At PSI, several projects are dedicated to important research questions concerning the Sars-CoV-2 coronavirus and the resulting diseases. We provide information on activities and projects, for example on investigations of lung tissue, on the production of proteins and antibodies or on ideas for new research on Covid-19.
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A new bio-robot
With a new method for modifying antibodies, Philipp Spycher, winner of a Founder Fellowship at the Paul Scherrer Institute PSI, wants to develop drugs that are more stable and, thus, have fewer side-effects.
Spin Resonance and Magnetic Order in an Unconventional Superconductor
Unconventional superconductivity in many materials is believed to be mediated by magnetic fluctuations. It is an open question how magnetic order can emerge from a superconducting condensate and how it competes with the magnetic spin resonance in unconventional superconductors. Here we study a model d-wave superconductor that develops spin-density wave order, and find that the spin resonance is unaffected by the onset of static magnetic order.
Special interview with Prof. Thomas Lippert and Prof. Tatsumi Ishihara
Special interview with Prof. Thomas Lippert (PSI and Principle Investigator at I2CNER, Kyushu University) and Prof. Tatsumi Ishihara (Associate Director I2CNER, Kyushu University) on Current and Future Energy Research and Development in Europe: Perspectives from Switzerland, Germany and Japan. The interview is being published in the August 2017 issue of the Energy Outlook of the International Institut for Carbon-Neutral Energy Research, I2CNER.
Dorothea vom Bruch successfully defends her Ph.D. thesis on the Mu3e filter farm and MuPix timing behaviour
Dorothea vom Bruch developed and implemented the algorithms for the Mu3e filter farm, showing that just 12 PCs with powerful GPUs are sufficient to reduce over 10 Gbyte/s of data to manageable levels. She also performed detailed studies of the position dependent timing behaviour of the MuPix7 HV-MAPS prototype. She has now successfully defended her thesis in Heidelberg.
Stress test passed
With a technology developed at the Paul Scherrer Institute PSI, around 60 percent more biogas can be produced from bio-waste than with conventional methods. But can it stand the test in practice as well? A 1,000-hour test at the Werdhölzli biowaste digestion and wastewater treatment plant in Zurich was able to answer this question with a clear yes. It was carried out in cooperation with the Zurich-based energy provider Energie 360°. The analysis of the stress test is now available.
Emergent dynamic chirality in a thermally driven artificial spin ratchet
Modern nanofabrication techniques have opened the possibility to create novel functional materials, whose properties transcend those of their constituent elements. In particular, tuning the magnetostatic interactions in geometrically frustrated arrangements of nanoelements called artificial spin ice can lead to specific collective behaviour, including emergent magnetic monopoles, charge screening and transport, as well as magnonic response.
Magnetic structures take a new turn
The unexpected finding that in an ‘artificial spin ice’ magnetostatic energy can be transformed into directed rotation of magnetization provides fresh insights into such nano-patterned magnetic structures — and might enable novel applications in nanoscale devices.
The importance of knowing your stripes
A collaboration between three NUM laboratories has found that magnetic ‘stripe order’ in high-temperature superconductors not only co-exists with superconducting order, but might very well be intimately connected with it.
First light in SwissFEL Experimental Station Bernina
Friday, October 20th, 2017, we brought the first light (wavelength 1.2 nm) into the experimental hutch of Bernina. The beam passed the Alvra endstation, went through the diagnostic devices and hit the diagnostic screen in front of the refocussing KB-system of Bernina. The upper picture shows the pink beam on the last diagnostic screen of the beamline. The lower left at the entrance of Bernina-hutch, 133 m downstream of the undulator. The lower right picture shows the beam centered in the alignment iris in front of the KB-system.
MultiFLEXX - The new multi-analyzer at the cold triple-axis spectrometer FLEXX
The first experimental characterization of a multiple energy analysis wide angle backend for a cold triple-axis spectrometer is reported. The multi-analyzer module MultiFLEXX employs 155 detection channels which simultaneously probe an extensive range in wavevector and energy transfer. Successful mapping of magnetic excitations in MnF2 and Ho demonstrate order of magnitude gains in data collection efficiency using this novel type backend.
First light in SwissFEL Experimental Station Bernina
Friday, October 20th, 2017, we brought the first light (wavelength 1.2 nm) into the experimental hutch of Bernina.
