failures.strategy module

Define the function related to the strategy key of wtf.

In particular, it answers the question: Given this set of faults, which compensating cavities will be used?

Note

In order to add a compensation strategy, you must add it to the COMPENSATING_SELECTOR dict, and also to the list of supported strategies in config.wtf module.

failed_and_compensating(elts: ListOfElements, failed: Sequence[int] | Sequence[str] | Sequence[Sequence[int]] | Sequence[Sequence[str]], id_nature: Literal['cavity', 'element', 'name'], strategy: str, compensating_manual: Sequence[Sequence[int]] | Sequence[Sequence[str]] | None = None, **wtf: Any) → tuple[list[list[FieldMap]], list[list[FieldMap]]]

Determine the compensating cavities for every failure.

global_compensation(elements: Sequence, failed_elements: Sequence, *, remove_failed: bool = True, **kwargs) → Sequence

Give all the cavities of the linac.

Parameters:

• elements (Sequence[T]) – All the tunable elements.

• failed_elements (Sequence[T]) – Failed cavities.

Returns:

altered – Contains all the altered elements.

Return type:

list[T]

global_downstream(elements: Sequence, failed_elements: Sequence, *, remove_failed: bool = True, **kwargs) → Sequence

Give all the cavities after failure of the linac.

Parameters:

• elements (Sequence[T]) – All tunable the elements.

• failed_elements (Sequence[T]) – Failed cavities.

Returns:

altered – Contains all the altered elements.

Return type:

list[T]

k_out_of_n(elements: Sequence, failed_elements: Sequence, *, k: int, tie_politics: str = 'upstream first', shift: int = 0, remove_failed: bool = True, **kwargs) → Sequence

Return k compensating cavities per failed in elts_of_interest.

Note

T can represent a Element, or a list of Element. Returned type/data structure will be the same as what was given in arguments. This function is hereby also used by l_neighboring_lattices() which gives in lattices.

Parameters:

• elements (Sequence[T]) – All the tunable elements/lattices/sections.

• failed_elements (Sequence[T]) – Failed cavities/lattice.

• k (int) – Number of compensating cavity per failure.

• tie_politics ({'upstream first', 'downstream first'}, optional) – When two elements have the same position, will you want to have the upstream or the downstream first? The default is "upstream first".

• shift (int, optional) – Distance increase for downstream elements (shift < 0) or upstream elements (shift > 0). Used to have a window of compensating cavities which is not centered around the failed elements. The default is 0.

Returns:

altered – Contains all the altered elements/lattices. The n first are failed, the k * n following are compensating.

Return type:

list[T]

l_neighboring_lattices(elements_gathered_by_lattice: Sequence[Sequence], failed_elements: Sequence, *, l: int, tie_politics: str = 'upstream first', shift: int = 0, remove_failed: bool = True, min_number_of_cavities_in_lattice: int = 1, **kwargs) → Sequence

Select full lattices neighboring the failed cavities.

Every fault will be compensated by l full lattices, direct neighbors of the errors [1, 2]. You must provide l. Non-failed cavities in the same lattice as the failure are also used.

References

[1]

F. Bouly, J.-L. Biarrotte, and D. Uriot, “Fault tolerance and consequences in the MYRRHA superconducting LINAC,” in Proc. 27th Linear Accelerator Conf. (LINAC14). Geneva, Switzerland: JACoW Publishing, Geneva, Switzerland, 2014.

[2]

A. Plaçais and F. Bouly, “Cavity Failure Compensation Strategies in Superconducting Linacs,” in Proceedings of LINAC2022, 2022, pp. 552–555. doi:10.18429/JACoW-LINAC2022-TUPORI04

elements_by_latticeSequence[Sequence[T]]

Tunable elements sorted by lattice.

failed_elementsSequence[T]

Failed cavities/lattice.

lint

Number of compensating lattice per failure.

tie_politics{‘upstream first’, ‘downstream first’}, optional

When two elements have the same position, will you want to have the upstream or the downstream first? The default is "upstream first".

shiftint, optional

Distance increase for downstream elements (shift < 0) or upstream elements (shift > 0). Used to have a window of compensating cavities which is not centered around the failed elements. The default is 0.

remove_failedbool, optional

To remove the failed lattices from the output. The default is True.

min_number_of_cavities_in_latticeint, optional

If a lattice has less than this number of functional cavities, we look for another lattice. This is designed to removed lattices which have no cavities (default value: 1). Note that lattices that have some functional cavities but not enough will be used for compensation anyway.

Returns:

altered – Contains all the altered cavities.

Return type:

list[T]

manual(failed_cavities: Sequence[list[FieldMap]], compensating_cavities: list[list[FieldMap]] | Any) → tuple[list[list[FieldMap]], list[list[FieldMap]]]

Associate failed with compensating cavities.