Polarimetry of coherent polarization radiation

Polarization properties of coherent polarization X-radiation produced by a low-emittance electron beam of 72 MeV interacting with a silicon monocrystal have been investigated experimentally at the superconducting Darmstadt linear accelerator S-DALINAC. Spatially and energetically resolved measurements of the direction and the degree of linear polarization show good agreement with expectations based on the kinematical theory of coherent polarization radiation and rule out a quasi-Černekov nature of the radiation

Production of Linearly Polarized Photon Beam at Max-Lab

Spectra of coherent bremsstrahlung from the diamond crystal in the laboratory MAX-lab on the accelerator MAX-I are measured at the energy of the electronic beam 144 MeV. First in the laboratory MAX-lab a source of the polarized photon radiation was created. Photon spectra were compared with theoretical calculations, that allow to estimate a magnitude of photon polarization, which is sufficient, for performing the nuclear experiments in the intermediate energy range

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 (~ 1 GeV) and are well described by coherent bremsstrahlung theory. The linear polarization of the uncollimated beam at the coherent peak energy ≈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 ≈80 MeV