Complete code (MATLAB) used to semi-analytically model atomic and molecular beam propagation in high-vacuum systems. The code calculates the expected attenuation of a neutral atomic/molecular beam due to (i) atoms/molecules backscattered from an optical element directly into the path of the incident beam (eta_S), and (ii) atoms/molecules that scatter away from the incident beam initially and contribute to the background gas pressure, in turn attenuating the beam (eta_B). We provide a single file (source_chamber_attenuation.m) that performs all theoretical calculations contained in the referenced manuscript. Simulation parameters are set at the start of the file and all outputs are generated with a single execution of the script. The script 'source_chamber_interference.m' is more generally useful, as it can be modified to investigate source chambers of interest to other investigators. It has been commented to ensure that this is straightforward.

All data analysis and presenting was performed in MATLAB 2024b and is compatible with the latest version.