Research and infrastructure for neutron scattering

Neutron scattering offers unique information in materials science. This is related to the high penetration power of neutrons for many engineering materials as well as the sensitivity to light elements and magnetic induction. Moreover, the low energy (thermal) of neutrons makes them really non-destructive and allows to study slow dynamics, for example vibrational spectroscopy, rotational tunnelling, phonons and magnons as well as diffusion of single molecules. In our research we apply neutron scattering methods to scientific challenges in the areas of magnetic materials, hydrogen in materials and soft matter.

We are actively engaged in method and instrument development and operate the neutron reflectometer Super ADAM at the Institut Laue-Langevin in Grenoble, France.

Photo of Super ADAM. The picture shows a laboratory with many scientific instruments standing in a rack. Super ADAM looks like a large pipe resting on top of the rack. To the left a second, smaller rack with more instrumentation is visible. There are a lot of cables.

Super ADAM at the Institut Laue-Langevin.

Super ADAM is a neutron reflectometer operated as a national research infrastructure at the Institut Laue-Langevin (ILL) in Grenoble, France. The overall goal of the Super ADAM project is to provide state-of-the-art neutron reflectivity to the Swedish research community. Thanks to a major upgrade started in 2013, the instrument now has crucial features required to meet contemporary challenges in reflectometry. The high-resolution option of Super ADAM provides a highly polarized (up to 99.8 %) monochromatic neutron beam. This mode is complemented with polarization analysis for specular and off-specular scattering, and it is very well suited for investigations of magnetic thin films and multilayers. Super ADAM is therefore used to investigate among others lateral domain formations, magnetic behaviour of nanoparticles and dynamics in artificially patterned magnetic media.

A typical sample size is of the order 2×2 cm2, and film thicknesses between below 1 nm and up to hundreds of nanometres are studied. The standard sample environment is a He-flow cryostat combined with an electromagnet providing temperatures down to 2.5 K and magnetic fields of up to 1.1 T. Under these conditions, measurements of two spin states take around 3-4 hours with resulting data covering 5-6 orders of reflectivity. With a higher unpolarized flux, experiments on solid-liquid interfaces can be performed as well. Recently, we have installed a second instrument branch, which allows for parallel measurements with two instruments and doubles the capacity of the beam line. The second branch, shown to the left in the photo, is optimised for surface diffraction and quick measurements with high neutron flux. For experimental conditions (temperatures, magnetic fields etc.) not reachable with our own equipment we have access to full suite of ILL sample environments. More information on the instrument can be found on the webpage of the ILL.

Super ADAM is operated by Uppsala University and financed by the Swedish Research Council. It is run within the framework of Cooperative Research Groups, the group of instruments located at ILL but owned by external institutions. Currently, 30 % of the beamtime is allocated according to decisions made by the ILL scientific committees (= ILL beamtime), while the remaining 70 % is distributed among Swedish researchers in a competitive beamtime application process.

Super ADAM also hosts a number of educational efforts, trainings and outreach activities aimed to promote neutron research within the Swedish research community and to train the “next generation” of scientists. We support new users through the whole process from discussing initial ideas over writing a beam time proposal, doing the measurement, analysing the data to eventually writing a manuscript. We are very effective in this respect which is demonstrated by the significant growth of the user community since the instrument was taken over by Sweden.

Currently, the European Spallation Source (ESS) is being built just outside Lund, Sweden. This facility will offer neutron beams of unprecedented brilliance and enable completely new types of experiments. We are involved in several instrument projects at ESS. One such project comprises the development of surface scattering methods, in particular grazing-incidence small-angle neutron scattering (GISANS). Our contributions range from the implementation of specific instrument components like Port-GISANS, a portable adapter for small-angle scattering beamlines, together with the SKADI team to the design of a complete beamline. SAGA may be built at ESS in the future. Furthermore, we work on the optimisation of neutron measurements by using magnetic reference layers and the implementation of data processing procedures to study kinetic processes on the millisecond time scale.

A drawback of centralised facilities for neutron scattering is their limited availability. Even though the ESS will enable new top end research, it will not provide sufficient capacity for the needs of the whole user community. To bridge this gap, we are engaged in designing a local compact neutron source in Uppsala, that will enable complementary research and has a low access barrier, in particular for industry. Due to the recent developments of accelerator technologies, such facilities are expected to offer good neutron brilliance at much smaller size and cost than a facility such as ESS.

Here you find a collection of software packages related to neutron and X-ray reflectivity experiments that are developed and maintained by us.

Software for rebinning of neutron surface scattering data (specular and off-specular reflectivity) into Q-space

Download from Google drive

Article reference:

Överlåtaren: a fast way to transfer and orthogonalize two-dimensional off-specular reflectivity data
F. Adlmann, G. K. Pálsson, J.-C. Bilheux, J. F. Ankner, P. Gutfreund, M. Kawecki, M. Wolff
J. Appl. Cryst. 2016, 49(6), 2091-2099

GenX: Fitting software for neutron and x-ray reflectivity experiments

Download from GitHub

Article reference:

GenX 3: the latest generation of an established tool
A. Glavic and M. Björck
J. Appl. Cryst. 2022, 55(4), 1063-1071

BoToFit: Fitting software for neutron and x-ray reflectivity experiments

Download from GitHub

pySAred: Processing of h5 data files and data reduction

Download from GitHub

pySAsum: Visualisation and comparison of detector images at SuperADAM

Download from GitHub

Selected publications

Contact

Last modified:

FOLLOW UPPSALA UNIVERSITY ON

facebook
instagram
twitter
youtube
linkedin