A new pulsed-source spectrometer has been used to measure quasi-elasti
c neutron scattering from agarose-H2O gels with high resolution in bot
h energy and momentum. Line broadenings between 3 and 300 mueV were an
alysed to quantify the dynamic structuring of water contained by a ran
dom network of hydrophilic fibres as a function of polymer concentrati
on (1-20%) and temperature (263-325 K). The results throw light on the
nature of biological water, provide new benchmarks for molecular-dyna
mics simulations, and show that a distribution of proton jump distance
s can be obtained by direct Fourier inversion of experimental data.