MPES: new concepts from NIAC discussions, searchable fields

[lukaspie]

• Explicitly name the following axes in NXmpes/NXentry/data(NXdata):

  • energy
  • photon energy
  • kx, ky, kz
  • k_parallel, k_perpendicular
  • angular0, angular1
  • spatial0,spatial1
  • delay
  • temperature

• Explicitly name the following axes in NXmpes/NXinstrument/NXelectronanalyser/NXdetector/raw_data(NXdata):

  • pixel_x, pixel_y
  • photon energy
  • kx, ky, kz
  • k_parallel, k_perpendicular
  • angular0, angular1
  • spatial0,spatial1
  • delay
  • temperature

• NXprocess and subclasses are stored directly under Nxmpes/NXentry

  • AXIS_calibration for general calibration on all axes that are defined in NXdata
  • Brought in special calibrations from existing base class NXprocess_mpes

• As a consequence, remove base classes NXdata_mpes , NXdata_mpes_detector, and NXprocess_mpes

• Allow for multiple beams and sources

  • beam_probe/source_probe
  • beam_pump/source_probe
  • beamTYPE/sourceTYPE -> I still think this is valuable, see the description in its docs

• Mention the following terms as optional in the application definition:

  • additionally: search for terms defined in base classes that are not yet mentioned in app def -> optional?

• change all instances of NXidentifier to fields inheriting from instanceNAME

• remove NXsubstance, use existing concepts in NXsample for now

  • use NXsample/chemical_formula

• add field core_level under ENTRY

• list like NXdata/@axes

• suggested enumeration of all possible core levels

Open questions:

• Do we need k_parallel, k_perpendicular?
• Is AXIS_calibration good enough or do we need individual named calibrations for each axis?