Crossed source–detector geometry for a novel spray diagnostic: Monte Carlo simulation and analytical results

Abstract

Sprays and other industrially relevant turbid media can be quantitatively characterized by light scattering. However, current optical diagnostic techniques generate errors in the intermediate scattering regime where the average number of light scattering is too great for the single scattering to be assumed, but too few for the diffusion approximation to be applied. Within this transitional single-to-multiple scattering regime, we consider a novel crossed source-detector geometry that allows the intensity of single scattering to be measured separately from the higher scattering orders. We verify Monte Carlo calculations that include the imperfections of the experiment against analytical results. We show quantitatively the influence of the detector numerical aperture and the angle between the source and the detector on the relative intensity of the scattering orders in the intermediate single-to-multiple scattering regime. Monte Carlo and analytical calculations of double light-scattering intensity are made with small particles that exhibit isotropic scattering. The agreement between Monte Carlo and analytical techniques validates use of the Monte Carlo approach in the intermediate scattering regime. Monte Carlo calculations are then performed for typical parameters of sprays and aerosols with anisotropic (Mie) scattering in the intermediate single-to-multiple scattering regime.

Image transfer through the complex scattering turbid media

“…In this letters, we present a new MC based model for simulation of image transfer through the turbid highly scattering medium. This model is a natural extension of the technique developed recently [2,3]. The technique allows to consider complex poly-disperse turbid media with the strong variations of the scattering particles concentration [4].…”

“…1) in our case. The azimuthal scattering angle φ s is uniformly distributed and selected randomly in a range 0 to 2π [3,4]. Since a new direction for the photon packet is defined a new free photon path-length is simulated, and coordinates of the next scattering event is counted.…”

Scalar Radiative Transfer in Discrete Media With Random Oriented Prolate Spheroids Particles

“…Berrocal et al used Monte Carlo method to calculate some typical aerosols with Mie scattering in the intermediate single-to-multiple scattering regime. And they developed a novel Monte Carlo code for modeling optical radiation propagation in inhomogeneous polydisperse scattering media [15][16][17]. The multiple scattering effect in Monte Carlo simulation was also discussed by Meglinski et al [18].…”

Forced Detection Monte Carlo Algorithms for Accelerated Blood Vessel Image Simulations

“…Another variance reduction method, foremost used in atmospheric optics, nuclear and particle physics, and radiology, is forced detection (FD) [8][9][10][11][12]. This method is useful when the probability for a photon to hit the detector is very low [12].…”