dispersal vs scattering

dispersal

noun
  • The act or result of dispersing or scattering; dispersion. 

  • A dispersal prison. 

scattering

noun
  • The process whereby a beam of waves or particles is dispersed by collisions or similar interactions. 

  • The total number of votes awarded to nonmajor or unlisted candidates. 

  • A small quantity of something occurring at irregular intervals and dispersed at random points. 

How often have the words dispersal and scattering occurred in a corpus of books? (source: Google Ngram Viewer )