Design concept of a -ray beam with low bandwidth and high spectral density

The Variable Energy Gamma facility of the Extreme Light Infrastructure-Nuclear Physics center will deliver a gamma beam generated by the Compton scattering of laser and electron beams. It will have the highest spectral density and the lowest bandwidth available worldwide. A suite of several experimental setups is being developed for a wide range of research programs in fundamental and applied nuclear science driven by gamma beams. The proposed design concept for this facility is outlined. A study of the gamma beam properties at its source, as well as those after collimation, is presented. The impact of the variation in the parameters of the electron and laser beams on the quality of the gamma beam is analyzed and discussed.