Textbook on XAS and XES
During the last two decades, remarkable and often spectacular progress has been made in the methodological and instrumental aspects of x–ray absorption and emission spectroscopy. This progress includes considerable technological improvements in the design and production of detectors especially with the development and expansion of large-scale synchrotron reactors All this has resulted in improved analytical performance and new applications, as well as in the perspective of a dramatic enhancement in the potential of x–ray based analysis techniques for the near future.
Transport von aufgelösten Plutoniumlager des Bundes in die USA ist erfolgt
Im Januar und Februar 2016 wurden unter strengen Sicherheitsvorkehrungen rund 20kg Plutonium im Eigentum des Bundes in die USA transportiert. Es handelt sich dabei um Material, das seit den 1960er Jahren auf dem Areal des heutigen Paul Scherrer Instituts (PSI) gelagert worden war. Das Plutonium stammte aus wiederaufbereiteten Brennstäben des von 1960 bis 1977 betriebenen Forschungsreaktors Diorit. Der Bundesrat beschloss 2014 im Rahmen des Nuclear Security Summit-Prozesses, das Plutoniumlager aufzulösen und damit zur weltweiten Sicherung von Nuklearmaterial beizutragen.This news release is only available in French and German.
In situ stress observation in oxide films and how tensile stress influences oxygen ion conduction
Many properties of materials can be changed by varying the interatomic distances in the crystal lattice by applying stress. Ideal model systems for investigations are heteroepitaxial thin films where lattice distortions can be induced by the crystallographic mismatch with the substrate. Here we describe an in situ simultaneous diagnostic of growth mode and stress during pulsed laser deposition of oxide thin films.
Cooperation with nature
With SwissFEL, a new landscape takes shapeBarely completed, the building housing the X-ray free-electron laser SwissFEL has disappeared again beneath a mound of earth. Since then, planting and landscaping have been under way on and around this major research facility of the Paul Scherrer Institute PSI. Its special location, in a forest, demands that SwissFEL be integrated in an environmentally appropriate way. So the facility is, from the outside, nearly invisible. And rare animals and plants have gained new living space.
Decommissioning of the research reactor Proteus
Start of the public examination period for decommissioning of the nuclear facility Proteus at the Paul Scherrer Institute PSIThe nuclear research facility Proteus is a so-called zero-power reactor. In service, the thermal output of the reactor was limited to a maximum of 1 kW. That means this is an experimental reactor that was run at a power level so low that it did not require cooling. Proteus went into service in 1968. The PSI would like to decommission the facility. The decommissioning project is now being publicly announced in the legally prescribed, official publications.
Dramatic pressure-driven enhancement of bulk skyrmion stability
The recent discovery of magnetic skyrmion lattices initiated a surge of interest in the scientic community. Several novel phenomena have been shown to emerge from the interaction of conducting electrons with the skyrmion lattice, such as a topological Hall-effect and a spin-transfer torque at ultra-low current densities.
Developing a new drug against thyroid cancer
Researchers at the Paul Scherrer Institute PSI have developed a drug to trace and treat a particularly malignant strain of thyroid cancer more effectively. One advantage of the new drug is that it can be used to treat a strain of thyroid cancer where the established treatment is ineffective. The researchers at PSI have developed the new drug to such an extent that an initial study conducted on cancer patients at the University Hospital Basel can now get underway.
A micrometer-sized model of the Matterhorn
Researchers at the Paul Scherrer Institute have produced large numbers of detailed models of the Matterhorn, each one less than a tenth of a millimetre in size. With this, they demonstrated how 3-D objects so delicate could be mass-produced. Materials whose surface is covered with a pattern of such tiny 3-D structures often have special properties, which could for example help to reduce the wear and tear of machine parts.
Installation progress of the SwissFEL Linac
The installation of the linear accelerator (Linac) progresses very well. This week, the last girder of the so-called “Linac 1” was installed in the SwissFEL tunnel. The entire C-band accelerator consists out of Linac 1, Linac 2, and Linac 3, and a total amount of 104 accelerating structures. Meanwhile, 38 accelerating structures are installed in the SwissFEL tunnel. The assembly work on the remaining Linac modules will take place until end of September of this year. By then it is planned to finish the installation of all Linac modules in the SwissFEL tunnel.
