ИСТИНА

Using fractal analysis it was shown that films formatted in high frequency plasmotron plasma jet have structure close to fractal. Surface topology was investigated by scanning tunnel microscope “Umka”. Fractal surface can be easily constructed and used in numerical simulation of heterogeneous reactions especially in Direct Simulation Monte-Carlo method (DSMC). By now there are a number of works where heterogeneous reactions rates are calculated by quantum chemistry methods. It gives important information and allows to predict catalytic surface properties, but quantum chemistry methods don’t take into account that surface topology is not flat. In present work formulas were obtained for more accurate estimation of heterogeneous reactions rates for surfaces with fractal topology that are closed to real surfaces. Theoretical formulas were compared with numerical simulation and excellent agreement was received. Numerical simulation was made for the fractal surfaces using DSMC method. For example absorption probability equals a=1-(1-a0)^M, where a0 - absorption probability calculated by quantum chemistry method, M – average number of atom collisions with surface. This collisions number can be estimated as M=S/S0=(b/b0)^(2-D), where S – real surface square, S0 – square of surface projection to the plane, b – minimal size of surface roughness, b0 – atom collisionless free path, D – surface fractal dimension.