Journal of large-scale research facilities, 1, A10 (2015) http://dx.doi.org/10.17815/jlsrf-1-32 Published: 18.08.2015 SANS-1: Small angle neutron scattering Heinz Maier-Leibnitz Zentrum Helmholtz-Zentrum Geesthacht, German Engineering Materials Science Centre Technische Universität München Instrument Scientists: - André Heinemann, German Engineering Materials Science Centre (GEMS) at Heinz Maier-Leibnitz Zentrum (MLZ), Helmholtz-Zentrum Geesthacht GmbH, Garching, Germany, phone: +49(0) 89 289 14534, email: andre.heinemann@hzg.de - Sebastian Mühlbauer, Heinz Maier-Leibnitz Zentrum (MLZ), Technische Universität München, Garching, Germany, phone: +49(0) 89 289 10784, email: sebastian.muehlbauer@frm2.tum.de Abstract: The new small angle scattering instrument SANS-1, jointly operated by the Technische Uni- versität München and GEMS, Helmholtz-Zentrum Geesthacht, has completed commissioning and is in regular user service (Gilles et al., 2006). SANS-1 is located at the end of neutron guide NL4a in the Neutron Guide Hall West. 1 Introduction SANS-1 is a standard pinhole SANS instrument with both 20 m collimation distance and 20 m sample detector distance, respectively. SANS-1 has been optimised by Monte-Carlo simulations to �t the re- strictions in both available space and optimal usage of the provided neutron beam (Gilles et al., 2007). A vertical S-shaped neutron guide with extreme suppression of fast background neutrons is optimised for complementary wavelength packages, followed by the selector tower with two selectors for high and low resolution, respectively. Adjacent to the selector tower, a collimation system with four parallel horizontal tracks provides vast �exibility: The �rst track is occupied by a neutron guide system, the second track carries the collimation system with additional background apertures on track three. One track remains empty for various future applications such as focussing lenses or a longitudinal spin echo option. Two Fe/Si transmission polarisers have been optimised to cover the whole wavelength band from 4.5 – 30 Å. The acentric mounting of the detector tube with around 2.4 m inner diameter allows to use a primary detector of 1 x 1 m2 with lateral movement of more than 0.5 m, signi�cantly expanding the accessible Q-range to around Qmax ≈ 1 Å-1. The primary detector is made up of an array of 128 position sensitive 1 http://jlsrf.org/ http://dx.doi.org/10.17815/jlsrf-1-32 https://creativecommons.org/licenses/by/4.0/ Journal of large-scale research facilities, 1, A10 (2015) http://dx.doi.org/10.17815/jlsrf-1-32 Figure 1: Instrument SANS-1 (Copyright by W. Schürmann, TUM). tubes to provide 8 mm x 8 mm spatial resolution. A second high resolution (3 mm) detector, installed downstream of the primary detector is foreseen for 2016. A TISANE chopper disk set-up will be available in 2015 which allows to perform kinetic neutron scat- tering experiments in the µs regime and simultaneously sets the stage for a later upgrade to a complete time-of-�ight option for SANS-1. 2 Typical Applications The instrument SANS-1 is dedicated to study the structure of materials on length scales of 10 to 3000 Å. With its polarised beam option, the �exible sample goniometer, the wide non-magnetic sample space and the specialised set of sample environment, SANS-1 is particularly adapted for the needs of mate- rials research and magnetism. The precise sample goniometer carries various loads up to 750 kg and ful�lls the rising demand on di�raction experiments at low scattering angles, for instance for studies of superconducting vortex lattices and other large magnetically ordered systems. • Precipitates and segregation in alloys • Chemical aggregation • Defects in materials, surfactants, colloids • Ferromagnetic correlations in magnetism • Magnetic domains • Polymers, proteins, biological membranes, viruses, ribosomes and macromolecules • Superconducting vortex lattices • Large magnetic structures such as helical magnets and skyrmion lattices 3 Sample Environment • Standard sample changer with 22 positions • Di�erent types of high temperature furnaces up to 1900°C • Deformation-rig with heating • Set of magnets (5 T horizontal, parallel and perpendicular access, 7.5 T vertical) • Sample changer with thermostat (-20 +200 °C), 11 positions • Di�erent cryostats with optional 3He insert (460 mK base temp. with 5 T magnet, 50 mK with 7.5 T magnet) • Polarisation analysis with 3He cell 2 http://dx.doi.org/10.17815/jlsrf-1-32 https://creativecommons.org/licenses/by/4.0/ http://dx.doi.org/10.17815/jlsrf-1-32 Journal of large-scale research facilities, 1, A10 (2015) Figure 2: Schematic drawing of SANS-1. 4 Technical Data 4.1 Primary beam • S-shaped neutron guide (NL 4a), 50 x 50 mm2 • Mechanical velocity selectors with variable speed 1) ∆λ /λ = 10 % medium resolution 2) ∆λ /λ = 6 % high resolution • Wavelength range: 4.5 Å – 30 Å • TISANE chopper setup with µs time resolution 4.2 Polarisation • Two V-shaped polarisers 4.3 Collimation system (source-to-sample distance) • 1 m, 2 m, 4 m, 8 m, 12 m, 16 m to 20 m in steps via insertion of neutron guide sections 4.4 Sample size • 0 – 50 mm diameter 4.5 Q-range • 0.0005 Å-1 < Q < 1 Å-1 with primary detector • Qmin= 0.0001 Å-1 with secondary high resolution detector 4.6 Detectors • Primary detector: Array of 128 3He position sensitive tubes with an active area of 1000 x 1020 mm2 and 8 mm resolution. Lateral detector movement up to 0.5 m, counting rate capability up 1 MHz. • Secondary high resolution detector (3 mm) and an active area of 500 x 500 mm2 to be installed 2016. 3 http://dx.doi.org/10.17815/jlsrf-1-32 https://creativecommons.org/licenses/by/4.0/ Journal of large-scale research facilities, 1, A10 (2015) http://dx.doi.org/10.17815/jlsrf-1-32 References Gilles, R., Ostermann, A., & Petry, W. (2007). Monte Carlo simulations of the new small-angle neutron scattering instrument SANS-1 at the Heinz Maier-Leibnitz Forschungsneutronenquelle. Journal of Applied Crystallography, 40(1), 428-432. http://dx.doi.org/10.1107/S0021889807006310 Gilles, R., Ostermann, A., Schanzer, C., Krimmer, B., & Petry, W. (2006). The concept of the new small-angle scattering instrument SANS-1 at the FRM-II. Physica B: Condensed Matter, 385-386, Part 2, 1174 - 1176. (Proceedings of the Eighth International Conference on Neutron Scattering) http://dx.doi.org/10.1016/j.physb.2006.05.403 4 http://dx.doi.org/10.17815/jlsrf-1-32 http://dx.doi.org/10.1107/S0021889807006310 http://dx.doi.org/10.1016/j.physb.2006.05.403 https://creativecommons.org/licenses/by/4.0/ Introduction Typical Applications Sample Environment Technical Data Primary beam Polarisation Collimation system (source-to-sample distance) Sample size Q-range Detectors