SINQ
Neutrons and synchrotron light help unlock Bronze Age techniques
Experiments conducted at the PSI have made it possible to determine how a unique Bronze Age axe was made. This was thanks to the process of neutron imaging, which can be used to generate an accurate three-dimensional image of an object’s interior. For the last decade, the PSI has been collaborating with various museums and archaeological institutions both in Switzerland and abroad. The fact that the 18th International Congress on Ancient Bronzes, which is to be held at the University of Zurich from 3 à 7 September, will also be meeting at the PSI for one day is a testament to the success of the cooperation.
Knowledge for tomorrow from "hot cells"
The manipulation and examination of irradiated and therefore radioactive objects, be they from nuclear power stations or research facilities, requires strict safety measures. Tests may only be conducted in so-called hot cells, where the radioactivity is hermetically enclosed and shielded behind concrete and lead walls up to 1 metre thick. In the hot cells of the PSI hot lab, the burnt-off fuel rods from the Swiss nuclear power stations are studied from a materials science perspective. The insights gained help nuclear power station operators to optimise the efficiency and safety of their plants. Besides this service, the hot lab is involved in several international research projects.
Fast neutrons for improved safety
Neutrons are an excellent tool for the non-destructive imaging the interior of objects. They can provide a valuable complement to the more widely used x ray radiography. For some materials that are virtually opaque or for those that cannot be distinguished by X-rays, neutrons provide the only informative dissection tool. However, neutron radiography is mainly confined to the laboratory and fixed facilities, because neutron generation relies on equipment like nuclear reactors or particle accelerators, which are costly, complex and cannot be moved. Scientists at the Laboratory for Thermohydraulics at the Paul Scherrer Institute PSI want to develop a more flexible imaging technique based on fast neutrons.
Observing Engine Oil Beneath Metal
Developmental Engineers from the firm LuK (D) wanted to see right through the metal housing of a clutch. They wanted to observe how the oil that lubricates and cools a clutch is distributed. A transparent disc becomes dirty very quickly, and X-rays merely reveal the metal. These engineers therefore turned to scientists at the Paul Scherrer Institute, who illuminated the metal with neutrons and thus made the lubricating oil visible. The results surprised everyone: only three of the eight lamellae were sufficiently lubricated.
Distribution of soot particles in particulate filters of diesel vehicles seen for the first time
Diesel motor vehicles have to be equipped with soot particulate filters, so the harmful soot and ash cannot get into the environment. Whilst these operate according to appropriate standards, up until now, the details about the distribution of soot and ash inside these filters has been unknown. Now, thanks to the special examination techniques of the Paul Scherrer Institute [PSI], the actual filter loads have been seen for the first time.
Schweiz beteiligt sich an Neutronenquelle der Zukunft
Mauro Dell’Ambrogio, Staatssekretär für Bildung und Forschung unterzeichnete heute die Absichtserklärung der Schweiz, sich an der neuen europäischen Neutronenquelle ESS (European Spallation Source) zu beteiligen. Darin bekennt sich die Schweiz zu dem Ziel, die ESS in Lund (Südschweden) zu bauen und verpflichtet sich, am Konzept mitzuarbeiten, in dem der endgültige Plan für die Anlage festgelegt wird. Kurz nach Fertigstellung des Konzepts im Frühjahr 2013 soll die Entscheidung für den Bau der ESS fallen. Die Schweizer Beiträge zur Entwicklung der Anlage werden durch das Paul Scherrer Institut, das langjährige Erfahrung in der Forschung mit Neutronen hat, sowie durch Schweizer Universitäten und die Schweizer Industrie erbracht.This news release is only available in German.
Plants create a water reserve in the soil
An international research team has now demonstrated in experiments at the Paul Scherrer Institute that the soil in the vicinity of roots contains more water that that further away. Apparently, plants create a small water reserve that helps to tide them over through short periods of drought. These results were obtained from experiments carried out with the benefit of neutron tomography.
Magnetisierte Bereiche in 3D sichtbar gemacht
Magnetisierbare Materialien sind nie völlig unmagnetisch, sondern enthalten immer magnetisierte Bereiche à die magnetischen Domänen. In einem Experiment am Helmholtz-Zentrum Berlin (HZB) konnten diese Domänen erstmals in ihrer dreidimensionalen Struktur abgebildet werden. Der Versuch beruhte auf einer Weiterentwicklung eines am Paul Scherrer Institut entstanden Verfahrens und nutzte neutronenoptische Komponenten, die am PSI hergestellt worden sind.This news release is only available in German.
What the “hairy ball theorem” tells us about flux lines in superconductors
In strong magnetic fields, type II superconductors tend to form flux lines à thin channels through which the magnetic field can pass through the superconductor. Usually, these flux lines tend to form regular patterns. Now, two physicists have shown that such a pattern must depend on the direction of the external magnetic field. These results are based on a mathematical principle known as the Hairy ball theorem.
Service to the scientific community
Neutrons, synchrotron light and muons are very useful for researchers in a variety of disciplines. Using these probes, we can determine the structure of crystals, they help us understand magnetic processes, or they can reveal the structures of biological materials. However, producing these probes is so difficult that most research groups will not have a neutron, muon or synchrotron light at their own scientific centre.