Calculating Particle Energy Loss in Gases: Where to Start?

[md123]

Hey guys,

Im currently looking for a way to calculate the energy loss of a particle in a gas. This will help me to understand deposition processes better. The particles I am looking at are heavy, uncharged ones (e.g. metal atoms). Stopping power is not a viable concept without charge, and Bethe Bloch seems to only work for higher energies (>0.5MeV), whereas the energies I am looking at are in the order of eV, or some few keV at most.
I can't find a good solution for my problem, maybe you can give me a hint where to start, a theory, a formula... anything? Id sure appreciate any form of help!

So long,
md

 

[mfb]

Particles of the order of eV are nearly thermal, they will stop within some small multiple of the mean free path in the gas, where the prefactor depends on the mass ratio between stopped particle and the gas molecules (or atoms at higher energy).
At higher energies, chemical processes and ionization get possible, where I don't know how to describe that.

 

[md123]

Since its Ar-gas, its monoatomic and perfectly inert, so i don't have to think about the distinction of molecular and atomic scattering or chemical processes. I guess i could just run a simulation using simple mechanics, scattering factors and angular distributions, and use random numbers to get a result...

 

[mfb]

Probably. Ionization will be a possible source of energy loss, so elastic collisions give an upper estimate on the distances and timescales involved.

 

[md123]

Thanks for the input and encouragement. How do people say? "Aint nothing to in but to do it". I will try!