  This year, 2015, marks the centenary of the publication of Einsteins Theory
of General Relativity and it has been named the International Year of Light and
light-based technologies by the UN General Assembly. It is thus timely to
discuss the possibility of broadening the present CERN research program by
including a new component based on a novel concept of the light source which
could pave a way towards a multipurpose Gamma Factory. The proposed light
source could be realized at CERN by using the infrastructure of the existing
accelerators. It could push the intensity limits of the presently operating
light-sources by at least 7 orders of magnitude, reaching the flux of the order
of 10^17 photons/s, in the particularly interesting gamma-ray energy domain of
1 < Ephoton < 400 MeV. This domain is out of reach for the FEL-based light
sources. The energy-tuned, quasi-monochromatic gamma beams, together with the
gamma-beam-driven, high intensity secondary beams of polarized positrons,
polarized muons, neutrons and radioactive ions would constitute the basic
research tools of the proposed Gamma Factory. The Gamma Factory could open new
research opportunities in a vast domain of uncharted fundamental physics and
industrial application territories. It could strengthen the leading role of
CERN in the high energy frontier research territory by providing the
unprecedented-brilliance secondary beams of polarized muons for the
TeV-energy-scale muon collider and the polarized- muon-beam based neutrino
factory.
