Abstract: Apparatus and method for evaporation arc stabilization including a target having a surface of material to be evaporated; circuitry for establishing an arc on the target surface for evaporating the target material, the arc being characterized by the presence of charged particles and a cathode spot which randomly migrates over the target surface; and a confinement ring contacting and surrounding the target surface, the ring being composed of a material such as boron nitride having (a) a secondary emission ratio less than one at the mean energies of the charged particles of the arc and (b) a surface energy less than that of the evaporated target material to thereby confine the cathode spot to the target surface. The confinement ring is employed as a cover for a permeable ring to prevent migration of the cathode spot onto the permeable ring during initial clean-up of the target.

Abstract: Apparatus and method for evaporation arc stabilization including a permeable target having a surface of material to be evaporated; circuitry for establishing an arc on the target surface for evaporating the target material, the arc being characterized by the presence of charged particles and a cathode spot which randomly migrates over the target surface; a confinement ring contacting and surrounding the target surface, the ring being composed of a material such as boron nitride and a permeable ring surrounding the target for effecting substantially uniform evaporation of the permeable target material from the target surface.

Abstract: A thin-film magnetic recording playback head is disclosed wherein mechanically coupled films of a magnetostrictive material and of a piezoelectric material are deposited on a substrate together with a solid state amplifier which is coupled to the piezoelectric film. In operation, localized magnetic patterns on a recording medium induce stress in the magnetostrictive film, which in turn induces in the piezoelectric film a corresponding electrical polarization of non-equilibrium charge density, having a potential associated therewith which is applied to the solid state amplifier.

Abstract: Apparatus and method for evaporation arc stabilization including a target having a surface of material to be evaporated; circuitry for establishing an arc on the target surface for evaporating the target material, the arc being characterized by the presence of charged particles and a cathode spot which randomly migrates over the target surface; and a confinement ring contacting and surrounding the target surface, the ring being composed of a material such as boron nitride having (a) a secondary emission ratio less than one at the mean energies of the charged particles of the arc and (b) a surface energy less than that of the evaporated target material to thereby confine the cathode spot to the target surface. Further, the secondary emission ratio of the confinement ring is preferably less than that of the target.

Abstract: An electroacoustic loudspeaker having a rigid, light-weight diaphragm and a substantially closed loop magnet support of a magnetically permeable material having a channel-shaped cross-section and supported adjacent and spaced from the diaphragm with the open side of the channel facing the diaphragm. The magnet support carries a pair of magnets magnetized and positioned with opposite poles in spaced facing relation and a voice coil is secured to the diaphragm and lies in the gap between the magnets.