Radiation collimation in a thick crystalline undulator*
1 Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, 8000 Aarhus C., Denmark
2 Institut für Kernphysik Universität Mainz, J.-J.-Becher-Weg 45, 55099 Mainz, Germany
Received: 16 November 2016
Published online: 23 May 2017
With the recent experimental confirmation of the existence of energetic radiation from a Small Amplitude, Small Period (SASP) crystalline undulator [T.N. Wistisen, K.K. Andersen, S. Yilmaz, R. Mikkelsen, J. Lundsgaard Hansen, U.I. Uggerhøj, W. Lauth, H. Backe, Phys. Rev. Lett. 112, 254801 (2014)], the field of specially manufactured crystals, from which specific radiation characteristics can be obtained, has evolved substantially. In this paper we confirm the existence of the crystalline undulator radiation, using electrons of energies of 855 GeV from the MAinzer MIcrotron (MAMI) in a crystal that is approximately 10 times thicker than the previous one. Furthermore, we have measured a significant increase in enhancement, in good agreement with calculations, of the undulator peak by collimation to angles smaller than the natural opening angle of the radiation emission process, 1 /γ.
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2017