Trapping by clusters of traps

We study how the trapping kinetics is modified when traps are gathered in c lusters. Recently, we have proposed a mean-held theory of trapping by clust ers of traps valid at the initial stage of the process [J. Chem. Phys. 111, 711 (1999)]. Here by using the optimal-fluctuation method we incorporate f luctuation effects in the theory and discuss the manifestation of trap clus tering in the kinetics over the entire time domain. Notable observations ar e that due to trap clustering (1) the trapping kinetics can be significantl y modified from the very beginning of the process; (2) the fluctuation-indu ced kinetics exhibits more rich behavior; (3) the fraction of particles rea cting according to a stretched-exponential law can be substantially increas ed.