Page 220 - Neutrons for Sciences and Society

Neutrons for Science
Model. This is not what is found120, and suggests we should advance beyond this model. This is a domain where a reactor provides information having the same impact as that from a big accelerator such as those at CERN. I can also cite the work on the measurement of the electric dipole moment of the neutron which is linked to space-time invariance.
Despite my lack of competence in this area I have cited these experiments to demonstrate that the most fundamental physics can be studied using these particles. However most of the 700
or more experiments performed each year at the ILL relate to
the determination of magnetic structures, the precise location of hydrogen atoms in organic molecules, including proteins, and the study of motion in solids and liquids.
A very good example is the study of polymer melts. De Gennes proposed a model to account for the reptation of the long polymer molecules. The model was in competition with other mechanisms, and there was no experiment to show which was the best model. Experiments using a neutron spin-echo spectrometer ruled in favour of de Gennes model121.
Overall, since the creation of the ILL, the work done there has resulted in at least 10,000 scientific publications in peer reviewed journals. [2018 addition: About 21,000 scientific publications in 50 years.] Elegant experiments have been performed on magnetic substances, which is a field where neutrons are absolutely irreplaceable. About 28% of publications treat different aspects in this field of research.
120 The value found is 0.9924 with a possible error of 0.0028, hence significantly different from 1. One can see the precision which can be achieved in some experiments.
121 D. Richter et al., Phys. Rev. Lett. (1990), 64, 1389-1392,. DOI 10.1103/PhysRevLett.64.1389 211