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Scientists Continue to Trace the Origin of the Mysterious “Amaterasu” Cosmic Ray Particle

When the Amaterasu particle entered Earth’s atmosphere, the TAP array in Utah recorded an energy level of more than 240 exa-electronvolts (EeV). Such particles are exceedingly rare and are thought to originate in some of the most extreme cosmic environments. At the time of its detection, scientists were not sure if it was a proton, a light atomic nucleus, or a heavy (iron) atomic nucleus. Research into its origin pointed toward the Local Void, a vast region of space adjacent to the Local Group that has few known galaxies or objects.

This posed a mystery for astronomers, as the region is largely devoid of sources capable of producing such energetic particles. Reconstructing the energy of cosmic-ray particles is already difficult, making the search for their sources using statistical models particularly challenging. Capel and Bourriche addressed this by combining advanced simulations with modern statistical methods (Approximate Bayesian Computation) to generate three-dimensional maps of cosmic-ray propagation and their interactions with magnetic fields in the Milky Way.

The IceCube experiment is ready to uncover more secrets of the universe

The name “IceCube” not only serves as the title of the experiment, but also describes its appearance. Embedded in the transparent ice of the South Pole, a three-dimensional grid of more than 5,000 extremely sensitive light sensors forms a giant cube with a volume of one cubic kilometer. This unique arrangement serves as an observatory for detecting neutrinos, the most difficult elementary particles to detect.

In order to detect neutrinos, they must interact with matter, creating charged particles whose light can be measured. These light measurements can be used to determine information about the properties of neutrinos. However, the probability of neutrinos interacting with matter is extremely low, so they usually pass through it without leaving a trace, which makes their detection considerably more difficult.

For this reason, a large detector volume is required to increase the probability of interaction, and state-of-the-art technology is crucial for detecting such rare interactions.

IceCube upgrade adds six deep sensor strings to detect lower-energy neutrinos

Since 2010, the IceCube Observatory at the Amundsen-Scott South Pole Station has been delivering groundbreaking measurements of high-energy cosmic neutrinos. It consists of many detectors embedded in a volume of Antarctic ice measuring approximately one cubic kilometer. IceCube has now been upgraded with new optical modules to enable it to measure lower-energy neutrinos as well. Researchers at the Karlsruhe Institute of Technology (KIT) made a significant contribution to this expansion.

IceCube serves to measure high-energy neutrinos in an ice volume of one cubic kilometer. As neutrinos themselves do not emit any signals, the tracks of muons and other secondary particles are measured precisely. Muons are elementary particles sometimes produced by the interaction of neutrinos with ice. Contrary to neutrinos, muons carry an electric charge. On their way through the ice, they produce a characteristic light cone, which is detected by highly sensitive detectors.

Now, 51 researchers from around the world have installed six new strings of novel sensors up to 2,400 meters deep into the eternal ice, thereby expanding the IceCube experiment to also measure low-energy neutrinos.

AI captures particle accelerator behavior to optimize machine performance

Keeping high-power particle accelerators at peak performance requires advanced and precise control systems. For example, the primary research machine at the U.S. Department of Energy’s Thomas Jefferson National Accelerator Facility features hundreds of fine-tuned components that accelerate electrons to 99.999% the speed of light.

The electrons get this boost from radiofrequency waves within a series of resonant structures known as cavities, which become superconducting at temperatures colder than deep space.

These cavities form the backbone of Jefferson Lab’s Continuous Electron Beam Accelerator Facility (CEBAF), a unique DOE Office of Science user facility supporting the research of more than 1,650 nuclear physicists from around the globe. CEBAF also holds the distinction of being the world’s first large-scale installation and application of this superconducting radiofrequency (SRF) technology.

Nanolaser on a chip could cut computer energy use in half

Researchers at DTU have developed a nanolaser that could be the key to much faster and much more energy-efficient computers, phones, and data centers. The technology offers the prospect of thousands of the new lasers being placed on a single microchip, thus opening a digital future where data is no longer transmitted using electrical signals, but using light particles, photons. The invention has been published in the journal Science Advances.

“The nanolaser opens up the possibility of creating a new generation of components that combine high performance with minimal size. This could be in information technology, for example, where ultra-small and energy-efficient lasers can reduce energy consumption in computers, or in the development of sensors for the health care sector, where the nanolaser’s extreme light concentration can deliver high-resolution images and ultrasensitive biosensors,” says DTU professor Jesper Mørk, who co-authored the paper together with, among others, Drs. Meng Xiong and Yi Yu from DTU Electro.

Driven electrolytes are agile and active at the nanoscale

Technologies for energy storage as well as biological systems such as the network of neurons in the brain depend on driven electrolytes that are traveling in an electric field due to their electrical charges. This concept has also recently been used to engineer synthetic motors and molecular sensors on the nanoscale or to explain biological processes in nanopores. In this context, the role of the background medium, which is the solvent, and the resulting hydrodynamic fluctuations play an important role. Particles in such a system are influenced by these stochastic fluctuations, which effectively control their movements.

“When we imagine the environment inside a driven electrolyte at the nanoscale, we might think of a calm viscous medium in which ions move due to the electric field and slowly diffuse around. This new study reveals that this picture is wrong: the environment resembles a turbulent sea, which is highly nontrivial given the small scale,” explains Ramin Golestanian, who is director of the Department of Living Matter Physics at MPI-DS, and author of the study published in Physical Review Letters.

The research uncovers how the movement of the ions creates large-scale fluctuating fluid currents that stir up the environment and lead to fast motion of all the particles that are immersed in the environment, even if they are not charged.

Cutting down on quantum-dot crosstalk: Precise measurements expose a new challenge

Devices that can confine individual electrons are potential building blocks for quantum information systems. But the electrons must be protected from external disturbances. RIKEN researchers have now shown how quantum information encoded into a so-called quantum dot can be negatively affected by nearby quantum dots. This has implications for developing quantum information devices based on quantum dots.

Quantum computers process information using so-called qubits: physical systems whose behavior is governed by the laws of quantum mechanics. An electron, if it can be isolated and controlled, is one example of a qubit platform with great potential.

One way of controlling an electron is to use a quantum dot. These tiny structures trap charged particles using electric fields at the tips of metal electrodes separated by just a few tens of nanometers.

A New Way to Build 2D Materials Without Harsh Chemicals Pays Off Big

MXenes are an emerging class of two-dimensional materials whose properties depend sensitively on the atoms bound to their surfaces. A new synthesis approach now allows researchers to control these surface terminations with unprecedented precision. First identified in 2011, MXenes are a fast-expan

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