title: Investigation of the Electromagnetic Radiation Emitted by Sub-GeV Electrons in a Bent Crystal.
abstract: The radiation emitted by 855 MeV electrons via planar channeling and volume reflection in a 30.5-μm-thick bent Si crystal has been investigated at the MAMI (Mainzer Mikrotron) accelerator. The spectral intensity was much more intense than for an equivalent amorphous material, and peaked in the MeV range in the case of channeling radiation. Differently from a straight crystal, also for an incidence angle larger than the Lindhard angle, the spectral intensity remains nearly as high as for channeling. This is due to volume reflection, for which the intensity remains high at a large incidence angle over the whole angular acceptance, which is equal to the bending angle of the crystal. Monte Carlo simulations demonstrated that incoherent scattering significantly influences both the radiation spectrum and intensity, either for channeling or volume reflection. In the latter case, it has been shown that incoherent scattering increases the radiation intensity due to the contribution of volume-captured particles. As a consequence, the experimental spectrum becomes a mixture of channeling and pure volume reflection radiations. These results allow a better understanding of the radiation emitted by electrons subjected to coherent interactions in bent crystals within a still-unexplored energy range, which is relevant for possible applications for innovative and compact x-ray or γ-ray sources.
authors.affiliation: INFN Sezione di Ferrara and Dipartimento di Fisica e Scienze della Terra, Università degli Studi di Ferrara Via Saragat 1, 44122 Ferrara, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Bandiera
authors.affiliation: INFN Sezione di Ferrara and Dipartimento di Fisica e Scienze della Terra, Università degli Studi di Ferrara Via Saragat 1, 44122 Ferrara, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Bagli
authors.affiliation: INFN Sezione di Ferrara and Dipartimento di Fisica e Scienze della Terra, Università degli Studi di Ferrara Via Saragat 1, 44122 Ferrara, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Germogli
authors.affiliation: INFN Sezione di Ferrara and Dipartimento di Fisica e Scienze della Terra, Università degli Studi di Ferrara Via Saragat 1, 44122 Ferrara, Italy.
authors.forename: V
authors.initials: V
authors.lastname: Guidi
authors.affiliation: INFN Sezione di Ferrara and Dipartimento di Fisica e Scienze della Terra, Università degli Studi di Ferrara Via Saragat 1, 44122 Ferrara, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Mazzolari
authors.affiliation: Institut für Kernphysik der Universität Mainz, Fachbereich Physik, Mathematik und Informatik, D-55099 Mainz, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Backe
authors.affiliation: Institut für Kernphysik der Universität Mainz, Fachbereich Physik, Mathematik und Informatik, D-55099 Mainz, Germany.
authors.forename: W
authors.initials: W
authors.lastname: Lauth
authors.affiliation: Università degli Studi dell'Insubria, Via Valleggio 11, 22100 Como, Italy and INFN Sezione di Milano Bicocca, Piazza della Scienza 3, 20126 Milano, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Berra
authors.affiliation: Università degli Studi dell'Insubria, Via Valleggio 11, 22100 Como, Italy and INFN Sezione di Milano Bicocca, Piazza della Scienza 3, 20126 Milano, Italy.
authors.forename: D
authors.initials: D
authors.lastname: Lietti
authors.affiliation: Università degli Studi dell'Insubria, Via Valleggio 11, 22100 Como, Italy and INFN Sezione di Milano Bicocca, Piazza della Scienza 3, 20126 Milano, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Prest
authors.affiliation: INFN Laboratori Nazionali di Legnaro, viale dell'Università 2, 35020 Legnaro, Italy and Dipartimento di Fisica, Università Di Padova, Via Marzolo 8, 35131 Padova, Italy.
authors.forename: D
authors.initials: D
authors.lastname: De Salvador
authors.affiliation: INFN Sezione di Trieste, Via Valerio 2, 34127 Trieste, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Vallazza
authors.affiliation: Research Institute for Nuclear Problems, Belarusian State University, 220030 Minsk, Belarus.
authors.forename: V
authors.initials: V
authors.lastname: Tikhomirov