The hotlab research facility
Start of the public examination period for renewed authorization to operate the research facility hotlab at the Paul Scherrer Institute PSIThe hotlab at the Paul Scherrer Institute PSI is a facility, unique in Switzerland, where researchers study highly radioactive materials in specially shielded chambers called hot cells. It serves the needs of applied materials research on highly radioactive samples from core structural components and fuel rods from nuclear power plants, research reactors, and the PSI radiation facilities. Through its operation of the hotlab, the Paul Scherrer Institute also contributes to the safety of the nuclear power plants in Switzerland. Around thirty staff members attend to the hotlab's safety technology and analysis infrastructure.
Proton Accelerator Operation Statistics 2015
For the first time in the history of the High Intensity Proton Accelerator the availability of the facility reached an outstanding value of 95% in 2015 with a record value of 99.3% in week 44. In comparison to the two previous years this corresponds to a reduction of the downtime by 50%. The user operation in 2015 was started as scheduled and already in the first week the machine was available 97% of the scheduled beam time. In addition to the smooth operation of the facility, high intensity beam experiments could regularly be performed with currents of up to 2.4 mA. nu
Coexistence of low-moment magnetism and superconductivity in tetragonal FeS and suppression of Tc under pressure
The family of iron-based superconductors has recently acquired a new member material, FeS. Theoretically, this compound has been shown to have electronic structure similar to that of the superconducting FeSe. However, contradictory ground states have been predicted for FeS. In this work, a collaboration of authors from Switzerland and Germany use muon spin rotation and relaxation to show that weak-moment magnetism microscopically coexists with bulk superconductivity.
Probing what sets the heart racing
New insights into the workings of important drug receptorsMany medical drugs operate on specific receptors located in the outer walls of our body’s cells. One of these is called the beta-1 adrenergic receptor. Among other things, it is responsible for palpitation, the racing pulse that we feel with stage fright or infatuation. How it transmits signals to the cellular interior can now be revealed in detail. These findings could help scientists better understand many drugs' mode of action.
Porträt Jenna Poonoosamy: Die Vermesserin der Gesteinsporen
Drei Jahre in Folge hat Jenna Poonoosamy den Preis für die beste Präsentation am Doktorandentag im Bereich Nukleare Energie und Sicherheit (NES) am Paul Scherrer Institut PSI erhalten. Poonoosamy stammt ursprünglich von der Insel Mauritius im Indischen Ozean. Schon in der Schule interessierte sie sich vor allem für Chemie. «Die meisten meiner Freunde wollten in die Wirtschaft», erzählt sie. «Mich dagegen haben die Naturwissenschaften fasziniert.» Und so zog sie nach der Schule zum Chemie-Studium nach Paris. Und kam später für ihre Doktorarbeit ans PSI.
At the interface
Interview with Stefan Janssen, Head of the User Office
Stefan Janssen is Head of the User Office at Paul Scherrer Institute PSI. In an interview, he explains why the PSI’s large research facilities are popular with researchers coming from other institutions, how he handles the many applications and how he supports users who come here to conduct experiments.
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.
Slowed down current could point the way to energy-saving computers
Computers and other electronic devices account for a substantial portion of worldwide energy use. With today’s technologies, it is not possible to reduce this energy consumption significantly any further; chips in the energy-saving electronics of the future will hence have to be made from novel materials. Researchers at the Paul Scherrer Institute PSI have now found important clues in the search for such materials.
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.
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.
Reappointment of the Directors of PSI and WSL
On application of the ETH Board, the Federal Council reappointed the Director of the Paul Scherrer Institute PSI, Joël Mesot, and the Director of the Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Konrad Steffen, for another four years on 20 January 2016. Joël Mesot’s third term of office will start on 1 August 2016, Konrad Steffen’s second term of office on 1 July 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.
Targeting cancer
There are tumours where nothing seems to help: not chemotherapy, not external radiation therapy, not an operation. Often, they have already metastasised and can no longer be destroyed using conventional methods. The only option left here is internal radiotherapy with targeted radioactive drugs that strike directly at the heart of the disease. In order to make this possible, twenty specialists have been conducting research at the Centre for Radiopharmaceutical Sciences at the Paul Scherrer Institute PSI, a joint facility of PSI, ETH Zurich and the University Hospital Zurich.
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.
Neutrons reveal distribution of flux-tube islands
Usually, superconductors expel magnetic fields. In type II superconductors, however, thin channels – so-called flux tubes – are formed. The magnetic field is guided through these tubes while the rest of the material remains field-free and superconducting. In the metal niobium, the flux tubes bunch together into small islands that create complex patterns similar to those found in other fields of nature. A team of researchers from PSI and TU München were the first to conduct neutron experiments to study these patterns in niobium and determine the distribution of the islands in detail.
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.