I am working on ionization chambers and I was wondering if the implementation of ion-ion recombination could be easy to do.
Hence the recombination is described, similarly to electron attachment, with a attachment coefficient \alpha~[cm^3s^{-1}] and the evolution of ion density follows
n(t) = n_0 \frac{1}{1+\alpha n_0 t}.
I have the feeling that this implementation could be quite straightforward. What do you all think ?
In my specific case the electron-ion attachment could be neglect, so it’s not relevant.
No I’m still digging this direction, but I would like to experiment with it. I’m working in laboratory air, and this paper [1] proposes some measured values and a fit adjustment of \alpha as a function of temperature and humidity.
This other paper [2] suggests a fixed value of \alpha for laboratory air in dosimetry works.
And this third one [3] looks interesting, even if they study recombinations in field free regions, they highlight a relation between the recombination coefficient and the initial ion density.
Do you think that even with an incomplete model of the recombination parameter α, the implementation of recombination could still be possible, at least to verify the model in some specific cases?
Hi,
sorry for the super-late reply! Yes, I think that should be possible; we would need to
add a function to the Medium class that returns the “recombination coefficient” as function of the electric field, and
adapt the algorithm in AvalancheMC (or are you using DriftLineRKF).
There is an existing function in Medium that is supposed to return the ion “dissociation coefficient” as function of the applied field. But this parameter is not used anywhere in the transport algorithms. So for testing things, we could perhaps just repurpose that function. In the end, I guess it’s quite similar in the sense that both in case of recombination and dissociation, the ion “disappears”?