Energy-dispersive X-ray detection

Toby, B. H.

doi:10.1107/97809553602060000735

International
Tables for
Crystallography
Volume G
Definition and exchange of crystallographic data
Edited by S. R. Hall and B. McMahon

pdf | chapter contents | chapter index | related articles

International Tables for Crystallography (2006). Vol. G. ch. 3.3, p. 127

Section 3.3.8.4. Energy-dispersive X-ray detection

B. H. Toby^a ^*

^a NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8562, USA
Correspondence e-mail: brian.toby@nist.gov

3.3.8.4. Energy-dispersive X-ray detection

| top | pdf |

For energy-dispersive X-ray diffraction, an X-ray detector is placed at a fixed value of $[2\theta]$ and a diffractogram is measured on a multichannel analyser. The channel number is then calibrated to yield photon energies. From the energy and $[2\theta]$ angle, a d-spacing or Q value $[(Q = 4 \pi\sin\theta/\lambda)]$ is calculated for each diffraction point. Note that energy, d spacing or Q are not the experimental independent variable. Rather, they result from processing, since calibration information is required. The calibration equation should be described in _pd_calibration_conversion_eqn.

In Example 3.3.8.4, the nominal $[2\theta]$ setting is 6.5°, but the actual position (determined by prior calibration) is 6.6071°, so the difference is indicated using a _pd_calib_2theta_offset value (see Section 3.3.4.3).

Example 3.3.8.4. Measurements from an energy-dispersive X-ray diffraction experiment.

[Scheme scheme33]

References

International Tables for Crystallography (2006). Vol. G. ch. 3.3, p. 127