Spectrometer framework

A framework for the implementation of the various spectrometers assemblies found on beamlines. This framework is designed for spectrometers that are made of a set of crystal analysers and a 2D detector.

The Spectrometer class manages one detector and a set of analysers and provides 2 pseudo-axes to drive the system Energy or Bragg position. Each analyser has its own crystal and can be driven independently in Energy or Bragg position. A detector has a target analyser and its Energy or Bragg position is bound to its target position.

For the standard Cartesian and Cylindrical geometries, users can declare their own setup through the YAML configuration file. The geometry kind is defined by the real axes dependency of the analysers and detector mounting. For example, the Cartesian geometry assume that an analyser depends on 4 real axes [‘xpos’, ‘zpos’, ‘pitch’, ‘yaw’] and the detector on 3 real axes[‘xpos’, ‘zpos’, ‘pitch’].

YML Configuration

analysers:

  - name: ana_0
    plugin: generic
    module: spectrometers.spectro_base
    class: CylindricalAnalyser
    miscut: -5.04931
    radius: 500
    angular_offset: 0
    offset_on_detector: 0
    bragg_low_limit: 25   # optional (default=15)
    bragg_high_limit: 88  # optional (default=89)
    xtals:
      - xtal: Si844
        dspacing: 0.5543013043019761  # dspacing * 1e-10
    real_axes:
      - rpos: $xa0
      - zpos: $za0
      - pitch: $pita0
      - yaw: $yawa0

    energy_axis:           # optional
      - name: ene_ana_0    # optional
    bragg_axis:            # optional
      - name: bragg_ana_0  # optional

  - name: ana_1
    plugin: generic
    module: spectrometers.spectro_base
    class: CylindricalAnalyser
    miscut: -5.04931
    radius: 500
    angular_offset:  -3.5
    offset_on_detector: 14
    bragg_low_limit: 25   # optional (default=15)
    bragg_high_limit: 88  # optional (default=89)
    xtals:
      - xtal: Si844
        dspacing: 0.5543013043019761  # dspacing * 1e-10
    real_axes:
      - rpos: $xa1
      - zpos: $za1
      - pitch: $pita1
      - yaw: $yawa1
    energy_axis:           # optional
      - name: ene_ana_1    # optional
    bragg_axis:            # optional
      - name: bragg_ana_1  # optional

  - name: ana_2
    plugin: generic
    module: spectrometers.spectro_base
    class: CylindricalAnalyser
    miscut: -5.04931
    radius: 500
    angular_offset: 3.5
    offset_on_detector: -14
    bragg_low_limit: 25   # optional (default=15)
    bragg_high_limit: 88  # optional (default=89)
    xtals:
      - xtal: Si844
        dspacing: 0.5543013043019761  # dspacing * 1e-10
    real_axes:
      - rpos: $xa2
      - zpos: $za2
      - pitch: $pita2
      - yaw: $yawa2
    energy_axis:           # optional
      - name: ene_ana_2    # optional
    bragg_axis:            # optional
      - name: bragg_ana_2  # optional


detectors:

  - name: det_0
    plugin: generic
    module: spectrometers.spectro_base
    class: Detector
    target: $ana_0
    width: 400
    height: 200
    bragg_low_limit: 25   # optional (default=15)
    bragg_high_limit: 88  # optional (default=89)
    real_axes:
      - xpos: $xdet
      - zpos: $zdet
      - pitch: $pitdet
    energy_axis:           # optional
      - name: ene_det_0    # optional
    bragg_axis:            # optional
      - name: bragg_det_0  # optional


spectrometers:

  - name: spectro
    plugin: generic
    module: spectrometers.spectro_base
    class: Spectrometer
    bragg_low_limit: 25   # optional (default=15)
    bragg_high_limit: 88  # optional (default=89)
    detector: $det_0
    analysers:
      - name: $ana_0
      - name: $ana_1
      - name: $ana_2
      - name: $ana_3
      - name: $ana_4
    energy_axis:
      - name: ene_spectro    # optional
    bragg_axis:
      - name: bragg_spectro  # optional

