Mgd. Vandergrinten et al., DYNAMIC PROTON POLARIZATION ON POLYMERS IN SOLUTION - CREATING CONTRAST IN NEUTRON-SCATTERING, Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment, 356(2-3), 1995, pp. 422-431
Dynamic nuclear polarisation (DNP) as an alternative or additional met
hod to create contrast in neutron small angle scattering has been inve
stigated with emphasis on the study of polymers in solution, The need
for high polarisations imposes specific requirements on the sample and
its environment. Vitreous beads have been used as samples. Nuclear re
laxation times show that they contain dissolved air. Parasitic scatter
ing from the solvent is observed, probably arising from nanometer air
bubbles. DNP is shown to be useful, in particular for samples that con
sist of mixtures of hydrogen-free and hydrogen-rich molecules, where t
he different molecules can be highlighted by changing the polarisation
.