Abstract: A rotor assembly includes a substantially cylindrical support structure having at least one first region, and at least one second region. At least one rotor coil is positioned within each first region of the substantially cylindrical support structure. Each rotor coil includes a pair of distal end portions and a convex center portion, and the average mechanical density of the convex center portion is substantially equal to the average mechanical density of the distal end portions. The average mechanical density of the at least one first region is substantially equal to the average mechanical density of the at least one second region.

Abstract: Highly efficient reflective optical system that perfectly reflects incident electromagnetic radiation of a certain spectra and almost perfectly reflects radiation of another spectra. Incident electromagnetic radiation having a wavelength above a critical wavelength is relatively perfectly reflected. The critical wavelength is determined by the critical temperature of a high temperature superconductor material incorporated in the optical system. A preferred embodiment includes a cryogenically cooled substrate to which is applied a coating of a noble metal such as silver. A layer of a high temperature superconductor material is applied over the coating of noble metal. Since the critical wavelength of the incident radiation is inversely proportional to the critical temperature of the superconducting material, the use of high temperature superconductor material in the optical system provides a critical wavelength whereby certain spectra of an incident radiation is perfectly reflected.