Abstract
The absorption spectrum of a CsBr : Pb2+ crystal shows remarkable isothermal changes. In the temperature range near 80 °C, the absorption constants of most of the component bands decay with time, while the 316 nm band grows. The change is caused by second‐order kinetics. Reaction velocities classify the bands into two groups, the defects responsible for the spectrum consist of two types of defects including I–V dipoles.