title: Studying Soft-matter and Biological Systems over a Wide Length-scale from Nanometer and Micrometer Sizes at the Small-angle Neutron Diffractometer KWS-2.
abstract: The KWS-2 SANS diffractometer is dedicated to the investigation of soft matter and biophysical systems covering a wide length scale, from nm to µm. The instrument is optimized for the exploration of the wide momentum transfer Q range between 1x10-4and 0.5 Å-1by combining classical pinhole, focusing (with lenses), and time-of-flight (with chopper) methods, while simultaneously providing high-neutron intensities with an adjustable resolution. Because of its ability to adjust the intensity and the resolution within wide limits during the experiment, combined with the possibility to equip specific sample environments and ancillary devices, the KWS-2 shows a high versatility in addressing the broad range of structural and morphological studies in the field. Equilibrium structures can be studied in static measurements, while dynamic and kinetic processes can be investigated over time scales between minutes to tens of milliseconds with time-resolved approaches. Typical systems that are investigated with the KWS-2 cover the range from complex, hierarchical systems that exhibit multiple structural levels (e.g., gels, networks, or macro-aggregates) to small and poorly-scattering systems (e.g., single polymers or proteins in solution). The recent upgrade of the detection system, which enables the detection of count rates in the MHz range, opens new opportunities to study even very small biological morphologies in buffer solution with weak scattering signals close to the buffer scattering level at high Q. In this paper, we provide a protocol to investigate samples with characteristic size levels spanning a wide length scale and exhibiting ordering in the mesoscale structure using KWS-2. We present in detail how to use the multiple working modes that are offered by the instrument and the level of performance that is achieved.
authors.affiliation: Jülich Centre for Neutron Science Outstation at MLZ, Forschungszentrum Jülich GmbH; a.radulescu@fz-juelich.de.
authors.forename: Aurel
authors.initials: A
authors.lastname: Radulescu
authors.affiliation: Jülich Centre for Neutron Science Outstation at MLZ, Forschungszentrum Jülich GmbH.
authors.forename: Noemi Kinga
authors.initials: NK
authors.lastname: Szekely
authors.affiliation: Jülich Centre for Neutron Science Outstation at MLZ, Forschungszentrum Jülich GmbH.
authors.forename: Marie-Sousai
authors.initials: MS
authors.lastname: Appavou
authors.affiliation: Jülich Centre for Neutron Science Outstation at MLZ, Forschungszentrum Jülich GmbH.
authors.forename: Vitaliy
authors.initials: V
authors.lastname: Pipich
authors.affiliation: Jülich Centre for Neutron Science Outstation at MLZ, Forschungszentrum Jülich GmbH.
authors.forename: Thomas
authors.initials: T
authors.lastname: Kohnke
authors.affiliation: Jülich Centre for Neutron Science Outstation at MLZ, Forschungszentrum Jülich GmbH.
authors.forename: Vladimir
authors.initials: V
authors.lastname: Ossovyi
authors.affiliation: Jülich Centre for Neutron Science Outstation at MLZ, Forschungszentrum Jülich GmbH.
authors.forename: Simon
authors.initials: S
authors.lastname: Staringer
authors.affiliation: Department of Chemistry, Louisiana State University.
authors.forename: Gerald J
authors.initials: GJ
authors.lastname: Schneider
authors.affiliation: Jülich Centre for Neutron Science JCNS-1 & Institute of Complex Systems ICS-1, Forschungszentrum Jülich GmbH.
authors.forename: Matthias
authors.initials: M
authors.lastname: Amann
authors.affiliation: Jülich Centre for Neutron Science JCNS-1 & Institute of Complex Systems ICS-1, Forschungszentrum Jülich GmbH.
authors.forename: Bo
authors.initials: B
authors.lastname: Zhang-Haagen
authors.affiliation: Jülich Centre for Neutron Science Outstation at MLZ, Forschungszentrum Jülich GmbH.
authors.forename: Georg
authors.initials: G
authors.lastname: Brandl
authors.affiliation: Central Institute of Engineering, Electronics and Analytics - Electronic Systems (ZEA-2), Forschungszentrum Jülich GmbH.
authors.forename: Matthias
authors.initials: M
authors.lastname: Drochner
authors.affiliation: Central Institute of Engineering, Electronics and Analytics - Electronic Systems (ZEA-2), Forschungszentrum Jülich GmbH.
authors.forename: Ralf
authors.initials: R
authors.lastname: Engels
authors.affiliation: Central Institute of Engineering, Electronics and Analytics - Engineering and Technology (ZEA-1), Forschungszentrum Jülich GmbH.
authors.forename: Romuald
authors.initials: R
authors.lastname: Hanslik
authors.affiliation: Jülich Centre for Neutron Science Outstation at MLZ, Forschungszentrum Jülich GmbH.
authors.forename: Günter
authors.initials: G
authors.lastname: Kemmerling
mesh_terms: D005782:Gels / Q000737:chemistry; D033363:Neutron Diffraction / Q000379:methods*; D009502:Neutrons; D011108:Polymers / Q000737:chemistry; D011506:Proteins / Q000737:chemistry
chemical_list: D005782:Gels; D011108:Polymers; D011506:Proteins