The beam passed the Alvra endstation, went through the diagnostic devices and hit the diagnostic screen in front of the refocussing KB-system of Bernina.
The upper picture shows the pink beam on the last diagnostic screen of the beamline.
The lower left at the entrance of Bernina-hutch, 133 m downstream of the undulator.
Signatures of the topological s+- superconducting order parameter in the type-II Weyl semimetal Td-MoTe2
In its orthorhombic Td polymorph, MoTe2 is a type-II Weyl semimetal, where the Weyl fermions emerge at the boundary between electron and hole pockets. Non-saturating magnetoresistance and superconductivity were also observed in Td-MoTe2. Understanding the superconductivity in Td-MoTe2, which was proposed to be topologically non-trivial, is of eminent interest.
Making the world go round - a look into the structure of a prominent heterogeneous catalyst
Fluid catalytic cracking catalysts, which are composite particles of hierarchical porosity, were examined using ptychographic X-ray tomography. These particles are essential to the conversion of crude oil into gasoline. Examination of catalysts at decreasing levels of catalytic conversion efficacy allowed the detection of possible deactivation causes.
Time- and spatially-resolved magnetization dynamics driven by spin-orbit torques
Current-induced spin-orbit torques hold a great potential for manipulation of magnetization at ultrafast timescales. Researchers at ETH Zürich have demonstrated, using time-resolved STXM imaging at the Swiss Light Source, the influence of spin-orbit torques on the switching behaviour of Pt/Co/AlOx nanostructured elements.
Frustratingly disordered
A study of how disorder affects a ‘frustrated’ magnet reveals a surprising robustness of the underlying quantum many-body state, and provides evidence for emerging quantum phenomena induced by disorder.
Coulomb spin liquid in anion-disordered pyrochlore Tb2Hf2O7
The charge ordered structure of ions and vacancies characterizing rare-earth pyrochlore oxides serves as a model for the study of geometrically frustrated magnetism. The organization of magnetic ions into networks of corner-sharing tetrahedra gives rise to highly correlated magnetic phases with strong fluctuations, including spin liquids and spin ices. It is an open question how these ground states governed by local rules are affected by disorder.
Highly Crystalline C8-BTBT Thin-Film Transistors by Lateral Homo-Epitaxial Growth on Printed Templates
Highly crystalline thin films of organic semiconductors offer great potential for high-performance, low-cost flexible electronics. Researchers at IMEC Belgium have developed a new double-step thin film fabrication process that offers higher performance devices. Soft X-ray spectro-microscopy at the Swiss Light Source was used to prove that the increased performance comes from larger areas of material sharing the same molecular orientation.
From golden emperor to filled Buddha
Ancient metal objects are illuminated by neutrons at the Paul Scherrer Institute PSI. This enables researchers to discover what is hidden inside them, how they were made and how they can be preserved.
Johannes Ihli and co-researchers made it into Nature Communications
Nature Communications will be publishing the paper of Johannes Ihli et al., "A three-dimensional view of structural changes caused by deactivation of fluid catalytic cracking catalysts", in issue 8, article number 809. The paper has already gone online on October 9, 2017.
Tracking the Chemical Transformations at a Zeolite Brønsted Acid Site with Al K-edge XANES
Al T-sites are of crucial importance for the function of zeolite catalysts. These T-sites, which serve as Brønsted acid reaction centers, interact strongly with water. The location of these T-sites and their chemical state in the presence of water were elucidated using x-ray absorption spectroscopy (XAS) at the PHOENIX beamline at the Swiss Light Source of the PSI.
Highlighting the significance of structural analysis of biomolecules
The Nobel Prize in Chemistry 2017 has been awarded to Jacques Dubochet of Switzerland, U.S.-based German scientist Joachim Frank, and Richard Henderson of the United Kingdom for the development of structural analysis of single biological molecules by means of cryo-electron microscopy. The awarding of the prize underscores the fundamental significance of structural analysis of biomolecules for modern biology – a research area where the Paul Scherrer Institute PSI plays a leading role in Switzerland.
First MuPix8 beam test at DESY
We are testing our new large sensor chip, the MuPix8, in the electron beam at DESY, Hamburg. One of the high resolution EUDET telescopes serves as a reference for efficiency and resolution measurements.
