To explore the laser kinetics of atomic xenon lasers pumped by an ultraviolet‐preionized, self‐sustained discharge, time‐resolved small‐signal gains are measured using a long‐pulse probe laser. Faster electron mixing processes among excited xenon manifolds in the 6pstate may affect the small‐signal gain distribution among 1.73, 2.03, and 2.65 &mgr;m laser lines, which share the same upper laser level Xe(5d[3/2]1) at excitation rates in excess of 160 kW/cm3. When the excitation rate in a late part of the discharge is increased, absorption caused by repumping of the lower laser level is observed at 1.73 &mgr;m. The measured gains are discussed in conjunction with multiline laser oscillation performance obtained by the same laser device.