Abstract: A flat-plate camera for X-ray diffraction studies of powdered materials under various conditions of temperature. A spindle assembly is provided for rotating a sample specimen about the longitudinal axis of the sample and such that the axis of an X-ray beam striking the specimen, orthogonally intersects the longitudinal axis of the specimen. The spindle assembly includes means for providing a temperature controlled air stream which is directed towards the sample specimen along its longitudinal axis for varying the sample temperature. A flat film plate to be exposed is vertically mounted in back of the sample specimen and is asymmetrically arranged with respect to the X-ray beam. An X-ray shield is provided to permit exposure of sequential segments of the film plate thereby providing direct comparison on one photograph of different exposures taken at various sample temperatures.

Abstract: An optical modulation system and frequency doubler utilizes an organo-substituted carborane cell sandwiched between a pair of crossed polarizers. Light passing through the cell is rotated an amount determined by an electrical control signal applied across the cell. Hence the amount of light passing through the system is modulated by the control signal. When the cell is modulated by an AC control signal, light modulation occurs at twice the AC control signal frequency since the cell has two possible orientations which permit maximum light transfer. The modulated light is directed upon an electro-optical transducer which produces an electrical output proportional to the intensity of the light impinging thereupon.