Gamma-Ray-Line Astronomy

The balloon and satellite detection of gamma rays from astrophysical sources is discussed. Supernovas and novas are considered with regard to the cosmic synthesis of the chemical elements, and particular attention is given to the production of gamma rays by neutron stars. Also discussed is gamma-ray-line broadening, and the generation of gamma rays by electron-positron annihilation, atomic nuclei emission, and electron cyclotron emission. A gamma-ray-line telescope is described which consists of a detector inside a detector, and contains 400 pounds of sodium iodide with tellurium atoms introduced as a dopant and a germanium crystal at the center.