Radiation from spectral lines can be absorbed and re-emitted many times in atomic vapours before it reaches the boundaries of the container encasing the vapour. This effect is known as radiation trapping. It plays an important role practically everywhere where atomic vapours occur, including spectroscopy, gas lasers, atomic line filters, determination of atomic lifetimes, measurements of atomic interaction potentials, and electric discharge lamps. Radiation Trapping in Atomic Vapours, written by leading authorities in the field, assembles for the first time all the information necessary for a treatment of practical problems, emphasizing both physical insights and mathematical methods. It is both self-contained and comprehensive, and will be of interest to graduate students and researchers in this area.