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D3DEnergetic / FIDASIM

A Neutral Beam and Fast-ion Diagnostic Modeling Suite
http://d3denergetic.github.io/FIDASIM/
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neutral-neutral collisions #190

Open heidbrin opened 4 years ago

heidbrin commented 4 years ago

Out in the scrapeoff layer, neutral-neutral collisions can be an important excitation method. For passive modeling, we should consider incorporating these cross-sections into the collisional--radiative equations.

lstagner commented 4 years ago

Does anyone have a good source for the cross sections?

bgrierson21 commented 4 years ago

https://doi.org/10.1088/0022-3700/15/9/014 See Fig. 3 for H with H2.

shaunhaskey commented 4 years ago

http://iopscience.iop.org/0370-1298/66/11/301 Fig 4,5,6 for impact excitation of H by H. No idea of the quality though.

lstagner commented 4 years ago

Here are the Hydrogen-Hydrogen cross sections available from the ALADDIN Atomic Database Screenshot from 2020-04-10 15-05-11 image

Looks like we are missing excitation from the n=2 state to the n=3 and none of the available data goes beyond n=3 so some assumptions will have to be made to fill out the n/m matrix.

I am unsure as to handle molecular hydrogen (H_2, H_3) since we don't know the concentration of each species. Perhaps it best to just assume that the neutrals are all H_1.

lamorton commented 4 years ago

I second this feature request -- it would be useful for beam-into-gas calibrations as well.