477 research outputs found
Deterministic growth model of Laplacian charged particle aggregates
The results of the computer simulation of the aggregates growth of the
similarly charged particles in the framework of deterministic Laplacian growth
model on a square lattice are presented. Cluster growth is controlled by three
parameters , where - Laplacian growth parameter, -
energy of a particle sticking to a cluster, - the screening length of
electrostatic interactions. The phase diagram of cluster growth is built in the
co-ordinates . The zones of different cluster morphology are
selected: I-the zone of finite X-like structures,II-the zone of infinite
ramified structures, controlled by electrostatic interactions, III-the zone of
infinite structures with electrostatic interactions effectively switched off.
Simple electrostatic estimations of the locations of the zone boundaries are
presented. It is shown that in general case within the zone II the continuous
change of , controlled by parameters , takes place. In the
degeneration limit when the given model transforms into deterministic version
of the Eden model (at ), the crossover from linear to compact
structures is observed when passing through the boundary between the
zones I and II.Comment: REVTEX, 3 pages with 4 postscript figure
Analytical-numerical methods of calculations of energy and three-dimensional particle distributions in electromagnetic cascades
Analytical and numerical methods of calculation of the energy and three dimensional EPS characteristics are reported. The angular and lateral functions of electrons in EPS have been obtained by the Landau and small angle approximations A and B and compared with earlier data. A numerical method of solution of cascade equations for the EPS distribution function moments has been constructed. Considering the equilibrium rms angle as an example, errors appearing when approximating the elementary process cross sections by their asymptotic expressions are analyzed
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