Abstract: The present invention comprises cyclotron display devices similar to cathode ray tubes (CRTs) in which the CRT electron gun is replaced by one or more cyclotrons that produce electrons using lower voltages and energy costs than a CRT electron gun does. This can be done both with monochrome and color displays, as disclosed. In addition, the electrons emerge from the cyclotron with adequate velocity, thus obviating the need for accelerating electrodes. The need for electron focusing is also greatly reduced, or eliminated, since the electrons emerge from the cyclotrons as beams, rather than as diffuse clouds. The cyclotron display assembly can be made to be significantly shorter than the conventional electron gun CRT. In addition, an array of cyclotrons, rather than just a single one, can be used, so that each cyclotron maps to a fractional portion of the video screen. This further shortens the length of the cyclotron display.

Abstract: Methods for preparing homogeneous magnetic fluid compositions capable of forming ordered one dimensional structures or two dimensional lattices in response to externally applied magnetic fields are disclosed. The compositions are prepared using improved co-precipitation methods in which the steps of the procedure have been tuned to reduce sample heterogeneity. Fe.sub.3 O.sub.4 particles are coated with a surfactant and dispersed in a continuous carrier phase to form a homogeneous magnetic fluid composition. The ability of the composition to generate ordered structures can be tested by holding a magnet near a thin film of the compositions and observing the formation of colors in the region near the magnet. Methods for controlling the characteristic spacing of the ordered structures formed by the composition are also disclosed.