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Category: particle physics – Page 10

To develop a practical fusion power system, scientists need to fully understand how the plasma fuel interacts with its surroundings. The plasma is superheated, which means some of the atoms involved can strike the wall of the fusion vessel and become embedded. To keep the system working efficiently, it’s important to know how much fuel might be trapped.

“The less fuel is trapped in the wall, the less radioactive material builds up,” said Shota Abe, a staff research physicist at the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL).

Abe is the lead researcher on a study published in Nuclear Materials and Energy. The study looks specifically at how much —thought to be one of the best fuels for —might get stuck in the boron-coated, graphite walls of a doughnut-shaped fusion vessel known as a tokamak. Boron is used in some experimental fusion systems to reduce plasma impurities. However, researchers do not fully understand how a boron coating might impact the amount of fusion fuel that leaves the plasma and becomes embedded in the vessel walls.

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A team of scientists from Princeton University has measured the energies of electrons in a new class of quantum materials and has found them to follow a fractal pattern. Fractals are self-repeating patterns that occur on different length scales and can be seen in nature in a variety of settings, including snowflakes, ferns, and coastlines.

A quantum version of a , known as “Hofstadter’s butterfly,” has long been predicted, but the new study marks the first time it has been directly observed experimentally in a real material. This research paves the way toward understanding how interactions among electrons, which were left out of the theory originally proposed in 1976, give rise to new features in these quantum fractals.

The study was made possible by a recent breakthrough in , which involved stacking and twisting two sheets of carbon atoms to create a pattern of electrons that resembles a common French textile known as a moiré design.

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Scientists are hunting for axions, tiny particles that could solve major physics mysteries, including why neutrons don’t have an electric dipole moment and what dark matter is made of. Using the powerful European XFEL in Hamburg, researchers fired X-rays through special crystals, hoping to witness axions converting into light—a sign of their existence. This pioneering experiment, already competitive with major particle accelerator studies, demonstrates that XFEL technology could be a game-changer in particle physics.

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Dark matter is an elusive type of matter that does not emit, absorb or reflect light and is thus impossible to detect using conventional techniques employed in particle physics. In recent years, groups of physicists worldwide have been trying to observe this matter indirectly using advanced detectors and equipment, by detecting signals other than electromagnetic radiation that could be linked to its activity or interactions with other matter.

Researchers at Tokyo Metropolitan University, PhotoCross Co. Ltd, Kyoto Sangyo University and other collaborating institutions recently released the findings of the first search for dark matter that relied on data collected by WINERED, a near-infrared and high-dispersion spectrograph mounted on a in Chile.

Their paper, published in Physical Review Letters, sets the most stringent constraints to date on the lifetime of dark matter particles with masses between 1.8 and 2.7 eV.

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From integrated photonics to quantum information science, the ability to control light with electric fields—a phenomenon known as the electro-optic effect—supports vital applications such as light modulation and frequency transduction. These components rely on nonlinear optical materials, in which light waves can be manipulated by applying electric fields.

Conventional nonlinear optical materials such as lithium niobate have a large electro-optic response but are hard to integrate with silicon devices. In the search for silicon-compatible materials, aluminum scandium nitride (AlScN), which had already been flagged as an excellent piezoelectric—referring to a material’s ability to generate electricity when pressure is applied, or to deform when an electric field is applied—has come to the fore. However, better control of its properties and means to enhance its electro-optic coefficients are still required.

Researchers in Chris Van de Walle’s computational materials group at UC Santa Barbara have now uncovered ways to achieve these goals. Their study, published in Applied Physics Letters, explains how adjusting the material’s atomic structure and composition can boost its performance. Strong electro-optic response requires a large concentration of scandium—but the specific arrangement of the scandium atoms within the AlN crystal lattice matters.

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RESEARCHERS at Rice University, US have discovered a green process which can quickly and cheaply produce graphene from almost any carbon source, including coal, mixed plastic waste, biomass, and waste food. It could facilitate a reduction in the environmental impact of concrete and other building materials.

Graphene is the strongest known material. It is comprised of a single layer of carbon atoms arranged in a two-dimensional hexagonal lattice, in which one atom forms each vertex. A tiny amount of graphene can significantly enhance the properties of materials such as plastics, paints, composites, wood composites, concrete, metals, and lubricant. However, it is expensive to manufacture, so has limited industrial applications.

The process discovered at Rice employs flash Joule heating is a process where an electric current is passed through a conductor to produce heat. Using a custom reactor, the Rice researchers can produce graphene in 10 ms. The carbon source is placed between two electrodes and 200 V is applied in a short electrical pulse, heating the material to more than 3,000K (2726.9°C). Non-carbon elements sublime and the remaining carbon atoms reconstruct into carbon.

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Scientists have found a new way to control quantum information using a special material, chromium sulfide bromide.

It can store and process data in multiple forms, but its magnetic properties are the real game-changer. By adjusting its magnetization, researchers can confine excitons—quantum particles that carry information—allowing for longer-lasting quantum states and new ways to process data.

Quantum “Miracle Material” Enables Magnetic Switching.

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Researchers at the University of Bayreuth have developed a method that makes objects on a magnetic field invisible within a particle stream. Until now, this so-called cloaking had only been studied for waves such as light or sound. They report their results in Nature Communications.

Making objects invisible is no longer a purely fictional idea from fantasy or sci-fi films. At least to some extent, cloaking also works in research: manipulating objects in such a way that they become invisible to certain waves such as light or sound.

The Bayreuth researchers are extending cloaking to particle motions. Cloaking for particle streams on miniaturized chemical laboratories, so-called lab-on-a-chip devices, can help to transport active ingredients in a targeted manner without exposing them to undesirable premature chemical reactions.

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Rain can freefall at speeds of up to 25 miles per hour. If the droplets land in a puddle or pond, they can form a crown-like splash that, with enough force, can dislodge any surface particles and launch them into the air.

Now MIT scientists have taken high-speed videos of droplets splashing into a deep pool, to track how the fluid evolves, above and below the water line, frame by millisecond frame. Their work could help to predict how spashing droplets, such as from rainstorms and irrigation systems, may impact watery surfaces and aerosolize surface particles, such as pollen on puddles or pesticides in agricultural runoff.

The team carried out experiments in which they dispensed water droplets of various sizes and from various heights into a pool of water. Using high-speed imaging, they measured how the liquid pool deformed as the impacting droplet hit the pool’s surface.

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The Standard Model ℠, the main physics framework describing elementary particles and the forces driving them, outlines key patterns in physical interactions referred to as gauge symmetries. One of the symmetries it describes is the so-called UY hypercharge: a gauge symmetry that contributes to the electric charge of particles before electromagnetic and weak forces become distinct (i.e., before the electroweak phase transition).

Researchers at Universidad Autónoma de Madrid’s Theoretical Physics Department (DFT) and Instituto de Física Teórica (IFT) recently carried out a study investigating how the conditions present in the early universe could prompt the spontaneous breaking of this gauge symmetry, linking this phenomenon to certain models of neutrino mass generation known as radiative neutrino mass models. Their paper, published in Physical Review Letters, specifically builds on a theoretical framework called the Zee-Babu model, an extension of the SM explaining neutrino mass generation.

“In the SM, the spontaneously broken electroweak gauge symmetry, which governs the electromagnetic and weak interactions of nature, was restored in the universe’s first instants, when the universe’s temperature was higher than the electroweak energy scale,” Prof. Jose Miguel No, Luca Merlo, Alvaro Lozano-Onrubia and Sergio López-Zurdo told Phys.org.

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