Am PSI widmen sich mehrere Projekte wichtigen Forschungsfragen rund um das Coronavirus Sars-CoV-2 und den daraus resultierenden Erkrankungen. Wir informieren über Aktivitäten und Vorhaben, zum Beispiel zu Untersuchungen von Lungengewebe, zur Produktion von Proteinen und Antikörpern oder über Ideen für neue Forschung zu Covid-19.
Nützliche Links
GFA delivers the SwissFEL magnets on schedule
The Paul Scherrer Institut is building an X-ray free electron laser (SwissFEL) providing a source of intense, ultra-short pulses of coherent radiation in the wavelength range of 0.1 nm to 0.7nm. For the hard X-ray beam line, the magnet section in GFA/ATK has the responsibility for the design, the procurement and the magnetic qualification of 267 electro-magnets of 22 different types. Several design studies were performed in an attempt to meet the required magnet specifications while optimizing construction and operation cost.
Biophysical effects of UV radiation on biological samples
The biological influence of radiation on living matter has been studied for years; however, several questions about the detailed mechanism of radiation damage formation remain largely unanswered. Among all biomolecules exposed to radiation, DNA plays an important role because any damage to its molecular structure can affect the whole cell and may lead to chromosomal rearrangements resulting in genomic instability or cell death.
Schwerfälliger Stromfluss könnte Weg zu energiesparenden Computern weisen
Computer und andere elektronische Geräte haben heute einen beträchtlichen Anteil am weltweiten Energieverbrauch. Mit den heute genutzten Technologien lässt sich dieser Verbrauch aber kaum senken, sodass die Chips in den energiesparenden Geräten der Zukunft aus neuartigen Materialien bestehen werden. Neueste Forschungsergebnisse aus dem Paul Scherrer Institut PSI geben Hinweise darauf, wie man zu solchen Materialien kommen könnte.
Transport of first "completed" Undulator into the SwissFEL Tunnel
On the 25th of January, the first "completed" undulator has been transported to its final position in the SwissFEL tunnel. The 1064 permanent magnets of this undulator where shimmed to the sub-micrometer level and the magnetic profile has been carefully measured for the full gap range. Twelve of such undulators will be installed until October 2016!
Small-Angle Neutron Scattering Study of Interplay of Attractive and Repulsive Interactions in Nanoparticle-Polymer System
The phase behavior of nanoparticle (silica)−polymer (polyethylene glycol) system without and with an electrolyte (NaCl) has been studied. It is observed that nanoparticle−polymer system behaves very differently in the presence of electrolyte. In the absence of electrolyte, the nanoparticle−polymer system remains in one-phase even at very high polymer concentrations.
Georgian Order of Honor for Zurab Guguchia
Thomas Prokscha from Laboratory for the Muon Spin Spectroscopy LMU and Head of the LEM Group was invited to serve an additional year as a member of the INTC Committee (ISOLDE and Neutron Time-of-Flight Experiments Committee) at CERN.
The INTC evaluates proposals for experiments on the ISOLDE facility. In addition it reviews the experiments proposed for the neutron time-of-flight facility.
Wiederwahl der Direktoren von PSI und WSL
Der Bundesrat hat am 20. Januar 2016 auf Antrag des ETH-Rats den Direktor des Paul Scherrer Instituts PSI, Joël Mesot, und den Direktor der Eidgenössischen Forschungsanstalt für Wald, Schnee und Landschaft WSL, Konrad Steffen, für weitere vier Jahre wiedergewählt. Die dritte Amtszeit von Joël Mesot beginnt am 1. August 2016, die zweite Amtszeit von Konrad Steffen am 1. Juli 2016.
Mechanically Enhanced Liquid Interfaces at Human Body Temperature Using Thermosensitive Methylated Nanocrystalline Cellulose
The mechanical performance of materials at oil/water interfaces after consumption is a key factor affecting hydrophobic drug release. In this study, we methylated the surface of nanocrystalline cellulose (NCC) by mercerization and dimethyl sulfate exposure to produce thermosensitive biopolymers. These methylated NCC (metNCC) were used to investigate interfacial thermogelation at air/water and medium-chain triglyceride (MCT)/water interfaces at body temperature.
Controlling tunnelling in methane loss from acetone ions by deuteration
If a ball is rolled up a hill with less kinetic energy than the potential energy at the top, it will return eventually, and stays bound in the valley. Tunnelling is a distinctly quantum mechanical phenomenon, in which such balls can magically cross the hill, and appear in the neighbouring valley, as if going through a tunnel. In order for this to happen with a non-negligible probability, the ball has to be small and the barrier, i.e. the hill, sharp.
