The Collaborative International Dictionary of English v.0.48:

atomisation \atomisation\ n.
   1. separating something into fine particles.

   Syn: atomization, fragmentation
        [WordNet 1.5]

   2. annihilation by reducing something to atoms.

   Syn: atomization
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

atomisation
    n 1: separating something into fine particles [syn:
         atomization, atomisation, fragmentation]
    2: annihilation by reducing something to atoms [syn:
       atomization, atomisation]