Ionization associated with solid particles

Ionization Associated with Solid Particles in Flames... 

Ionization associated with the presence of solid particles in flames is small and easily obscured by gaseous ionization of volatile impurities. It can be demonstrated experimentally in certain systems and can be shown to depend on the particle size, number density, and work function as predicted by the theory of Smith or Soo and Dimick. Salts such as the alkali halides volatilize slowly and mix by diffusion. Residual inhomogeneities in ion distribution give the appearance of particulate ionization. 

As a result of these studies, a considerable and coherent body of information exists about the ionization kinetics, energetics, and processes for many volatile additives. The presence of solid particles in the flame has always been associated with ionization, and this chapter describes some attempts to make and interpret such observations. 

Besides the ion range or damage range distribution associated with ion/solid interactions there is also the depth distribution for the sputtered particles. This distribution is sharply peaked at the sample surface so that most of the sputtered atoms come from the top monolayer. For a light atom in a heavy matrix this value is believed to be somewhat larger. This result is predicted by Sigmund s (15) theory. For sputtered atoms from a metallic target that are ionized, i.e., those that are used in SIMS, their depth distribution is more sharply peaked in the top monolayer because of the efficient neutralization processes that occur for ions created below the top monolayer. 

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