Large scales-long times: Adding high energy resolution to SANS

The Neutron Spin Echo (NSE) variant MIEZE (Modulation of IntEnsity by Zero Effort), where all beam manipulations are performed before the sample position, offers the possibility to perform low background SANS measurements in strong magnetic fields and depolarising samples. However, MIEZE is sensitive to differences Delta L in the length of neutron flight paths through the instrument and the sample. In this article, we discuss the major influence of Delta L on contrast reduction of MIEZE measurements and its minimisation. Finally we present a design case for enhancing a small-angle neutron scattering (SANS) instrument at the planned European Spallation Source (ESS) in Lund, Sweden, using a combination of MIEZE and other TOF options, such as TISANE offering time windows from ns to minutes. The proposed instrument would allow obtaining an excellent energy- and Q-resolution straightforward to mu s for 0.01 angstrom(-1), even in magnetic fields, depolarising samples as they occur in soft matter and magnetism while keeping the instrumental effort and costs low. (C) 2011 Elsevier B.V. All rights reserved.