Influence of gas density on measuring clusters size by Rayleigh scattering method

The Rayleigh scattering method is widely adopted in measuring cluster size. In general, it is considered that the intensity of scattering corresponds to the cluster size directly. However, this paper deduces that the intensity is not only related to cluster size, but also to gas density and binding probability. It suggests that gas density should be taken into account in analyzing the measurement results of Rayleigh scattering method. Furthermore, the method is applied in measuring the size distribution of argon cluster along the axis of nozzle. It is found that the cluster size doesn’t vary linearly along the nozzle axis, whereas it reaches maximum at a certain position which depends on some parameters including the background pressure．