Passarelli, D. Nicol, T.H. Parise, M. Ristori, L. JACoW Geneva, Switzerland 978-3-95450-178-6 10.18429/JACoW-SRF2015-TUPB074 English 754-756 TUPB074 vacuum cavity cryomodule simulation niobium Contribution to a conference proceedings 2015 2015-12 http://dx.doi.org/10.18429/JACoW-SRF2015-TUPB074 http://srf2015.vrws.de/papers/tupb074.pdf In order to guarantee an effective cool-down process for the SSR1 cryomodule, a high-vacuum level must be achieved at room temperature in the beam-line before introducing gaseous and liquid helium. The SSR1 cavities in the beamline have a small beam aperture compared to the size of their internal volume. To avoid unnecessary complications for the vacuum piping of the cryomodule cold-mass, a pilot study was conducted on the string prior to processing and qualification of the components to investigate the vacuum level achievable by pumping only through the beam-line. To estimate the pressure distribution inside the cavity string we used a mathematical model implemented in a test-particle Monte-Carlo simulator for ultra-high-vacuum systems.