Pt nanoparticles: The key to improved stress corrosion cracking mitigation in boiling water reactors
The formation and growth of cracks by stress corrosion cracking (SCC)in reactor internals and recirculation pipes due to the highly oxidising environment is a serious issue in boiling water reactors. At first, SCC mitigation was attempted by injecting H2 into the feed water, where the injected H2 recombines with the H2O2 and O2 to water and reduces the electrochemical corrosion potential, and consequently the SCC susceptibility. Several disadvantages of the injection of high amounts of H2, have led to the development of noble metal additions to the reactor feed water. With injection of a much smaller amount of H2, the noble metal particles of a few nanometres in size, formed in-situ, work as catalysts for the efficient reduction of the oxidizing species formed by radiolysis, and thus lower the ECP and SCC susceptibility.
Best publication
A team of GFA and CPT physicists has worked out a novel achromatic beam optics concept for a proton therapy gantry. The article on the concept in the journal Zeitschrift für Medizinische Physik has been awarded a prize for the best publication in 2016. The jury states: „The paper of Alexander Gerbershagen et al. entitled „A novel beam optics concept in a particle therapy gantry utilizing the advantages of superconducting magnets” describes a new concept of a first order design of the beam optics of a superconducting proton therapy gantry beam. The jury was impressed by the well-structured experimental work with clear improvement of large momentum acceptance in the gantry which opens the possibility of implementation new and faster dose application techniques in proton therapy.”
Collaboration meeting in Mainz and new collaborators
In a two day meeting in Mainz we had the pleasure of welcoming four new institutes, namely the universities of Liverpool, Oxford and Bristol as well as University College London to the collaboration. We also discussed progress on all subdetectors and a variety of integration issues.
Atmosphere in X-ray light
PSI researchers have developed an experimental chamber in which they can recreate atmospheric processes and probe them with unprecedented precision, using X-ray light from the Swiss Light Source SLS. In the initial experiments, they have studied the production of bromine, which plays an essential role in the decomposition of ozone in the lower layers of the atmosphere. In the future, the new experiment chamber will also be available for use by researchers from other scientific fields.
Light from the particle accelerator helps to understand ozone decomposition
PSI researchers have developed an experimental chamber in which they can recreate atmospheric processes and probe them with unprecedented precision, using X-ray light from the Swiss Light Source SLS. In the initial experiments, they have studied the production of bromine, which plays an essential role in the decomposition of ozone in the lower layers of the atmosphere. In the future, the new experiment chamber will also be available for use by researchers from other scientific fields.
Dr. Konstantins Jefimovs wins the 2nd poster prize
Dr. Konstantins Jefimovs from the TOMCAT team at SLS was awarded with the 2nd poster prize at the 4th XNPIG Conference (X-ray and Neutron Phase Contrast Imaging with Gratings) held in Zürich, September 12th-15th. He presented latest achievements on gratings fabrication under the title: “Large area small pitch gratings for X-ray interferometry by Displacement Talbot Lithography”.
Dr. Matias Kagias receives the William H. F. Talbot Award 2017
Dr. Matias Kagias from the TOMCAT team at SLS is the recipient of the William H. F. Talbot Award 2017, as announced recently at the 4th XNPIG Conference (X-ray and Neutron Phase Contrast Imaging with Gratings) held in Zürich in September 12th-15th. The award is given to young PhD students for their outstanding contributions in the field of X-ray and Neutron Phase contrast imaging. This award has been introduced this year and Dr. Kagias is the first recipient ever.
Coexistence of Physisorbed and Solvated HCl at Warm Ice Surfaces
The interfacial ionization of strong acids is an essential factor of multiphase and heterogeneous chemistry in environmental science, cryospheric science, catalysis research and material science. Using Near Ambient Pressure X-ray Photoelectron (NAPP) spectroscopy, we directly detected a low surface coverage of adsorbed HCl at 253 K in both molecular and dissociated states and interpret the results as physisorbed molecular HCl at the outermost ice surface and dissociation occurring upon solvation deeper in the interfacial region. This study gives clear evidence for nonuniformity across the air−ice interface and questions the use of acid−base concepts in interfacial processes.