Residence time
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 (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \exp(-t/\tau)} at long times. Historically, the concept was introduced to describe the time a particle is close to another [1], but it can be employed in other situations, as in diffusion at interfaces.
