Energy transition

Shifting away from nuclear energy, expanding solar and wind power, generating energy from biomass, reducing energy consumption. Switzerland is committed to becoming climate-neutral by 2050. An ambitious goal, which has become more urgent than ever due to the increasingly challenging geopolitical situation. How can a sustainable and resilient energy supply for Switzerland be established over the coming years? What's the optimal way to use renewable energy sources? What new technologies are especially promising? At PSI, researchers are seeking answers to these crucial questions.

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.

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.

Figure 1: 22 mm aperture quadrupoles with their integrated dipole corrector coils in the assembly area of ATK before the magnetic tests.

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.

Figure 1: First Undulator in place in SwissFEL tunnel.

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.

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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.

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.

Hydrogen atoms are light and can tunnel through a barrier. Tunnelling can be quenched by substituting them with deuterium, a twice as heavy isotope of H.

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.

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.

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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.

Figure 1: Profile scan along the center of the Offset Mirror M-­‐201. The specified Profile accuracy of 3 nm PV is shown with dashed lines.

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.

 

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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.

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.

Virtual section through the middle of a seed from the Early Cretaceous exposing embryo and nutrient storage tissue. The tiny embryo shown in 3D has two rudimentary cotyledon primordia documenting the dicotyledonous nature of this extinct angiosperm. The fossil is reconstructed from synchrotron radiation X-ray tomographic microscopy measurements performed at the Tomcat beamline at the Swiss Light Source. Image: Else Marie Friis

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.

Three-dimensional rendering of two cells in their medium confined in a glass microcapillary of about 18 micron diameter. Colors indicate different organelle types with different mass densities.

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.

A sketch of the novel spin-polarized q2DEG obtained by embedding a FM EuTiO3 between LaAlO3 and SrTiO3.

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.