Gezielt gegen Krebs
Es gibt Tumore, bei denen scheinbar gar nichts hilft: weder Chemotherapie noch Bestrahlung von aussen oder eine Operation. Oft haben sie schon Tochtergeschwülste gebildet und lassen sich mit herkömmlichen Methoden nicht mehr zerstören. Dann bleibt als einziger Ausweg die Bestrahlung von innen, mit radioaktiven Wirkstoffen zielgerichtet und direkt am Ort des Geschehens. Um das zu ermöglichen, forschen 20 Spezialisten am Zentrum für radiopharmazeutische Wissenschaften am Paul Scherrer Institut PSI, einer gemeinsamen Einrichtung von PSI, ETH Zürich und dem Universitätsspital Zürich.
Self-Diffusion in Amorphous Silicon
The present Letter reports on self-diffusion in amorphous silicon. Experiments were done on 29Si/natSi heterostructures using neutron reflectometry and secondary ion mass spectrometry. The diffusivities follow the Arrhenius law in the temperature range between 550 and 700°C with an activation energy of (4.4 ± 0.3) eV.
Neutronen zeigen Verteilung von Flussschlauch-Inseln
Normalerweise verdrängen Supraleiter angelegte Magnetfelder. Im Inneren von Typ-II-Supraleitern bilden sich aber dünne Kanäle, sogenannte Flussschläuche, durch die das Magnetfeld geleitet wird, während das restliche Material feldfrei und supraleitend bleibt. In dem Metall Niob bündeln sich die Flussschläuche zu kleinen Inseln zusammen und bilden dabei komplexe Muster, welche in ähnlicher Form zahlreich in der Natur anzutreffen sind. Forschende des PSI und der TU München haben als erste Neutronenexperimente zur Untersuchung dieser Strukturen in dem Metall Niob durchgeführt und dabei die Verteilung der Inseln im Detail sichtbar gemacht.
First ultraprecise mirror for SwissFEL arrived at PSI
Mirrors are key elements to distribute and shape the Xray beam generated by the undulators of the SwissFEL facility. They are essential tools to guide and focus the light according to the specific users requirements and should do this without noticeable effects on the beam quality. A quantitative measure is the quality of the beam wavefront. The wavefront must be conserved by the optical elements in the SwissFEL beamlines within a fraction of the wavelength which can be as short as one Angstrom in the case of Aramis. There are only few companies in the world, who are able to fabricated such ultraprecise mirrors.
In-situ visualization of stress-dependent bulk magnetic domain formation by neutron grating interferometry
The performance and degree of efficiency of industrial transformers are directly influenced by the magnetic properties of high-permeability steel laminations (HPSLs). Industrial transformer cores are built of stacks of single HPSLs. While the insulating coating on each HPSL reduces eddy-current losses in the transformer core, the coating also induces favorable inter-granular tensile stresses that significantly influence the underlying magnetic domain structure.
First ultraprecise mirror for SwissFEL arrived at PSI
Mirrors are key elements to distribute and shape the Xray beam generated by the undulators of the SwissFEL facility. They are essential tools to guide and focus the light according to the specific users requirements and should do this without noticeable effects on the beam quality. A quantitative measure is the quality of the beam wavefront.
Endlagersuche: Viele 100'000 Jahre sicher im Ton
Obwohl die Schweiz aus der Kernenergie aussteigt, muss sie eine Lösung für das in den Kernkraftwerken, aber auch in Medizin, Industrie und Forschung entstandene, radioaktive Material finden. Daher stellt sie sich einer aussergewöhnlichen, verantwortungsvollen Aufgabe: Sie sucht einen Ort, an dem sie ihre radioaktiven Abfälle mehrere hunderttausend Jahre lang sicher lagern kann. So lange, bis sie von selbst die Radioaktivität natürlicher Gesteine erreicht haben.
Rate of Molecular Transfer of Allyl Alcohol across an AOT Surfactant Layer Using Muon Spin Spectroscopy
The transfer rate of a probe molecule across the interfacial layer of a water-in-oil (w/o) microemulsion was investigated using a combination of transverse field muon spin rotation (TF-μSR), avoided level crossing muon spin resonance (ALC-μSR), and Monte Carlo simulations. Reverse micro-emulsions consist of nanometer-sized water droplets dispersed in an apolar solvent separated by a surfactant monolayer.
Determining the structures of nanocrystalline pharmaceuticals by electron diffraction
A new type of detector developed by Dr. van Genderen enables the structure determination of pharmaceutical compounds with electron diffraction at room temperature. The group concentrate on expanding this new technique to macromolecular compounds.
