Oriented Graphite X-Ray Diffraction Telescope

A development program performed during the last year under a contract with the Office of Naval Research has indicated that diffraction focusing of X-rays may offer significant detection advantages when used to focus low energy gamma and X-radiation onto single detectors. The work which supports this conclusion includes a survey of diffraction crystalline materials, diffractometer X-ray measurements of selected crystal specimens, conceptual design studies of X-ray focusing systems, and finally, the fabrication and testing with a radioactive source of a small parabolic focusing array of highly oriented pyrolytic graphite flat crystals.1 The high diffraction efficiency of oriented graphite even to energies beyond 60 keV has encouraged the development of complete prototype focusing systems. As a part of this continuing effort an eighteen shell oriented graphite laboratory focuser is currently being developed. In order to supply the thousands of square inches of graphite required for this work, a facility has been assembled within General Electric Nuclear Systems Operation at Evendale, Ohio, to produce highly oriented pyrolytic graphite economically and in large quantities.