The PERC project addresses a number of questions of particle physics, with main emphasis on the search for new physics beyond the Standard Model of particles physics, and in particular, on the question of unification of all forces shortly after the Big Bang. This grand unification is not part of the Standard Model, and new symmetry concepts are needed like left-right symmetry, fundamental fermion compositeness, new particles, leptoquarks, supersymmetry, and many more. Precise symmetry tests of various kinds are coming within reach with the proposed facility PERC, where count rates of neutron decay products are increased by a factor 100 compared to best experiments. Our goal is beta - spectroscopy, where the spectra and angular distributions of the emerging decay particles will be distortion-free on the level of 10−4.