The Couette configuration of the Los Alamos Neutron Science Center neutron rheometer for the investigation of polymers in the bulk via small-angle neutron scattering.

A neutron rheometer in the Couette geometry has been built at the Los Alamos Neutron Science Center to examine the molecular steady-state and dynamic responses of entangled polymeric materials in the bulk under the application of shear stress via small-angle neutron scattering. Although similar neutron rheometers have been fabricated elsewhere, this new design operates under the extreme conditions required for measuring the structure and behavior of high molecular weight polymer melts. Specifically, the rheometer achieves high torques (200 N m) and shear rates (865 s(-1)) simultaneously, never before attainable with other neutron rheometers at temperatures up to 240 degrees C under an inert gas environment.