications, the switching module operates at lower temperatures to provide higher switching speeds and reduces switching heat generation.

Abstract: A detachable superconducting lead includes a vacuum-sealed thermal transition through which a stabilized conductor passes. Two identical leads are attached and surrounded by a sealed Dewar and allowed to cool either naturally or by way of a cooling element. Detaching the leads requires the joint to be heated up by a heat transfer unit or by a heat gun after the Dewar is removed. Once warmed, the lead can be disassembled with tooling appropriate to the joint. In many instances, regular fasteners can be used. Removable Dewars may be constructed with insulation (including vacuum) using O-rings and flanges.

Abstract: Switching losses and conduction losses are isolated by networks which are partially cryogenic and partially at room temperature. Switching losses are independent of temperature. Advantageously the switching losses are taken in a snubber network at room temperature and conduction losses are incurred at cryogenic temperatures, where majority carrier devices like MOSFETs operate with ultra low on-state resistance and corresponding low conduction losses. Low loss leads carry current efficiently from the cryogenic environment to room temperature without adversely affecting refrigeration. Switch and snubber network may both operate cryogenically.

Abstract: The highest-power switches now available are based on thyristor-type devices: GTOs (Gate turn-off thyristors), MTOs (MOS controlled turn-off thyristors), IGCTs (Integrated gate commutated thyristors), and the new ETOs (Emitter turn-off thyristors). These devices handle kilovolts and kiloamperes for megawatt inverters/converters. Measurements by the inventors show that conduction losses of MOSFETs and switching losses of IGCTs are drastically decreased by cryo-cooling. IGCTs, ETOs, and MTOs, together with many small, low voltage MOSFETs for gate and emitter turn-off circuitry, are cryo-cooled to attain much higher switching speeds and a reduction in size, weight and cost of high-power (megawatt range) equipment.

Abstract: A method and apparatus for reducing conductive thermal losses in high-current cryogenic power electronics systems needing large cables to interface between warm and cold environments. Thermal losses increase with increasing cross-sectional area. The total current at the warm/cold interface is split into many smaller currents by splitting the power buss into a plurality of parallel leads. Respective physical switches in each smaller lead at the interface interrupt current flow, and at the same time open the path for thermal conduction along the lead. When little or no current is flowing through the system, selected smaller leads of the power buss are physically opened by the associated switches to stop the thermal and electrical flow along these leads. Current diverts to another parallel lead in the buss but the cross section for heat flow is reduced at the interface.

Abstract: This invention describes a means by which performance characteristics of capacitors can be improved. This is achieved by reducing the temperature, preferably but not exclusively to cryogenic temperatures below 100 K. This is based on the observation that the dielectric strength, dielectric losses and plate losses in many capacitors, such as film capacitors, improve as the temperature is decreased. A cryogenic capacitor bank is also described, which exhibits energy densities up to four times those of conventional, room-temperature capacitor banks. Cryogenic capacitors can be combined with cryogenically operated semiconductors or with superconductors in such a way as to reduce the size, weight, and losses of a complete system.

Abstract: Losses are reduced in electrical conductors and filters, especially those made with superconducting cables or inductors, which carry currents having both direct current (DC) and alternating current (AC) portions as in rectifier busses and power distribution systems. Superconducting cables and chokes are capable of passing direct current with practically zero losses, but they exhibit considerable AC losses. A low impedance AC bypass of the superconducting cables and chokes minimizes these losses.

Abstract: Magnetic resonance force microscopy (MRFM) is a technology capable of detecting the magnetic resonance of a small number of spins and, potentially, a single spin of an electron or nucleus. Most methods use soft cantilevers with microscopic dimensions (microns) which have been developed for atomic force microscopy. Cantilevers have been both a solution and problem of high sensitivity force detection. They are difficult to fabricate and it is difficult to achieve the right sensitivity and stiffness with them. The proposed invention eliminates the cantilever and replaces it with small, magnetically sensitive objects called birdies, which are manipulated above a sample using electromagnetic field control. The basic principles of the cantilever-free MRFM are the same as those of traditional, cantilever-based systems. Motion of the birdie induced by magnetic resonance is monitored using optical interferometry.

Abstract: Magnetic resonance force microscopy (MRFM) is a technology capable of detecting the magnetic resonance of a small number of spins and, potentially, a single spin of an electron or nucleus. Most methods use soft cantilevers with microscopic dimensions (microns) which have been developed for atomic force microscopy. Cantilevers have been both a solution and problem of high sensitivity force detection. They are difficult to fabricate and it is difficult to achieve the right sensitivity and stiffness with them. The proposed invention eliminates the cantilever and replaces it with small, magnetically sensitive objects called birdies, which are manipulated above a sample using electromagnetic field control. The basic principles of the cantilever-free MRFM are the same as those of traditional, cantilever-based systems. Motion of the birdie induced by magnetic resonance is monitored using optical interferometry.

Abstract: Increasing RF transmission power, retuning the RF transmitter and receiver coils, and increasing RF reception gain, enable MR inspection of product in a container that presents a substantial portion of an electrically conductive barrier in transverse orientation to the exciting RF magnetic field.

Abstract: In a high field superconducting magnet device, e.g., for NMR, a conventional low temperature superconducting solenoid type magnet is combined with an inserted superconducting magnet, which is fabricated from high temperature superconducting materials having very high critical currents. Both magnets operate with stability at the same low temperature in persistent modes after operating conditions are achieved. The flux field and superconducting currents in the inserted superconducting magnet are generated by flux trapping when the field of the low temperature superconducting solenoid type magnet is reduced. The field of the hybrid magnet assembly is the resultant of the respective fields of the two magnets.

Abstract: In a high field superconducting magnet device, e.g., for NMR, a conventional low temperature superconducting solenoid type magnet is combined with an inserted superconducting magnet, which is fabricated from high temperature superconducting materials having very high critical currents. Both magnets operate with stability at the same low temperature in persistent modes after operating conditions are achieved. The flux field and superconducting currents in the inserted superconducting magnet are generated by flux trapping when the field of the low temperature superconducting solenoid type magnet is reduced. The field of the hybrid magnet assembly is the resultant of the respective fields of the two magnets.

Abstract: A magnetic suspension system and a procedure for operating the system employ a superconducting magnet having a lift coil assembly for developing a magnetic field to interact with the magnetic field of an object to be supported about the superconducting magnet. Smaller and larger magnet coils are provided in the superconducting magnet with counter rotating flow of current to introduce a depression in a potential energy surface above the superconducting magnet, this allowing the object to seek a height at the depression for stably locating the object. The system and methodology employs a set of control coils which are energized to orient and to translate the object to maintain a desired position and orientation. Pairs of the control coils are energized to produce a tilting of the object, as in roll or pitch, or a displacement of the object relative to the vertical axis.

Abstract: Mixtures comprising semicarbazide/urethane reaction products of 4-amino-1,2,4-triazole, an aliphatic polyisocyanate and a reduced sugar or glycerol are particularly suited for protecting films, fibers, spandex and other polyurethane articles against discoloration due to exposure to fumes, light and heat.