The new injector for SPIRAL2 at GANIL, NEWGAIN is presently in its design phase. The major constraints for its technical concepts are determined by the requirements of its future users, the national French and the international scientific communities. The facility will offer heavy ion beams of unmatched intensity for fundamental and applied research. This document reports on the specific requirements of the scientific communities in terms of beam energy, intensity, time structure and other features which are needed to conduct the envisaged research programs at the experimental installations, which are or will be coupled to the linear accelerator of the SPIRAL2 facility at GANIL. It aims at fostering the information exchange between the scientific community and the technical and engineering team who is designing, planning and constructing NEWGAIN. The document has been elaborated by the members of the Work Package Physics (WPP) of the NEWGAIN project, consisting of the scientific coordinators of the institutions contributing to and participating in NEWGAIN, and representatives of the various scientific collaborations engaged in the exploitation of the SPIRAL2 accelerator facility. The document is organized with active links to sections, subsections, figures, tables and literature references integrated in the text.< Leer menos