Recoil generation fix for z-directed particles #288
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
added 3 commits
June 11, 2025 10:32
drobnyjt
changed the title
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Thank you for your contribution to rustBCA!
Before submitting this PR, please make sure you have:
Fixes #286
Description
User @dmonah observed deviations in sputtering yields when ions were incident on a flat surface from different directions (e.g., other than in the +x direction).
dmonah did lots of tests that suggested the problem lay in the recoil generation routine. These routines were a big part of the problem, as they introduced two issues for incident directions with non-zero z elements: first, a subtle distortion in the recoil locations is introduced for directions close to +/-z. Second, generated recoils were not consistently located in the plane of atomic deflection. This caused near-surface physics - particularly, low energy reflection and sputtering - to be affected for any incident atoms with a significant +/- z component to their velocity.
To fix this, I re-derived formulas for the recoil location and deflection. The updated formulas keep these directions consistent for all incident directions, fixing the issue
Tests
See comments in #286 for details on the various tests I'm running to make sure this is working correctly.