Neutron scattering backscattering

The application of neutron spin-echo spectroscopy to the analysis of the slow dynamics of biomolecules is still in its infancy, but developing fast. The few published investigations either pertain to the diffusion of globular proteins in solution [332-334] or focus on the internal subnanosecond dynamics on the length scale, <10 A as measured on wet powders [335,336]. The latter regime overlaps with other quasi-elastic neutron scattering methods as backscattering and TOE spectrometry [337-339]. 

Inelastic neutron scattering, on the other hand, usually employs a monochromatic neutron beam and records the intensity of the scattered neutron beam as a function of neutron kinetic energy. Such inelastic collision spectra are monitored as a function of the applied field and the (usually low) temperature. The observed peaks then represent the energy differences of thermally populated and excited unpopulated multiplet states. Inelastic neutron scattering experiments can be conducted using triple-axis, backscattering, or time-of-flight spectrometers. 

Rutherford backscattering spectroscopy Scanning electron microscopy Secondary ion mass spectroscopy Single crystal X-ray diffraction Small angle X-ray and neutron scattering Spark source mass spectrometry Transmission electron microscopy Voltametry... 

In contrast to TAS, time-of-flight (TOF) spectrometers and backscattering (BS) spectrometers are adapted to simultaneously record neutrons scattered into a wide range of wave vectors and energies. They are used to measure S(g,co) for liquids or disordered samples or magnetic energy spectra that vary only little with Q. A detailed review of existing instruments can be found in Ref [16]. 

Figure 7 This figure maps out the length and energy scales that are accessible with the different inelastic neutron scattering techniques. In the text, we have limited our discussion to the time-of-flight (TOF) spectrometers, backscattering (BS) spectrometers, and spin echo spectrometers.

The Disk Chopper and Backscattering spectrometers, like most other inelastic neutron spectrometers, measure the scattering function S(Q,w), where Q is the wave-vector transfer and w is the energy transfer of the scattering. The scattering function is the Fourier transform (in both time and length) of the... 

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