I present some details on the Stationary Interferometer Simulation tool we employed at Virgo to determine the scattered light distribution around the test masses, relevant for the instrumented baffles under construction at IFAE. The simulation calculates fields in a stationary interferometer. It uses fast fourier transform methods and considers realistic details of optical components, like macroscopic shapes and microscopic surface phase-maps.
Marc Manera, Pere Masjuan, Stefano Terzo