Abstract: A high voltage switch tube with a central cathode cylindrically symmetric to and surrounded by a tubular anode, with a grid interposed between the cathode and anode. A high negative voltage is applied to the cathode, but the flow of electrons to the anode is blocked by the grid which is held near cathode potential. After a space charge is created at the grid by electrons from the cathode, the grid is pulsed to ground potential, releasing electrons from the cathode to yield a very high current pulse. The cathode is preferably a graphite foam sleeve mounted on a support structure.

Abstract: An X-ray source with a cathode formed as a cylindrical electrode having a hollow central anode tube on its axis, with a grid surrounding the anode and interposed between the anode and cathode. The central anode tube is hollow and filled with a working medium. A high negative voltage is applied to the cathode, but the flow of electrons to the anode is blocked by the grid which is held near cathode potential. After a space charge is created at the grid by electrons from the cathode, a very short pulse to ground is applied to one end of the grid, yielding a relativistic wave of potential which propagates along the axial length of the grid. This wave of potential releases the electrons from the cathode, which flow directly to the anode. The impingement of the electrons on the tubular anode produces X-rays from the interior surface of the anode tube.

Abstract: A pre-excited excimer laser is formed in a thin flat package. Input X-ray photons which are modulated by passing through a body to be analyzed raise the pre-excited excimer gas molecules to a lasing energy level and the coherent radiation produced is measured and produces an amplified image of the input X-ray photon modulation.

Abstract: An X-ray tube has a wide area cold cathode with a graphite felt surface which faces and is spaced from a wide area anode of high atomic number material. A grid is interposed between the two and the anode, grid and cathode are enclosed in an envelope which is filled with gas at a low pressure. The graphite surface of the cathode is connected to a relatively high negative potential so that electrons are emitted from the entire surface area and impinge upon the anode, after triggering by the grid. The distribution of the energy of photons emitted from the anode is relatively constant during the ignition period of the tube. An extremely wide area X-ray source is then defined having constant bremstrahlung content which enables good gray scale measurements when employing the X-ray source. A pinhole collimator disposed externally of the tube ensures collimation of the output X-ray field.

Abstract: Objects to be examined, such as tissue or any cellular or crystalline material, e.g. semiconductor wafers, are placed in a region of confluence of two interfering coherent beams of radiation which are at the same frequency and phase and at a frequency to which the object is semi-transparent. The beams are produced by separate sources or by refraction by a Fresnel biprism or any other interferometer structure. An off-axis parabolic reflection system is also disclosed. The interference fringe phase and amplitude perturbation produced by the object is detected and examined to derive information regarding physical properties of the object or abnormalities in its structure. Such abnormalities, as fractures or latent stresses in a semi-conductor wafer or the presence of tumors in biological tissue can be determined.

Abstract: An optical processing system based on noncoherent light processing employs both geometrical and diffraction optical systems. One portion of the optical system performs a subtraction operation of the image from itself where one of the subtracted images is relatively defocused and one is delayed in time from the other. The subtracted image is edge-enhanced and then applied to a spatial filter employing an interferometer in which spatial filters are contained in the interferometer iris plates. Additional spatial filtering is performed on the interference image and the processed image is displayed in an appropriate display which can selectively view the processed image, the unprocessed image or combinations of the two. Light storage elements are employed for storing the processed images in appropriate buffers over a given length of time. The buffers are read out by a flashlamp. Suitable shutters are closed during the readout process.