On the role of the adjoint Boltzmann equation in the calculation of energy deposition

Abstract

The adjoint Boltzmann equation is used to develop a formalism for calculating energy deposition in moderators. Examples of the technique are given and include a point source of fast neutrons in an infinite medium and a uniform source in a sphere of finite radius. Using elastic scattering to describe the slowing down process, the heat rates in moderators with mass numbers 1, 2, 3, 4, 5, 10, 16 and 50 are calculated. The results are compared with some recent Monte Carlo calculations on compressed pellets of deuterium and tritium and good agreement is found.

Once‐more scattered next event estimation for volume rendering

“…Closed‐form solutions are rare and normally not general enough to be useful for computer graphics. For our specific case, there exist approaches [Wil77; dEo16] but do not generalise to arbitrary phase functions and are valid for point light sources only. Furthermore, they do not allow for Monte Carlo sampling of other sources of variation such as occlusion and general emitter distribution functions.…”