E3 Triple-axis Spectrometer

The E3 spectrometer was designed as one of the 4 triple-axis spectrometers at NRU. The triple-axis spectrometers at CRL are, by design, very versatile, configurable for various types of experiments and modes of operation. As a point of historical interest, the monochromator shielding drum of E3 is built from components used in the original Brockhouse Spectrometer.

E3 is usually equipped with a 32-wire position sensitive detector. Wire spacing is 2 mm which at E3 corresponds to ~ 0.08°. The detector can also be used as a variable-width single-wire detector. The 32-wire detector can be replaced with a standard detector.

Typical Experiments

  • residual strain/stress mapping
  • crystallographic texture
  • grain-interaction stresses
  • precipitation and phase transformations
  • inelastic scattering in triple-axis mode (eg phonons, magnons, solitons, correlations)
  • elastic scattering in diffraction mode or triple-axis mode experiments (eg mapping of phase diagrams, magnetization measurements).

Ancillary Equipment Specifically Available to E3 Strain collimators:

  • A large variety of slits and height limiters are available for defining the sampling volume for residual strain/stress mapping experiments.
  • An Eulerian Cradle can be installed on E3 for full control of sample orientation. The addition of the cradle effectively transforms E3 into a 4-circle diffractometer. Primarily used for crystallographic texture and grain interaction measurements, but also useful for examination and pre-alignment of single-crystals.

Technical Specifications

Beam Size at sample position: 5 cm high × 5 cm wide (maximum)

Available monochromomators and analyzers:

  • Be, Cu, Ge, graphite, Si available (these monochromating and analyzing crystals are shared among the spectrometers, several crystals of each type are available).

Monochromator take-off Angle: Continuously variable in 3 ranges, 0 – 30°, 30 – 60°, and 60 – 91°

Specimen scattering angle: Continuously variable from 0 – 120°

Collimators:

No source to monochromator collimator is installed, effective collimation is ~ 0.6°. The remaining beam segments are soller slit adjustable with each soller channel having a minimum blade spacing of 0.050″. Soller blades are available in 5.5″, 8.0″, 14.5″ and 19″ lengths. The maximum blade length in the beam segments are:

  • monochromator to specimen, 19″
  • specimen to analyzer, 14.5″
  • analyzer to detector, 8″

Detector:

The standard configuration of E3 uses a 32-wire position sensitive detector. This detector can also be used as a variable-width single detector. When required, a true single detector can be installed.