A Gold-Silicon Surface-Barrier Proton Range Telescope

Of interest in cosmic-ray studies is the proton energy spectrum. The recent development of the Au-Si semiconductor particle detector affords a convenient means for studying the proton spectrum for low energies. The small size, stability, energy resolution, and relative insensitivity to ß- and γ-radiation of these diodes suggest their usefulness as proton detectors on space vehicles. Gold-silicon detectors are presently being made at the Laboratories for Applied Sciences of The University of Chicago using the fabrication technique developed at the Oak Ridge National Laboratory. An apparatus is described which employs two detectors forming a proton range telescope. This has been made possible by fabricating silicon wafers as thin as 0.004 inch. This apparatus provides information concerning the proton flux lying in the energy intervals from ≈ 0.5 to 5 mev and 5 to 10 mev, without the use of pulse-height analysis. This principle can be extended to additional energy intervals.