Ab in den Strahlkanal
Seit Herbst 2015 füllt sich der SwissFEL-Strahlkanal mit den Maschinenkomponenten für die neue PSI-Grossforschungsanlage. Stück für Stück werden die vormontierten Komponenten an ihren endgültigen Standort gebracht.
Mass density distribution of intact cell ultrastructure
The determination of the mass density of cellular compartments is one of the many analytical tools that biologists need to unravel the extremely complex structure of biological systems. Cryo X-ray nanotomography reveals absolute mass density maps of frozen hydrated cells in three dimensions.
Preserved Embryos Illustrate Seed Dormancy in Early Angiosperms
The discovery of exceptionally well-preserved, tiny fossil seeds dating back to the Early Cretaceous corroborates that flowering plants were small opportunistic colonizers at that time, according to a new Yale-led study.
Die Vermessung der Gleichzeitigkeit
Was macht ein Physiker, wenn sein Experiment eine hochgenaue Zeiterfassung benötigt? So genau, dass bestehende Elektronik kaum weiterhilft? Ein Forscher des Paul Scherrer Instituts PSI hat sich kurzerhand entschlossen, selbst eine Lösung zu entwickeln. Die heisst DRS4 und ist ein hochpräziser Elektronikchip, der die Physik unseres gesamten Universums entschlüsseln könnte. Nebenbei hilft der Chip schon heute Ärzten, Hirntumore genauestens zu lokalisieren.
Tunable spin polarization and superconductivity in engineered oxide interfaces
A new kind of 2DEG is found by inserting two atomic layers of the antiferromagnetic and insulating compound EuTiO3 between LaAlO3 and SrTiO3. The 2DEG is found to exhibit besides a superconducting ground state, a strong spin-polarization. The magnetism of Eu and Ti was studied by XMCD at the X-Treme beamline in SLS.
Kohlendioxid: Das Klimaproblem im Untergrund entsorgen?
Allen Warnungen vor den Folgen des Klimawandels zum Trotz und unbeeindruckt von politischen Absichtserklärungen: Die weltweiten Kohlendioxidemissionen steigen und steigen. Hauptverantwortlich dafür sind Kohle- und Gaskraftwerke, die den zunehmenden Strombedarf decken. Könnte man deren Kohlendioxidemissionen dauerhaft im Boden speichern, anstatt damit Atmosphäre und Klima zu belasten? Und wäre das auch für die Schweiz interessant? Diese Fragen beleuchtet der neueste Energie-Spiegel des PSI.
First EIGER X 16M in operation at the Swiss Light Source
The macromolecular crystallography beamline X06SA at the Swiss Light Source, a synchrotron operated by Paul Scherrer Institute, is the first one in the world to upgrade its detector to an EIGER X 16M.
The flip-over effect in pulsed laser deposition: Is it relevant at high background gas pressures?
In pulsed laser deposition the use of a rectangular or elliptical beam spot with a non 1:1 aspect ratio leads to the so called flip-over effect. Here, the longest dimension of the laser spot results in the shortest direction of plasma plume expansion.
Controlling tunnelling in methane loss from acetone ions by deuteration
If a ball is rolled up a hill with less kinetic energy than the potential energy at the top, it will return eventually, and stays bound in the valley. Tunnelling is a distinctly quantum mechanical phenomenon, in which such balls can magically cross the hill, and appear in the neighbouring valley, as if going through a tunnel. In order for this to happen with a non-negligible probability, the ball has to be small and the barrier, i.e. the hill, sharp.
3-D-Nanostruktur eines Knochens sichtbar gemacht
Knochen bestehen aus winzigen Fasern, die etwa tausend Mal feiner sind als ein menschliches Haar. Mit einer neuartigen computerbasierten Auswertungsmethode konnten Forschende des Paul Scherrer Instituts PSI zum ersten Mal die Anordnung dieser Nanostrukturen innerhalb eines gesamten Knochenstücks sichtbar machen.
Nanostructure surveys of macroscopic specimens by small-angle scattering tensor tomography
The mechanical properties of many materials are based on the macroscopic arrangement and orientation of their nanostructure. This nanostructure can be ordered over a range of length scales. In biology, the principle of hierarchical ordering is often used to maximize functionality, such as strength and robustness of the material, while minimizing weight and energy cost.
Aluminium X-ray absorption near-edge spectroscopy analysis of discoloured ultramarine blue in 20th century oil paintings
A specific case of synthetic ultramarine degradation was observed in three oil paintings from the early 20th century. Pigment particleswere found to have been discoloured, resulting in intricate patterns ofwhite lines, approximately 10 to 30 microns wide, criss-crossing the paint surface. Colour in ultramarine pigments comes from the encapsulated sulphur radical anions, chromophores, inside the cage framework built from SiO4 4 − and AlO4 5 −