Performance of neutron resonance spin-echo in biology

In 1995, the construction of a medium wave vector spinecho spectrometer MUSES started at the guide Glbis of the Orphée reactor. This new instrument was a joint venture between TU München and LLB. The first echo was reported in 1996 [l]. In 1998, it was the first spectrometer using the neutron resonance principle (NRSE) [2] for spin-echo measurements to be open to external users[3]. Since that time, there were several attempts to use it in the field of dynamics of biological systems. We report here on two different studies dealing, on one hand, with the diffusion mechanisms of proteins in concentrated solutions and, on the other hand, with internal dynamics in proteins.