Instrument for Lunar Surface Chemical Analysis

Abstract

An instrument has been designed and constructed which utilizes the interactions of monoenergetic alpha particles with matter for surface chemical analysis. The source of alpha particles is a radioactive nuclide, such as 242Cm. The energy spectra of backscattered alpha particles are measured with semiconductor detectors. Other detectors (with gold foils over them to eliminate alpha particles) register protons from α,p reactions. Transistorized electronics provide 128-channel pulse height analyzers for both alpha and proton spectra. The first prototype instrument designed for the presently planned Surveyor Lunar Missions weighs less than 4 kg and uses less than 1.3 W.