Contrast factor for neutrons

Z(9) differential scattering cross section per volume unit K contrast factor for neutron scattering... 

Now we have to use the contrast factor for neutron scattering, denoted ATn, and it is given by... 

Since scattering factors for neutron diffiaction are independent of the scattering angle (in contrast to the case of XRD and ED), neutron diffraction data are more frequently used for refinement than the others. 

In contrast to X rays, the scattering factors for neutrons are not proportional to atomic number. Whereas X rays... 

Small angle neutron scattering measurements were carried out with the PACE diffractometer at the Laboratoire Leon Brillouin, (CE Saclay, France). The q range observed was 3.4 lO" to 0.2 A l. Samples were prepared in deuterated instead of ordinary water to achieve a suitable value for the neutron contrast factor. 

The choice of the most appropriate scattering technique depends upon two main requirements the contrast factor and/or the need for time-resolved experiments. Presently, time-resolved experiments can be essentially carried out with X-rays thanks to the extremely high flux of photons delivered by synchrotron radiation facilities. In some high flux neutron facilities, such as ILL in Grenoble, some apparatuses allow one to do near-time-resolved experiments under certain experimental setup conditions (low sample-detector distances). 

S A N S can be employed to study both homogeneous as well as heterogenous blends and various information can be derived by analysis of the differential scattering cross-section, d2(Q)/dQ (cm ), where d2(Q) (neutron s ) is the number of neutrons scattered per second into a small solid angle, dQ. The measured intensity, I Q), is related to d 2(Q)/d Q and depends on various parameters such as the incident flux, resolution of the detector, detector efficiency, and so on. It is also a function of the contrast factor (Ag), which is defined as the square of the difference of the scattering length density of the scattering centers, for example, the particle and the matrix. This quantity is calculated from ... 

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