Study of a high-$\beta\ Insertion Optics for the TOTEM Experiment at the LHC Version 5.0: the Case of IR1 and IR5

The TOTEM experiment is intended to measure the total cross section, elastic scattering and diffraction dissociation at the LHC energies. For those measurements, we have to detect particles emitted in the very forward region. The experimental method, techniques and optics layout which are involved are quite different from those used in the large general purpose detectors. A systematic study of all the possible interaction region is currently under way. In this paper we present a first step towards the design of an optimized high-beta insertion for IR1 and IR5. Our first objective is to fulfil t he requirements without special infrastructure and at minimum cost.