Photonuclear reactions by relativistic electron channeling radiation

Abstract

The research for newly developing branch of nuclear physics, the nuclear photonics, has been accompanied since the beginning with the studies on intense MeV photon sources. One of the possible solution is in the use of channeling radiation. The channeling radiation spectrum for sub-GeV–several GeV electrons is characterized by a sharp maximum at photon energies up to several MeV, which is enough to excite separate nuclear levels as well as (γ,n) reaction for light Be and D nuclei. This maximum may even reach the region of giant dipole resonance for heavier nuclei. At equal radiator thickness the channeling radiation flux may exceed in more than one order that of bremsstrahlung. Thus, channeling radiation can be efficiently utilized in studying photonuclear reactions as well as generating pulsed neutron beams at sub-GeV electron accelerators. The latter is illustrated by detailed calculations of the neutrons yield from the light D and Be targets irradiated by channeling radiation. The non-trivial dependence of neutrons yield on the energy of incident electron beam and on the electron beam alignment with respect to the crystal channeling planes is revealed.