Diode Array Camera Tubes and X-Ray Imaging

The silicon diode array camera tube, developed for Picturephone® visual telephone service applications, 1 has proved to be a versatile device. The possibility of using the diode array target for X-ray imaging had been discussed on various occasions, but a particularly useful step was the realization by E. I. Gordon that, since each X-ray photon could produce a great number of hole-electron pairs, very high quantum efficiency might be expected in this application. 2 Sub345 346 T H E BELL SYSTEM TECHNICAL JOURNAL, FEBRUARY 19G9 sequent measurements bore out this expectation. 3 ' 4 There are many uses for a practical imaging device with high visual brightness, ranging from medical and biological research applications to productionline testing of silicon wafer crystal orientation. 6 This paper describes the modification of the camera tube for X-ray imaging and measurements of spectral response obtained with such a tube. The relevant features of all the various X-ray imaging techniques are compared in the context of specific applications to identify the particular devices which are most suitable for specific purposes. This permits a balanced evaluation of the usefulness of the silicon diode array camera tube for X-ray imaging, as well as shedding light upon other possible imaging systems.