TOTEM Experiment: Elastic and Total Cross Sections

The physics programme and the detector apparatus of the TOTEM experiment is presented. Then, the key optics and their goals are summarised. The method to measure the total pp cross section is introduced. One of its essential parts, the extrapolation to t = 0, is discussed in detail and extrapolation strategies for = 1535 and 90 m optics are presented. In particular, an adequate parameterisation and a treatment of Coulomb scattering is proposed. In the last section, a Roman Pot alignment procedure is described.