Experimental investigation of the radiation produced by the passage of 10-GeV electrons and positrons through single crystals

A facility for investigating the radiation produced by high-energy electrons and positrons is described. The facility Kristall was built at the Institute of High Energy Physics in 1980. It ensured a resolution in the angle of entry of the particles into a crystal of about 6 μrad, and in the angle of exit of 30 μrad; for some events the emission angles of the γ rays were measured with an accuracy of about 4 μrad. The targets were dislocation-free single crystals. Experiments made with Kristall gave information about the radiation produced in the case of axial and planar channeling of 10-GeV electrons and positrons in silicon and germanium single crystals. The properties of the electromagnetic radiation for different angles of entry into the crystal and also data on the radiative energy losses are given. Angular distributions of the radiation were measured for the first time. Data are also given on the coherent bremsstrahlung of relativistic electrons and positrons in thin silicon single crystals