Abstract: A laminate tile pole piece for an MRI. Each laminate tile has a trapezoidal or annular sector shape. The trapezoidal shape allows the tiles to be attached side by side to form a multiple concentric annular array pole piece without using oddly shaped edge filler tiles needed to fill a circular pole piece with square tiles. The pole piece is made by placing a plurality of tiles into a mold and filling the mold with an adhesive substance to bind the plurality of tiles into a unitary tile body. The unitary tile body is then removed from the mold and attached to a pole piece base to form the pole piece. The mold cavity surface preferably has a non-uniform contour. The bottom surface of the unitary tile body forms a substantially inverse contour of the mold cavity surface contour.

Abstract: A laminate tile pole piece for an MRI, a method and a mold for manufacturing laminate tile metal pole pieces for an MRI. Each laminate tile has a trapezoidal or annular sector shape. The trapezoidal shape allows the tiles to be attached side by side to form a multiple concentric annular array pole piece without using oddly shaped edge filler tiles needed to fill a circular pole piece with square tiles. The pole piece is made by placing a plurality of tiles into a mold and filling the mold with an adhesive substance to bind the plurality of tiles into a unitary tile body. The unitary tile body is then removed from the mold and attached to a pole piece base to form the pole piece. The mold cavity surface preferably has a non-uniform contour. The bottom surface of the unitary tile body forms a substantially inverse contour of the mold cavity surface contour.

Abstract: Disclosed are techniques and apparatus for flexibly mounting a mechanism. The embodiments describe a flexible mount that is at once tolerant of misalignment, shock resistant, insensitive to rotational orientation, compact, and failure resistant. A mechanism is rigidly attached to a retainer that interlocks with a stationary housing and confines and compresses annular resilient members. The methods may in particular apply to the mounting of hydraulic and pneumatic cylinders for actuation of a shutter assembly in an optical system. In addition the techniques can apply to the flexible mounting of other mechanisms incorporating movable members having axes of symmetry, including push rods and rotating shafts.

Abstract: The present invention provides a reliable modular production quality excimer laser capable of producing 10 mJ laser pulses at 2000 Hz with a full width half, maximum bandwidth of about 0.6 pm or less. Replaceable modules include a laser chamber; a pulse power system comprised of three modules; an optical resonator comprised of a line narrowing module and an output coupler module; a wavemeter module, an electrical control module, a cooling water module and a gas control module. Improvements in the laser chamber permitting the higher pulse rates and improved bandwidth performance include a single upstream preionizer tube and a high efficiency chamber. The chamber is designed for operation at lower fluorine concentration. Important improvements have been provided in the pulse power unit to produce faster rise time and improved pulse energy control.

Abstract: A flexible seal permits slidable access to equipment components in an essentially zero clearance environment, without time-consuming disassembly and reassembly. A flexible seal ring includes a thickened radiused boss connected to the outer rim of a flexible flange, connected to a mounting block by an inner hub. The seal ring can be formed as a unitary structure from metal, plastic, elastomer, wood, foam, composite, or combinations thereof. Usually the seal ring has rotational symmetry. Alternatively, the seal ring has an elongated or irregular configuration, e.g. for sealing around a slot. The seal ring can contain an outer o-ring groove. The seal ring is attached to a first plate. A second plate slides laterally to align with the first plate, contacting the flexible seal surface. This presses the seal surface against the second plate, sealing the interface.

Abstract: A gas discharge laser with fast response gas temperature control to maintain laser gas temperature within desired limits during burst mode operation. Preferred embodiments include a passive temperature stabilizer having fins with surface areas exposed to flowing laser gas at least equal to the surface area of the cooling fins of a laser gas heat exchanger. Preferred embodiments utilize heating elements and coolant flow control to regulate laser gas temperatures using processors programmed to anticipate idle periods.

Abstract: Disclosed are techniques and apparatus for flexibly mounting a mechanism. The embodiments describe a flexible mount that is at once tolerant of misalignment, shock resistant, insensitive to rotational orientation, compact, and failure resistant. A mechanism is rigidly attached to a retainer that interlocks with a stationary housing and confines and compresses annular resilient members. The methods may in particular apply to the mounting of hydraulic and pneumatic cylinders for actuation of a shutter assembly in an optical system. In addition the techniques can apply to the flexible mounting of other mechanisms incorporating movable members having axes of symmetry, including push rods and rotating shafts.

Abstract: A superconducting magnet includes a cryocooler coldhead, a sleeve assembly, and a superconducting coil assembly. The sleeve assembly includes a flexible bellows and a sleeve tube and is attached to the superconducting coil assembly so that it may be retracted about one-eighth of an inch breaking thermal contact of the sleeve assembly with the coil assembly's magnet cartridge and thermal shield while remaining hermetically connected to the coil assembly's vacuum enclosure. The coldhead's housing is attached to the sleeve assembly so that the coldhead's first and second stage make unconnected thermal contact with the sleeve assembly. By first retracting the sleeve assembly, the coldhead may be removed therefrom without room temperature air forming an ice ball on the surfaces of the sleeve assembly and without a heat load being transferred to quench the superconducting coil assembly. This permits continuous magnet operation using dual coldheads and dual sleeve assemblies.

Abstract: A superconducting magnet lead assembly for a cryocooler-cooled superconducting magnet having a design current of between generally 50 and 250 amperes. A DBCO (Dysprosium Barium Copper Oxide), YBCO (Yttrium Barium Copper Oxide), or BSCCO (Bismuth Strontium Calcium Copper Oxide) superconducting lead has its ends flexibly, dielectrically, and thermally connected, one end to the generally 30 to 50 Kelvin first stage and the other end to the generally 8 to 30 Kelvin second stage of the cryocooler coldhead. The superconducting lead has a generally constant cross-sectional area along its length. The design current, the lead's length, and the lead's cross-sectional area are chosen such that the design current times the lead's length divided by the lead's cross-sectional area is between generally 720 and 880 amperes per centimeter for a DBCO or YBCO lead and is between generally 180 and 220 amperes per centimeter for a BSCCO lead. The superconducting lead will not itself precipitate a magnet quench (i.e.