INSIDER-Newsletter // Issue 04, July 2022
HZDR comes out on top in imaging contest
Scientific images are of great importance for research, but they can also be artistically and aesthetically valuable. The "Best Scientific Image Contest" has set itself the task of finding images that excel in both areas. In this year's competition, more than one hundred images were submitted by scientists all over the Helmholtz Association. Now, Helmholtz Imaging has announced the results: With a total of sven images in the Top 20, the most finalists among all research centers come from HZDR. Scientists Dr. Michael Bussmann (Jury Award 2nd Place), René Booysen (Jury Award 3rd Place) and Anna Vanderbruggen (Public Choice Award 2nd Place) received awards. Here, the finalists present their contributions.
From July 10 to 21, the Helmholtz Imaging Roadshow featuring the 20 best images of the competition will be on display at the Center for Advanced Systems Understanding (CASUS) in Görlitz (Untermarkt 19). Further information
Hydrogen bubble against Marangoni convection | Aleksandr Bashkatov (Institute of Fluid Dynamics)
Hydrogen bubble against Marangoni convection
Source: Bashkatov, Aleksandr
On the image, visualization of thermocapillary driven convection also known as Marangoni convection around the hydrogen gas bubble is presented during water electrolysis. The recording was performed using a Particles Tracking Velocimetry system consisting of a high-speed camera connected to the microscope and a high-intensity laser. The visualization was carried out at 1.000 frames per second, using 5-micrometer polystyrene fluorescent particles seeded into the flow and illuminated by the laser. The light emitted by the fluorescent particles, representing their trajectories over time, was first recorded by the camera and finally averaged over a time interval of 50 milliseconds. For a successful transition towards a net-zero-emissions industry, it is crucial to replace fossil fuels such as natural gas by renewable energy sources. One promising technology is water electrolysis using solar- or wind-derived electricity to produce high-purity hydrogen gas.
Nepheline Crystal with Pectolite | Dr. Robert Möckel (Helmholtz Institute Freiberg for Resource Technology)
Nepheline Crystal with Pectolite
Source: Dr. Möckel, Robert
The micrograph was taken using a cathodoluminescence (CL) microscope, where an electron beam induces fluorescence radiation, partly in the visible range. The picture shows an almost quadratic appearing nepheline crystal (blue), surrounded by pectolite (yellow). The sample derives from the llimaussaq intrusive complex in Greenland, a part of which is famous for its rare-earth element (REE) deposit. The shown minerals do not contain larger amounts or REE, though. The picture was taken using an Olympus microscope and a lumic HC7-LM cathodoluminescence stage, image width approximately 3 millimeters. Due to the colors we could also name it the Ukrainian Silicate.
Laser Wakefield Accelerator for Electrons | Dr. Michael Bussmann (Center for Advanced Systems Understanding) | Jury Award 2nd Place
Laser Wakefield Accelerator with Electrons
Source: Dr. Bussmann, Michael
This image depicts a laser wakefield accelerator for electrons. This technology allows to shrink accelerators from kilometers size to a few centimeters, producing beams of unique quality. These unique beams are potential drivers of highly compact X-ray and gamma ray light sources. These compact light sources are envisioned to complement existing large-scale light sources and to democratize access to such sources due to their reduced cost and space requirements compared to conventional light sources. Experiments conducted at HZDR routinely produce ultrashort, nanocoulomb class electron bunches of several hundred megaelectronvolt energy. Simulations of these special accelerators require exascale compute capabilities. They produce several hundred Terabyte per second of data (at 20 time steps and more per second). On the largest supercomputers in the world this speed up for the first time allows to produce real time interactive movies of these simulations using strongly-coupled in-situ visualization.
A bite of hydrogen ice | Stefan Assenbaum (Institute of Radiation Physics)
A bite of hydrogen ice
Source: Assenbaum, Stefan
The image shows a continuous jet of cryogenic solid hydrogen that is used as a target for laser-driven proton acceleration at the DRACO laser facility at HZDR. A part of the cylindrical target with a diameter of 4.4 micrometer is evaporated after irradiation by a 14-picosecond long laser pulse. This laser pulse is incident from the left and is too weak to damage the target front directly. However, due to focusing within the dielectric hydrogen cylinder, the local intensity at the target rear side surpasses the dielectric breakdown threshold, causing local ionization and evaporation of material. Studying this laser-target interaction around the damage threshold intensity is crucial for high power laser physics, as it defines the start of plasma formation during the rising flank of a high-power laser.
Lithium ion battery recycling | Anna Vanderbruggen (Helmholtz Institute Freiberg for Resource Technology) | Public Choice Award 2nd Place
Lithium ion battery recycling
Source: Vanderbruggen, Anna
These particles come from the fine fraction of lithium ion battery recycling. I used a scanning electron microscope SEM images. In reality, everything looks black, but I used the superposition of the backscattered electron (BSE) image and secondary electron (SE) image with imposed colors to generate an image with compositional, textural and topographic information. The BSE signal intensity is governed by the density (by means of the atomic number) of the particles and shows a contrast in elemental composition between each particle. The blue color was imposed for high density, highlighting the particles made of heavy metals, and black color for low density, highlighting the graphite and residual binder particles. The SE signal is sensitive toward the topography of the substrate surface and is highlighted through orange colors (like the sun on a mountain). This technique is really practical to see the impurities in a recycling product.
Spectral detective | Dr. Sam Thiele (Helmholtz Institute Freiberg for Resource Technology)
Spectral detective
Source: Dr. Thiele, Samuel Thomas
A billion-year history of tropical seas and ancient mountains is mode visible by hyperspectral imaging in West Greenland. Ancient life precipitated calcium carbonate (blue) from tropical seawater to form a limestone reef that, during a still mysterious process, was partially converted to dolomite (green) before being buried, folded and metamorphosed to make this cliff of marble (green/blue) and amphibolite (red). The distribution of minerals revealed by the false-color hyperspectral image helps disentangle this complex geology to piece together the history of our planet.
Finding rare earths from space | René Booysen (Helmholtz Institute Freiberg for Resource Technology) | Jury Award 3rd Place
Finding rare earths from space
Source: Booysen, René
Green technology, which lays the foundation for the energy transition, requires the sourcing of critical raw materials. In order to find relevant materials, such as rare-earth elements (REE), we need to know where to start looking. Satellite sensors can detect tiny changes in the infrared light not visible to the human eye. This characteristic spectral information can be used to identify rock types over a large area and to target potential resource occurrences. The presented image was acquired by the ASTER-satellite over a 3.600 square kilometre area in northern Namibia. The mesmerizing colors are not the work of photo editing tools, but the result of a principal component analysis (PCA) applied to distinguish the different geological units. Here, the first three PCA bands are displayed in a false color composite. The small tear-drop shape structure in the upper half of the image reveals a carbonite-rich rock complex assopciated with REEs. With the help of satellite data, we can map the rocks and the tectonic deformations that are typically associated with rare earths.
Contact:
Dr. Sara Krause-Solberg
Helmholtz Imaging | Scientific Coordinator
Tel.: +49 40 8998 5527 | sara.krause-solberg@helmholtz-imaging.de
