Linearly polarized photon beam at MAX-lab

A linearly polarized photon beam has been produced at MAX-lab using the coherent bremsstrahlung of electrons with an energy of 192.6 MeV in a 0.1 mm thick diamond crystal. The intensity and shape of the coherent maxima and their dependence on the crystal orientation are similar to the features observed at higher electron energies (similar to 1 GeV) and are well described by coherent bremsstrahlung theory. The linear polarization of the uncollimated beam at the coherent peak energy approximate to 50-60 MeV is about 20% and can be increased to 40-45% if collimation of half the characteristic angle is used At present the degree of polarization is high enough to allow the study of polarization observables in photo-nuclear reactions at MAX-lab in the energy range from Giant Dipole Resonance up to approximate to 80 MeV. (C) 2014 Elsevier B.V. All rights reserved