What is a negative scattering length?

Positive neutron scattering length of a nucleus means repulsive potential the neutron is subject to as it approches the nuclus whereas negative scattering length means the neutron is subjected to a attractive potential of the nucleus.

What is incoherent scattering in physics?

Incoherent scattering is a type of scattering phenomenon in physics. The term is most commonly used when referring to the scattering of an electromagnetic wave (usually light or radio frequency) by random fluctuations in a gas of particles (most often electrons).

What is scattering length density?

The Scattering Length Density (SLD, sometimes denoted Nb) is a measure of the scattering power of a material. It increases with the physical density (how tightly packed the scattering entities are), as well as the intrinsic scattering power of the ‘scattering entities’.

What is scattering length in nuclear physics?

[′skad·ə·riŋ ‚leŋkth] (nuclear physics) A parameter used in analyzing nuclear scattering at low energies; as the energy of the bombarding particle becomes very small, the scattering cross section approaches that of an impenetrable sphere whose radius equals this length. Also known as scattering power.

What is the difference between incoherent and coherent scattering?

Coherent scattering depends on Q and is therefore the part that contains information about scattering structures, whereas SANS incoherent scattering is featureless (Q independent) and contains information about the material scattering density only. Here only elastic scattering is considered. 1. COHERENT AND INCOHERENT CROSS SECTIONS

Which is an example of incoherent scattering from hydrogen?

The measured incoherent scattering from hydrogen, for example, can be considerably larger (by more than 20%) than its bound value. For example, the incoherent scattering cross section of H 2 O is

Can a disorder scattering be considered a coherent scattering?

Disorder scattering (different atoms in a small molecule) could be considered as coherent (not incoherent) scattering even though it is Q-independent in the SANS range due to the smallness of the molecules. Note that in x-ray scattering, there is no equivalent for spin-incoherence and that contributions from disorder scattering are coherent.

Where can I find the scattering length density?

For energy dependent cross sections please go to the National Nuclear Data Center at Brookhaven National Lab. The neutron scattering length density is defined as:

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