Transition énergétique

Abandon de l’énergie nucléaire, développement de l’énergie solaire et éolienne, production d’énergie à partir de la biomasse, réduction de la consommation d’énergie. D’ici 2050, la Suisse doit atteindre la neutralité climatique. Un objectif ambitieux, rendu plus urgent que jamais par une situation géopolitique de plus en plus difficile. Comment faire pour mettre en place ces prochaines années un approvisionnement énergétique durable et résistant pour la Suisse? Comment les énergies renouvelables peuvent-elles être utilisées de manière optimale? Quelles sont les nouvelles technologies les plus prometteuses? Au PSI, des chercheurs s’efforcent de trouver des réponses à ces questions décisives.

Building blocks

Building blocks of an artificial kagome spin ice: Photoemission electron microscopy of arrays of ferromagnetic islands

Arrays of dipolar coupled ferromagnetic islands arranged in specific geometries provide ideal systems to
directly study frustration. We have examined with photoemission electron microscopy the magnetic configurations
in three basic building blocks of an artificial kagome spin ice consisting of one, two, and three rings.
The kagome spin ice arrangement is particularly interesting because it is highly frustrated and the three

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Super-Resolution X-ray Microscopy unveils the buried secrets of the nanoworld

A novel super-resolution X-ray microscope developed by a team of researchers from the Paul Scherrer Institut (PSI) and EPFL in Switzerland combines the high penetration power of x-rays with high spatial resolution, making it possible for the first time to shed light on the detailed interior composition of semiconductor devices and cellular structures.
The first super-resolution images from this novel microscope will be published online July 18, 2008 in the journal Science.

Nanoscale depth resolution of lattice dynamics

We employ grazing-incidence femtosecond x-ray diffraction to characterize the coherent, femtosecond laser-induced lattice motion of a bismuth crystal as a function of depth from the surface with a temporal resolution of ~200 fs. The data show direct consequences on the lattice motion from carrier diffusion and electron-hole interaction, allowing us to estimate the effective diffusion rate for the highly excited carriers and the electron-hole interaction time.

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Coherent Diffraction Imaging Using Phase Front Modifications

We introduce a coherent diffractive imaging technique that utilizes multiple exposures with modifications to the phase profile of the transmitted wave front to compensate for the missing phase information.

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X-ray dark-field imaging using a grating interferometer

A type of X-ray imaging that shows detail otherwise lost, and which is compatible with conventional radiography instrumentation is now feasible, reports a study published online in Nature Materials. This technique offers unprecedented resolution for several applications, including medical imaging, security screening and industrial non-destructive testing.