Residence time
The residence time is the typical time of permanence of a particle in a given environment; more precisely, the decay time that appears in the exponential decay Failed to parse (Conversion error. Server ("https://wikimedia.org/api/rest_") reported: "Cannot get mml. Server problem."): {\displaystyle \exp(-t/\tau )} at long times. Historically, the concept was introduced to describe the time during which two particles are close to another (Ref. 1), but it can also be employed in other situations, such as in diffusion at interfaces.
