Polarized photons from a silicon crystal in a 31 GeV electron beam at the Serpukhov proton accelerator

Abstract Tagged photons coherently emitted in a silicon crystal by the 31 GeV electron beam of intensity 4 × 10 4 ppp and beam pulse duration of up to 1.7 s have been obtained at the Serpukhov proton accelerator. The photon intensities were I ∼ 10 −1 − 10 −2 γ /e − in five almost equal energy bins within the total range k = (8.2−24.2) GeV. The calculated linear polarizations were P ∼ 50−20%, respectively. Narrow peaks in the radiation intensity were observed when varying the orientation of a silicon crystal which could not be explained. The method for the experimental alignment of a crystal in electron beams at the proton accelerator has been described.