Evaporative cooling at low trap depth

A quantitative, analytic model of evaporative cooling covering both the small- $(<4)$ and large- $(>4)$ η regimes is presented. η is the dimensionless parameter defined as the trap depth divided by the temperature of the trapped sample. Although some of the same general properties present at large η are also present at small η, there are significant quantitative differences. These differences must be taken into account in order to accurately extract from the trapping data quantitative measurements of, for example, collisional atomic cross sections.