Measurement of Absolute Atomic Collision Cross Section with Helium Using ⁸⁷Rb Atoms Confined in Magneto-Optic and Magnetic Traps

We present the measurements and calculations of the absolute total collision cross sections for a room-temperature gas of helium using ⁸⁷Rb atoms confined in either a magneto-optic or a magnetic quadrupole trap. The loss rates from the magneto-optic trap and the pure magnetic trap are compared and show significant differences. The collision cross sections as a function of trap depth for helium gas are obtained. These findings are significant for extracting the information about the different cross sections when the trap depth is changed.