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Neutrons for Science
Structural biology is not the only area where there is complementarity between intense X-ray and neutron sources. A review of these fields has been published by W.G. Stirling102. A good example is the determination103 of the complex magnetic structure of the compound UPtGe. Both X-rays and neutrons were needed to resolve this structural problem. An unexpected field
of complementarity is the study of phonons, hitherto reserved to neutrons. The high intensity X-ray beams can be obtained with energy resolution comparable to neutrons, and the field of phonon studies broadens to include substances where the velocity of sound is very high. Conversely it is remarkable that neutrons continue
to be useful despite the very feeble intensity of these sources. Assuming the neutron is equivalent to one photon, the brightness of the ILL neutron source is like a candle, while the brightness of the ESRF X-ray source is like hundreds of million of suns104.
7.3 The problem of schools
The accession of Britain, then later the creation of the ESRF, had made it even more important to provide children of employees
of German and British and other nationalities the opportunity
to access an education that did not handicap their return to their own country. We were aware from the creation of the ILL of the
102 W.G. Stirling “Complementarity between neutron and synchrotron X-ray scattering” in Proceedings of the sixth summer school of neutron scattering (edited by A. Furrer), Singapore World Science, (1998) ISBN 978- 981-02-3558-1, p87-108, DOI 10.1142/3870
103 D. Mannix et al, Phys. Rev., (2000), B 62, p3801-3810, DOI 10.1103/PhysRevB.62.3801 104 I am grateful to Alain Filhol for this comparison.
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