Survival probabilities in the double trapping reaction A +B -> B, B + C   -> C
  We consider the double trapping reaction A + B -> B, B + C -> C in one dimension. The survival probability of a given A particle is calculated under various conditions on the diffusion constants of the reactants, and on the ratio of initial B and C particle densities. The results are of more general form than those obtained in previous work on the problem. 
Alan J. Bray, Richard Smith