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  2. Collision frequency - Wikipedia

    en.wikipedia.org/wiki/Collision_frequency

    Collision frequency describes the rate of collisions between two atomic or molecular species in a given volume, per unit time. In an ideal gas , assuming that the species behave like hard spheres, the collision frequency between entities of species A and species B is: [ 1 ]

  3. Collision theory - Wikipedia

    en.wikipedia.org/wiki/Collision_theory

    For particles in a solution, an example model to calculate the collision frequency and associated coagulation rate is the Smoluchowski coagulation equation proposed by Marian Smoluchowski in a seminal 1916 publication. [4]

  4. Plasma parameters - Wikipedia

    en.wikipedia.org/wiki/Plasma_parameters

    The plasma collisionality is defined as [4] [5] =, where denotes the electron-ion collision frequency, is the major radius of the plasma, is the inverse aspect-ratio, and is the safety factor. The plasma parameters m i {\displaystyle m_{\mathrm {i} }} and T i {\displaystyle T_{\mathrm {i} }} denote, respectively, the mass and temperature of the ...

  5. Steric factor - Wikipedia

    en.wikipedia.org/wiki/Steric_factor

    Also called the probability factor, the steric factor is defined as the ratio between the experimental value of the rate constant and the one predicted by collision theory. It can also be defined as the ratio between the pre-exponential factor and the collision frequency, and it is most often less than unity.

  6. Mean free path - Wikipedia

    en.wikipedia.org/wiki/Mean_free_path

    where ℓ is the mean free path, n is the number of target particles per unit volume, and σ is the effective cross-sectional area for collision. The area of the slab is L 2, and its volume is L 2 dx. The typical number of stopping atoms in the slab is the concentration n times the volume, i.e., n L 2 dx. The probability that a beam particle ...

  7. Reaction rate constant - Wikipedia

    en.wikipedia.org/wiki/Reaction_rate_constant

    The equation for the rate constant is similar in functional form to both the Arrhenius and Eyring equations: k ( T ) = P Z e − Δ E / R T , {\displaystyle k(T)=PZe^{-\Delta E/RT},} where P is the steric (or probability) factor and Z is the collision frequency, and Δ E is energy input required to overcome the activation barrier.

  8. Pre-exponential factor - Wikipedia

    en.wikipedia.org/wiki/Pre-exponential_factor

    In chemical kinetics, the pre-exponential factor or A factor is the pre-exponential constant in the Arrhenius equation (equation shown below), an empirical relationship between temperature and rate coefficient. It is usually designated by A when determined from experiment, while Z is usually left for collision frequency. The pre-exponential ...

  9. Direct simulation Monte Carlo - Wikipedia

    en.wikipedia.org/wiki/Direct_simulation_Monte_Carlo

    From the collision frequency, , given by kinetic theory the total number of hard sphere collisions in a cell during a time is = = where is the particle diameter and is the volume of the cell.