The CERN Gamma Factory Initiative: An Ultra-High Intensity Gamma Source

This contribution discusses the possibility of broadening the present CERN research programme making use of a novel concept of light source. The proposed, Partially Stripped Ion beam driven, light source is the backbone of the Gamma Factory (GF) initiative. It could push the intensity limits of the presently operating light-sources by 7 orders of mag- nitude, reaching the flux of up to $10^{17}$ photons/s. It could operate in the particularly interesting $\gamma$-ray energy domain of $1 \leq E \gamma \leq 400$ MeV. This domain is out of reach for the FEL-based light sources based on sub-TeV energy-range electron beams. The unprecedented-intensity, energy-tuned, gamma beams, together with the gamma-beams-driven secondary beams of polarized positrons, polarized muons, neutrinos, neutrons and radioactive ions would constitute the basic research tools of the proposed Gamma Factory. A broad spectrum of new opportunities, in a vast domain of uncharted fundamental and applied physics territories, could be opened by the Gamma Factory research programme.