Brillouin spectroscopy of protein hydration water: new experimental potentialities opened up by the thermalneutron spectrometer BRISP

Neutron Brillouin spectroscopy is a powerful tool for studying the microscopic dynamics of soft matter. At the same time, it is an intrinsically difficult technique: for this reason the collective dynamics of some complex systems is still waiting for deeper investigations. An important such case is the study of coherent collective modes in protein hydration water, a subject of major interest for both soft-matter physics and protein science. Thanks to the capabilities of the new Brillouin spectrometer BRISP, which recently became operative at the Institut Laue-Langevin (Grenoble, France), we can present here the first reliable experimental determination of the neutron Brillouin spectrum of protein hydration water.