For none-standard geometries, users can inherit from the base classes Detector, Analyser, Spectrometer and overload the compute_bragg_solution and _get_pos methods of the Detector and Analyser class (as an example see the mmspectro.py file). The main difference with the standard geometries is the real axes on which depend the analysers and detector.

analysers:
  - name: ana_0_mm
    plugin: generic
    module: spectrometers.mmspectro
    class: MMAnalyser
    miscut: 0
    radius: 500
    ypos: 0
    offset_on_detector: 0
    bragg_low_limit: 25   # optional (default=15)
    bragg_high_limit: 88  # optional (default=89)
    xtals:
      - xtal: Si444
        dspacing: 0.783882894235
      - xtal: Si844
        dspacing: 0.5543013043019761  # dspacing * 1e-10
    real_axes:
      - xpos: $xa0mm
      - zpos: $za0mm
      - theta: $pita0mm
      - chi: $yawa0mm
    energy_axis:           # optional
      - name: ene_ana_0_mm   # optional
    bragg_axis:            # optional
      - name: bragg_ana_0_mm  # optional

  - name: ana_1_mm
    plugin: generic
    module: spectrometers.mmspectro
    class: MMAnalyser
    miscut: 0
    radius: 500
    ypos: -120
    offset_on_detector: 0 
    bragg_low_limit: 25   # optional (default=15)
    bragg_high_limit: 88  # optional (default=89)
    xtals:
      - xtal: Si444
        dspacing: 0.783882894235
      - xtal: Si844
        dspacing: 0.5543013043019761  # dspacing * 1e-10
      - xtal: Si555
        dspacing: 0.627106315
    real_axes:
      - xpos: $xa1mm
      - zpos: $za1mm
      - theta: $pita1mm
      - chi: $yawa1mm
    energy_axis:           # optional
      - name: ene_ana_1_mm    # optional
    bragg_axis:            # optional
      - name: bragg_ana_1_mm  # optional

  - name: ana_2_mm
    plugin: generic
    module: spectrometers.mmspectro
    class: MMAnalyser
    miscut: 0
    radius: 500
    ypos: 120
    offset_on_detector: 0 
    bragg_low_limit: 25   # optional (default=15)
    bragg_high_limit: 88  # optional (default=89)
    xtals:
      - xtal: Si444
        dspacing: 0.783882894235
      - xtal: Si844
        dspacing: 0.5543013043019761  # dspacing * 1e-10
    real_axes:
      - xpos: $xa2mm
      - zpos: $za2mm
      - theta: $pita2mm
      - chi: $yawa2mm
    energy_axis:           # optional
      - name: ene_ana_2_mm    # optional
    bragg_axis:            # optional
      - name: bragg_ana_2_mm  # optional


detectors:
  - name: det_0_mm
    plugin: generic
    module: spectrometers.mmspectro
    class: MMDetector
    target: $ana_0_mm
    width: 400
    height: 200
    bragg_low_limit: 25   # optional (default=15)
    bragg_high_limit: 88  # optional (default=89)
    real_axes:
      - dx: $xdetmm
      - dz: $zdetmm
      - dth: $pitdetmm
      - dlong: $dlong
      - azlong: $azlong
    energy_axis:           # optional
      - name: ene_det_0_mm    # optional
    bragg_axis:            # optional
      - name: bragg_det_0_mm  # optional


spectrometers:
  - name: spectro_mm
    plugin: generic
    module: spectrometers.mmspectro
    class: MMSpectrometer
    bragg_low_limit: 25   # optional (default=15)
    bragg_high_limit: 88  # optional (default=89)
    detector: $det_0_mm
    analysers:
      - name: $ana_0_mm
      - name: $ana_1_mm
      - name: $ana_2_mm
    energy_axis:
      - name: ene_spectro_mm    # optional
    bragg_axis:
      - name: bragg_spectro_mm  # optional