Parton Distributions at the LHeC

The LHeC provides e±p collisions at 1.4 TeV cms energy. Based on simulations of the statistics and the systematics as may be achieved with a new collider detector, the potential of the LHeC is characterised regarding DIS precision measurements as of the strong coupling constant, to per mille accuracy, and the gluon distribution. It is demonstrated that for the first time the flavour contents of the proton can be completely reconstructed. Precision measurements will be possible of the up, down, strange, charm, beauty, anti-up, anti-down and anti-strange quark distributions over a huge range in x and Q hitherto not accessible. This is solely based on high precision neutral and charged current measurements, in ep and partially in eD scattering, using charm and beauty tagging for the reconstruction of the heavy quark momentum distributions.