The MISO low energy γ-ray telescope

This paper describes the balloon-flight version of a low energy (0.2-20 MeV) gamma-ray telescope developed in collabaration by the Milan and Southampton groups. The instrument embodies a Compton-coincidence system comprising an upper liquid scintillator and a large sodium iodide crystal (560 cm2). This detector is mounted inside a semiactive shielding system which collimates the incident photons (1.50 fwhm). The telescope is mounted in an orientation system which has a pointed accuracy of better than 0.50. The instrument has been extensively tested using beams of γ-rays, neutrons and high energy protons 12 GeV/c). (Auth.)