Chapter 9
Nuclear Hyperfine Techniques
The interaction of X-rays with electrons is so strong that we can usually ignore
nuclear effects, dismissing the nucleus as a point charge too massive and slow to
respond to the electromagnetic field of the X-ray. However, the ability to produce
bright X-ray beams with narrow linewidths now permits observation of nuclear
transitions that are normally observed with radioisotope sources. In this chapter we
first describe some very general properties of nuclear transitions and nuclear excited
states, and we then describe the conventional way of doing things. We then present
the most popular synchrotron nuclear techniques for capturing the same information.
“I am a chemist (biologist, materials scientist . . .),” you object. Why do I care
about nuclear properties? It turns out that nuclear spectroscopy can reveal a wealth of
information about:
• Electronic structure.
• Magnetic properties.
• Vibrational modes, and all of this with:
• Elemental and isotopic sensitivity for the nucleus under study.
How is this possible? It turns out that small shifts and splittings in nuclear energy
levels can report back about electronic structure and hence the chemistry of the
sample. This information is so valuable that NASA included a nuclear instrument
(a Mössbauer spectrometer) on the Rover mission to Mars (Fig. 9.1). In addition, the
motion of the nucleus can be detected by synchrotron techniques, allowing characterization of the dynamics and normal modes around that nucleus (Chap. 10).
To be specific, there are three techniques that reveal the nuclear energy levels and
hence electronic structure and magnetic properties:
• Synchrotron Mössbauer spectroscopy (SMS).
• Nuclear forward scattering (NFS), and.
• Synchrotron radiation perturbed angular correlation (SRPAC).
© Springer Nature Switzerland AG 2020
S. P. Cramer, X-Ray Spectroscopy with Synchrotron Radiation, Biological and Medical
Physics, Biomedical Engineering, https://doi.org/10.1007/978-3-030-28551-7_9
227
Nuclear Hyperfine Techniques
The interaction of X-rays with electrons is so strong that we can usually ignore
nuclear effects, dismissing the nucleus as a point charge too massive and slow to
respond to the electromagnetic field of the X-ray. However, the ability to produce
bright X-ray beams with narrow linewidths now permits observation of nuclear
transitions that are normally observed with radioisotope sources. In this chapter we
first describe some very general properties of nuclear transitions and nuclear excited
states, and we then describe the conventional way of doing things. We then present
the most popular synchrotron nuclear techniques for capturing the same information.
“I am a chemist (biologist, materials scientist . . .),” you object. Why do I care
about nuclear properties? It turns out that nuclear spectroscopy can reveal a wealth of
information about:
• Electronic structure.
• Magnetic properties.
• Vibrational modes, and all of this with:
• Elemental and isotopic sensitivity for the nucleus under study.
How is this possible? It turns out that small shifts and splittings in nuclear energy
levels can report back about electronic structure and hence the chemistry of the
sample. This information is so valuable that NASA included a nuclear instrument
(a Mössbauer spectrometer) on the Rover mission to Mars (Fig. 9.1). In addition, the
motion of the nucleus can be detected by synchrotron techniques, allowing characterization of the dynamics and normal modes around that nucleus (Chap. 10).
To be specific, there are three techniques that reveal the nuclear energy levels and
hence electronic structure and magnetic properties:
• Synchrotron Mössbauer spectroscopy (SMS).
• Nuclear forward scattering (NFS), and.
• Synchrotron radiation perturbed angular correlation (SRPAC).
© Springer Nature Switzerland AG 2020
S. P. Cramer, X-Ray Spectroscopy with Synchrotron Radiation, Biological and Medical
Physics, Biomedical Engineering, https://doi.org/10.1007/978-3-030-28551-7_9
227