Optical Ranicon detectors for photon counting imaging. I

We discuss the design and development of Ranicon detectors for optical photon counting imaging on ground‐based telescopes. The significant factors which determine the performance of these detectors are found to be the proximity focusing stage, the microchannel‐plate stack (MCP), and the signal processing electronics. For applications in optical astronomy, the low photon counting efficiency typically found with optical MCP‐based detectors, due to ion barrier films, presents an additional consideration. We review the performance of each stage of the Ranicon detector and the techniques for achieving optimal performance. A new approach to the signal processing electronics reduces nonlinearity, while achieving increased processing speeds and a position error corresponding to <21 μm FWHM. A significant improvement in detector performance is achieved with an advanced Ranicon incorporating a reduced proximity focusing gap and an unfilmed input plate in the MCP stack. The theoretical spatial resolution of both sta...