Abstract: A superconducting magnetic resonance imaging magnet assembly is provided. The assembly includes an axial imaging bore to receive patients and a coil housing surrounding the axial bore. A main magnet coil assembly is disposed within the housing. The main magnet coil assembly includes a plurality of main magnet coils to produce a magnetic field. At least three pairs of superconductive coils are provided. In one aspect, each of the coils in at least one of the pairs comprises a superconductor wire carrying an electric current in a direction opposite to the direction of current carried by the coils of another of the superconductive pairs. The superconductor wire comprises a superconductor core and a stabilizer having a channel. The wire is wound so that the channel has a radially outward facing opening.

Abstract: The invention relates to the design of laser collimators for free space through-the-air optical links. The laser collimator provides means for expanding the diameter of a light beam emitted from the end of a monomode optical fiber that has been optical coupled to a semiconductor laser diode and projecting through free space the expanded beam as a low divergence beam of substantially parallel rays. The laser collimators disclosed are compact, simple to make, and overcome many of the deleterious effects that result from the requirement that the air-glass surface terminating the end of the monomode fiber coupled to the semiconductor laser is not normal to the axis of the optical fiber. Means are also disclosed for increasing the divergence of the cone of light emitted from the tip of an optical fiber thereby enabling the construction of laser collimators with larger expansion ratios in a compact size.