pycroxe.beam.get_cross_sections_by_projectiles

pycroxe.beam.get_cross_sections_by_projectiles(conn: CroXeConnection, energies: ArrayLike, initial_projectiles: list[str], target: str, product_frame: str = 'projectile', sort_by: Sequence[SortKey] = ('year', 'rms')) → DataArray

Given a certain set of initial projectiles, retrieve all processes necessary to solve the problem of the evolution of the inital species, evaluate the cross-section for each process at each energy value in energies. and finally return the evaluated cross-sections tensor in the form of a xarray.DataArray.

Parameters

connpycroxe.CroXeConnection

An open pycroxe.CroXeConnection.

energiesarraylike

Energies in eV at which to evaluate the cross-sections. The provided arraylike is flattened out for convenience.

inital_projectileslist[str]

List of chemical symbols of the starting projectile species.

targetstr

Chemical symbol of the target species.

product_framestr, optional

Reference frame of the product after the collision (default: 'projectile').

sort_bySequence[pycroxe.beam.SortKey]

Ordered sequence of pycroxe.beam.SortKey values that determines the ORDER BY clause. The first key is the primary sort criterion, the second (if present) is the tiebreaker, and so on.

Returns

cross_sections_tensorxarray.DataArray

3-dimensional array of evaluated cross-sections with first dimension indexed by energy values, second dimension indexed by product species, and last dimension indexed by projectile species. Values where projectile == product represents total destruction processes cross-sections, hence they are negatively valued.

Raises

ValueError

If inital_projectiles or sort_by are empty.

Notes

The structure of the returned xarray.DataArray is such that it can be useful in solving problems of the like

\[\frac{d\Gamma_i}{dx} = n(x)\sigma_{ij}\Gamma_j\text{,}\]

where \(\Gamma_i\) and \(\Gamma_j\) are respectively the particle fluxes of the i-th product and the j-th species, while \(\sigma_{ij}\) is the cross-section of the process that trasnforms the j-th projectile into the i-th product.