Collision of the Second Kind
collision of the second kind
[kə′lizh·ən əvthə ′sek·ənd ‚kīnd]Collision of the Second Kind
a collision between excited particles, such as atoms, ions, or molecules, or between such a particle and an electron where the internal excitation energy of the particles is converted completely or partially into kinetic energy of the colliding particles. Because of this mechanism, in collisions of the second kind the sum of the kinetic energies of the particles is greater after the collision than before the collision. By contrast, in elastic collisions there is no increase in the kinetic energy of the colliding bodies.