pyaml.tuning_tools.chromaticity#

Chromaticity correction and response-matrix tools.

The Chromaticity tool reads measured chromaticity, computes sextupole strength corrections from a response matrix, and applies those corrections to an accelerator model or control-system interface.

Classes

Chromaticity(name, sextu_array_name, ...)

Adjust horizontal and vertical chromaticity with sextupole strengths.

class pyaml.tuning_tools.chromaticity.Chromaticity(name, sextu_array_name, chromaticity_monitor_name, response_matrix)#

Bases: TuningTool, DynamicValidation

Adjust horizontal and vertical chromaticity with sextupole strengths.

A response matrix maps sextupole-strength changes to chromaticity changes. Its pseudoinverse is used to calculate the strength correction required for a requested chromaticity change.

Parameters:

name (str) – Name of the tuning tool.
sextu_array_name (str) – Name of the sextupole array used to adjust the chromaticity.
chromaticity_monitor_name (str) – Name of the chromaticity monitor used for readback.
response_matrix (str | ResponseMatrixData) – Chromaticity response matrix or path to a saved response matrix file.

Attributes

`response_matrix`	Return the loaded chromaticity response matrix, if available.
`chromaticity_monitor`	Return the chromaticity monitor used for readback.
`sextupoles`	Return the sextupole array used for correction.

Methods

`load()`	Load a chromaticity response matrix and prepare its pseudoinverse.
`get()`	Return the requested horizontal and vertical chromaticity.
`readback()`	Measure and return the current horizontal and vertical chromaticity.
`set()`	Iteratively correct chromaticity to a requested setpoint.
`correct()`	Calculate sextupole-strength changes for a chromaticity change.
`add()`	Apply a chromaticity correction relative to the current setpoint.

Configuration

- type: pyaml.tuning_tools.chromaticity
  name: CHROMATICITY_CORRECTION
  sextu_array_name: SEXTUPOLES
  chromaticity_monitor_name: CHROMATICITY_MONITOR
  response_matrix: path/to/chromaticity_response.json

add(dchroma, wait_time=0.0)#

Apply a chromaticity correction relative to the current setpoint.

Parameters:

dchroma (numpy.ndarray) – Horizontal and vertical chromaticity change to apply (dimensionless).
wait_time (float) – Delay in seconds after changing sextupole strengths.

correct(dchroma)#

Calculate sextupole-strength changes for a chromaticity change.

Parameters:: dchroma (numpy.ndarray) – Desired horizontal and vertical chromaticity change (dimensionless).
Returns:: numpy.ndarray – Sextupole-strength changes obtained from the response-matrix pseudoinverse, in the configured sextupole strength units (typically m^-2).
Raises:: PyAMLException – If no response matrix has been loaded or measured.
Return type:: array

get()#: Return the requested dimensionless horizontal and vertical chromaticity.

load(load_path)#

Load a chromaticity response matrix and prepare its pseudoinverse.

Parameters:: load_path (Path) – Path to the serialized ResponseMatrixData file.

readback()#: Measure and return the current dimensionless horizontal and vertical chromaticity.

set(chroma, iter=1, wait_time=0.0)#

Iteratively correct chromaticity to a requested setpoint.

Parameters:

chroma (numpy.ndarray) – Target horizontal and vertical chromaticity values (dimensionless).
iter (int) – Number of correction iterations.
wait_time (float) – Delay in seconds between correction iterations.

property chromaticity_monitor: ChromaticityMonitor#: Return the chromaticity monitor used for readback.

property response_matrix: ResponseMatrixData | None#: Return the loaded chromaticity response matrix, if available.

property sextupoles: MagnetArray#: Return the sextupole array used for correction.