A PROCEDURE FOR COMPUTING CHARACTERISTICS OF AN ELECTROMAGNETIC FIELD EXCITED BY AN INTENSE GAMMA BEAM IN AIR

G. G. Bliznуuk, A. V. Ivanоvsкy, A. A. Sоlоvуоv
VANT. Ser. Mat. Mod. Fiz. Proc 1991. Вып.2. С. 51-56.

      A mathematical formulation and a numerical method are described for computing electromagnetic field parameters in the vicinity of a strong gamma quantum beam moving through the air. The field characteristics are derived from a 1-D system of equations obtained with a running wave approximation. A system of ionization kinetics equations is solved to find a radiation-induced conduction in the medium. The sources, that is current density of charged particles produced by gamma quanta (electrons and positrons) and air ionization intensity are determined by solving equations with a self-consistent field and a collision integral in the Focker-Plank form. A numerical example is given.

      A turbulent diffusion semi-empirical equation is used to consider the transport of aerosol particles in air. Velocity and diffusion coefficients are assumed to be only a function height. The Monte Carlo method is applied to numerically solve the diffusion equation with the attention focused on (Calculating the density of particle precipitation on an underlying surface.
      A source equation factorization is proposed, which allows to obtain a solution for a 3-D problem by modelling a 1-D diffusion process with height.
      Analytic solutions for a 1-D diffusion equation with constant coefficients served to develope an efficient scheme for numerical simulation of particle paths. Problems having analytical solutions were used to show the possibilities of the procedure.
      The procedure proposed can be applied to a broad class of problems in air and envir6nment physics.