Diffusion-limited reaction in one dimension: Paired and unpaired nucleation.

Journal of Chemical Physics 115 73 (2001)

Salman Habib

Theoretical Division T-8, Los Alamos National Laboratory
New Mexico 87545, USA.

Katja Lindenberg

Department of Chemistry and Biochemistry 0340, University of California San Diego
La Jolla, California 92093-0340.

Grant Lythe

Theoretical Division T-8, Los Alamos National Laboratory
Los Alamos, New Mexico 87545
and
GISC, Departamento de Matemáticas, Universidad Carlos III de Madrid
28911 Leganés, Spain.

Carmen Molina-París

Theoretical Division T-8, Los Alamos National Laboratory
Los Alamos, New Mexico 87545
and
Centro de Astrobiología CSIC-INTA
Carretera de Ajalvir, 28850 Torrejón, Madrid, Spain.

Abstract

We study the dynamics of diffusing particles in one space dimension with annihilation on collision and nucleation (creation of particles) with constant probability per unit time and length. The cases of nucleation of single particles and nucleation in pairs are considered. A new method of analysis permits exact calculation of the steady state density and its time evolution in terms of the three parameters describing the microscopic dynamics: the nucleation rate, the initial separation of nucleated pairs and the diffusivity of a particle. For paired nucleation at sufficiently small initial separation the nucleation rate is proportional to the square of the steady state density. For unpaired nucleation, and for paired nucleation at sufficiently large initial separation, the nucleation rate is proportional to the cube of the steady state density.