1. L. Hocker, M. Kovacs, C. Rhodes, G. Flynn, and A. Javan, Phys. Rev. Letters 17, 5 (1966).PRLTAO0031-9007
2. The Mylar cylinder required no window since it transmits about 70% at 4.3 μ. This cylinder was used to eliminate any changes in the boundary condition attributable to a nonuniform surface caused by the presence of the infrared transmitting window.
3. J. O. Hirschfelder, C. F. Curtiss, and R. B. Bird, Molecular Theory of Gases and Liquids (John Wiley & Sons, Inc., New York, 1954), p. 13, 14.
4. The continuity equation yields the boundary condition μJ1(μ)−(ν̄r0/2D)[(1−β)/(1+β)]J0(μ) = 0, where J0 and J1 are Bessel functions of order 0 and 1.
5. The above theory predicts the constant, (ν̄/r0)[(1−β)/(1+β)]. Although diffusion theory is not valid in this limit, the predicted decay rate agrees with experimental observation.