MLZ is a cooperation between:
> Technische Universität München
> Helmholtz-Zentrum Hereon
> Forschungszentrum Jülich
MLZ is a member of:
> LENS
> ERF-AISBL
MLZ on social media:
MLZ (eng)
Lichtenbergstr.1
85748 Garching
KWS-2
Small angle scattering diffractometer
This instrument is focussed on cold neutrons. All parameters given here are valid during the current operation of FRM II. Please get in touch with the instrument team well in advance for all further details (length of experiment etc.).
KWS-2 [1] is a classic small-angle scattering diffractometer at which a large Q range between 2.0 · 10-3 and 1.0 Å-1 can be examined using the pinhole camera principle with different neutron wavelengths and detection distances (gallery, fig. 1,2). The instrument is dedicated to the investigation of mesoscopic structures and structural changes due to the fast kinetic processes in the fields of soft matter, chemistry and biology [2]. The instrument resolution is set by the mechanical monochromator (velocity selector) to either Δλ/λ = 10 % (in the non-inclined configuration) or Δλ/λ = 20 % (in the inclined configuration) [3,4]. The resolution can further be set between 2 % and 10 % by using the main double-disk chopper with adjustable opening windows [5] (gallery, fig. 2, 3). The new large-area detection system with fast readout electronics [6] allows new ways of increasing performance, including high-intensity/ small background measurements (when using the secondary one-disk chopper) [7].
Finally, the ability to use the mechanical monochromator in an inclined position with respect to the beam axis (gallery, fig. 4) offers the availability of thermal neutrons (λ = 2.8 Å) at the instrument. The neutron flux at the sample position (gallery, fig. 5) varies with the wavelength and the wavelength resolution, i.e. with the setting of the velocity selector. (gallery, fig. 4-6)
[1] A. Radulescu et al., J. Phys. Conf. Series 351, 012026 (2012)
[2] A. Radulescu et al., J. Vis. Exp. 118, e54639 (2016), KWS-2 film
[3] A. Radulescu, Ioffe, A., Nucl. Inst. Meth. A, 586 , 55 (2008)
[4] A. Radulescu et al., Nucl. Inst. Meth. A 689, 1 (2012)
[5] A. Radulescu et al., J. Appl. Cryst. 48, 1860 (2015)
[6] J. Houston et al., J. Appl. Cryst. 51, 323 (2018)
[7] L. Balacescu et al., J. Appl. Cryst. 54, 1217 (2021)
- Colloids, nanocomposites, polymer gels, networks
- Polymer blends, diblock copolymers
- Microemulsions, complex fluids, micelles
- Membranes, films; in-situ adsorption – desorption/ humidifying – drying phenomena
- Shear induced micelle deformation, rubber network deformation, nanocomposite ordering
- In-situ crystallisation semi-crystalline polymer
- Nanoparticles for drug delivery and vaccines
- Anton-Paar fluid rheometer
- Stopped flow device
- Cuvettes holders: 9 horizontal x 3 vertical (temperature controlled) for standard Hellma Cuvettes 404.000-QX and 110-QX
- Oil & water thermostats (typical 10 …100°C)
- 8-positions and 2 × 6 positions thermostated (Peltier) sample holder (-40°C … 150°C)
- Humidity chamber, 5 % … 95 % for 10°C … 60°C
- Stretching apparatus (4 devices in a common set-up) for controlled stretching in beam
- FT-IR spectroscopy
- DLS & SLS
- 3He spin analyser (SEOP)
- SEC-SANS (soon)
- Q = 0.002… 1 Å-1 (gallery, fig. 2)
- Flux
- 8 · 106 n cm-2 s-1 for λ= 2.88 Å
- 1.9 · 107 n cm-2 s-1 for λ= 5.0 Å (gallery, fig. 5,6)
- Astrium, Δλ/λ = 20 % (tilted selector), λ = 2.8… 7 Å
- Δλ/λ = 10 % on request (lower flux)
- Tunable Δλ/λ: 20 %… 2 % (TOF analysis) (gallery, fig. 3)
- 2 m, 4 m, 8 m, 14 m, 20 m, sample position
- Rectangular 1 × 1 mm2 – 50 × 50 mm2
- XYZθ translational-rotational stage + cradle
- Accuracy better than 0.01°, 0.01 mm
- Robot with multiple positions cuvette carousel (soon)
- 1-disc with 4 opening windows (1 cm x 1 cm), frequency 10 – 45 Hz
- TOF data acquisition in the high-Q regime (1 – 4 m detection distance)
- separation of the inelastic and elastic scattering from the hydrocarbon systems
- Detection range: continuous 1 – 20 m
- 3He tubes array
- active area ~0.9 m2
- count rate for no deadtime > 2 MHz
- resolution = < 8 mm
- efficiency 88 % for 5 Å, 75 % for 2.8 Å
- semi-transparent beamstop, simultaneous measurement of transmission and scattering
Instrument Scientists
Dr. Aurel Radulescu
Phone: +49 (0)89 158860-712
E-Mail: a.radulescu@fz-juelich.de
Dr. Jia-Jhen Kang
Phone: +49 (0)89 158860-739
E-Mail: j.kang@fz-juelich.de
Dr. Marie-Sousai Appavou
Phone: +49 (0)89 158860-747
E-Mail: m.s.appavou@fz-juelich.de
KWS-2
Phone: +49 (0)89 158860-510
Operated by
News
Film: Roboter changes samples
Publications
Find the latest publications regarding KWS-2 in our publication database iMPULSE:
Citation of the instrument
Heinz Maier-Leibnitz Zentrum. (2015). KWS-2: Small angle scattering diffractometer. Journal of large-scale research facilities, 1, A29. http://dx.doi.org/10.17815/jlsrf-1-27
For citation please always include the DOI.
Gallery
MLZ is a cooperation between:
> Technische Universität München> Helmholtz-Zentrum Hereon
> Forschungszentrum Jülich
MLZ is a member of:
> LENS> ERF-AISBL
MLZ on social media: