Japan’s JT-60SA Generates First Plasma As World’s Largest Superconducting Tokamak Fusion Reactor

December 6, 2023 by Maya Posch 35 Comments

Comparison of toroidal field (TF) coils from JET, JT-60SA and ITER (Credit: QST)

Japan’s JT-60SA fusion reactor project announced first plasma in October of this year to denote the successful upgrades to what is now the world’s largest operational, superconducting tokamak fusion reactor. First designed in the 1970s as Japan’s Breakeven Plasma Test Facility, the JT-60SA tokamak-based fusion reactor is the latest upgrade to the original JT-60 design, following two earlier upgrades (-A and -U) over its decades-long career. The most recent upgrade matches the Super Advanced meaning of the new name, as the new goal of the project is to investigate advanced components of the global ITER nuclear fusion project.

Originally the JT-60SA upgrade with superconducting coils was supposed to last from 2013 to 2020, with first plasma that same year. During commissioning in 2021, a short circuit in the poloidal field coils caused a lengthy investigation and repair, which was completed earlier this year. Although the JT-60SA is only using hydrogen and later deuterium as its fuel rather than the deuterium-tritium (D-T) mixture of ITER, it nevertheless has a range of research objectives that allow for researchers to study many aspects of the ITER fusion reactor while the latter is still under construction.

Since the JT-60SA also has cooled divertors, it can sustain plasma for up to 100 seconds, to study various field configurations and the effect this has on plasma stability, along with a range of other parameters. Along with UK’s JET, China’s HL-2M and a range of other tokamaks at other facilities around the world, this should provide future ITER operators with significant know-how and experience long before that tokamak will generate its first plasma.

Anthrobots can promote gap closures on scratched live neuronal monolayers. (Credit: Gumuskaya et al., 2023)

Anthrobots: Tiny Robots From Tracheal Epithelium Cells That Can Fix Neural Damage

December 6, 2023 by Maya Posch 10 Comments

Although we often regard our own bodies and those of the other multicellular organisms around us as a singular entity, each cell that makes up our body is its own, nano-robot. One long-existing question was whether these cells can be used for other tasks — like biological robots — after they have specialized into a specific tissue type, with a recent study by [Gizem Gumuskaya] and colleagues in Advanced Science (with Nature news coverage) indicating a potential intriguing use of adult human epithelial cells recovered from the trachea.

Human bronchial epithelial cells self-construct into multicellular motile living architectures. (Credit: Gumuskaya et al., 2023)

After extraction, these adult cells were kept in an extracellular matrix (ECM, Matrigel) in conditions promoting cell division, followed by ECM dissolution after 14 days and subsequent culturing of the spherical clumps of cells that had thus formed in a water-based, low-viscosity environment. This environment, along with the addition of retinoic acid promoted the development of outward-facing cilia, rather than the typical inward type with a gel-based ECM.

These spheroids (anthrobots, referencing their human origin) generally showed the ability to move using these cilia, with the direction largely determined by the symmetry of the sphere. Multiple of these motile spheroids were then placed on a layer of human neural tissue, in which a scratch had damaged a number of the neurons to form a gap. The anthrobots grouped together over the course of days to form a bridge across the gap, with the neural tissue observed to regrow underneath this bridge, a behavior that could not be repeated by using a dummy support consisting out of agarose on another neural sample, indicating that it is this living bridge that enabled neural regeneration.

Although the researchers rightfully indicate that they are uncertain which factors actually induce this restorative effect in the neurons, it offers exciting glimpses into a potential feature where neural damage is easily repaired, and biological robots made from our own cells can be assembled to perform a variety of tasks.

Radio Emissions Over Sunspots Challenge Models Of Stellar Magnetism

December 1, 2023 by Donald Papp 1 Comment

Sustained radio emissions originating from high over a sunspot are getting researchers thinking in new directions. Unlike solar radio bursts — which typically last only minutes or hours — these have persisted for over a week. They resemble auroral radio emissions observed in planetary magnetospheres and some stars, but seeing them from about 40,000 km above a sunspot is something new. They don’t seem tied to solar flare activity, either.

The signals are thought to be the result of electron cyclotron maser (ECM) emissions, which involves how electrons act in converging geometries of magnetic fields. These prolonged emissions challenge existing models and ideas about how solar and stellar magnetic processes unfold, and understanding it better could lead to a re-evaluation of existing astrophysical models. Perhaps even leading to new insights into the behavior of magnetic fields and energetic particles.

This phenomenon was observed from our very own sun, but it has implications for better understanding distant stellar bodies. Speaking of our sun, did you know it is currently in it’s 25th Solar Cycle? Check out that link for a reminder of the things the awesome power of our local star is actually capable of under the right circumstances.

Crystal structure of Cr2Te3 thin films. (Credit: Hang Chi et al. 2023)

Chromium(III) Telluride As Ferromagnetic Material With Tunable Anomalous Hall Effect

November 29, 2023 by Maya Posch 7 Comments

Chromium(III) Telluride (Cr₂Te₃) is an interesting material for (ferro)magnetic applications, with Yao Wen and colleagues reporting in a 2020 Nano Letters paper that they confirmed it to show spontaneous magnetization at a thickness of less than fifty nanometers, at room temperature. Such a 2D ferromagnet could be very useful for spintronics and other applications. The confirmation of magnetization is performed using a variety of methods, including measuring the Hall Effect (HE) and the Anomalous Hall Effect (AHE), the latter of which is directly dependent on the magnetization of the material, rather than an externally applied field.

More recently, in a June 2023 article by Hang Chi and colleagues in Nature Communications, it is described how such epitaxially obtained Cr₂Te₃ films show a distinct change in the AHE (in the form of sign reversal) depending on the strain induced by the interface with the various types of substrates (Al₂O₃, SrTiO₃) and the temperature, likely owing to the different thermal expansion rates of the film and substrate. Underlying this change in the observed AHE is the Berry phase and the related curvature. This is a phenomenon that was also noted by Quentin Guillet and colleagues in their 2023 article in Physical Review Materials, effectively independently confirming the AHE

Using Cr₂Te₃ in combination with the appropriate substrate might ultimately lead to spintronics-based memory and other devices, even if such applications will still take considerable R&D.

Top image: Crystal structure of Cr₂Te₃ thin films. (Credit: Hang Chi et al. 2023)

CAR T Cell Immunotherapy And The Quiet Hope For A Universal Cancer Treatment

November 27, 2023 by Maya Posch 1 Comment

All of us have to deal with the looming threat of developing cancer during our lifetime, no matter how good our genetics are, or how healthy our lifestyle is. Despite major improvements to the way that we treat and even cure cases of cancer, the reality today is that not all types of cancer are treatable, in many cases there’s the likelihood that one day it will return even after full remission, and chemotherapy in particular comes with potential life-long health issues. Of the most promising new and upcoming treatments, immunotherapy, is decidedly among the most interesting.

With this approach, it is the body’s own immune system that is taught to attack those cancer cells, requiring little more than a few tweaks to T-cells harvested from the patient’s body, after which they’re sent on their merry cancer-killing way. Yet as simple as this sounds, finding the right characteristics which identify the cancerous cells, and getting a solid and long-lasting immune response is a tough challenge. Despite highly promising results with immunotherapy treatment for non-solid cancers like leukemia – that have resulted in almost miraculous cures – translating this success to other cancer types has so far remained elusive.

New research now shows that changing some characteristics of these modified (chimeric antigen receptors, or CAR) T-cells may be key to making them significantly more long-lived and effective within a patient’s body. Is this the key to making immunotherapy possible for many more cancers?

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The Slow March Of Sodium-Ion Batteries To Compete With Lithium-Ion

November 26, 2023 by Maya Posch 56 Comments

The process of creating new battery chemistries that work better than existing types is a slow and arduous one. Not only does it know more failures than successes, it’s rare that a once successful type gets completely phased out, which is why today we’re using lead-acid, NiMH, alkaline, lithium, zinc-air, lithium-ion and a host of other battery types alongside each other. For one of the up-and-coming types in the form of sodium (Na)-based batteries the same struggles are true as it attempts to hit the right balance between anode, cathode and electrolyte properties. A pragmatic solution here involves Prussian Blue for the cathode and hard carbon for the anode, as is the case with Swedish Northvolt’s newly announced sodium-ion battery (SIB) which is sampling next year.

Commercialization of different SIB battery chemistries by various companies. (Credit: Yadav et al. 2022) — Commercialization of different SIB battery chemistries by various companies. (Credit: Yadav et al., 2022)

The story of SIBs goes back well over a decade, with a recent review article by Poonam Yadav and colleagues in Oxford Open Materials Science providing a good overview of the many types of anodes, cathodes and electrolytes which have been attempted and the results. One of the issues that prevents an SIB from directly using the carbon-based anodes employed with today’s lithium-ion batteries (LIB) is its much larger ionic radius that prevents intercalation without altering the carbon material to accept Na+ ions.

This is essentially where the hard carbon (HC) anode used by a number of SIB-producing companies comes into play, which has a far looser structure that does accept these ions and thus can be used with SIBs. The remaining challenges lie then with the electrolyte – which is where an organic form is the most successful – and the material for the sodium-containing cathode.

Although oxide forms and even sodium vanadium fluorophosphate (NVPF) are also being used, Prussian Blue analogs (PBAs) are attractive for being very low-cost and effective as cathode material once processed. An efficient way to process PB into fully sodiated and reduced Prussian White was demonstrated a few years ago, followed by successive studies backing up this assessment.

Although SIBs are seeing limited commercial use at this point, signs are that if it can be commercialized for the consumer market, it would have similar capacity as current LIBs, albeit with the potential to be cheaper, more durable and easier to recycle.

Harvard SETI Project Helps ID Mystery Sound

November 23, 2023 by Tom Nardi 27 Comments

Last month, thousands of people in New Hampshire took to social media to report an explosion in the sky that was strong enough to rattle windows. Naturally aliens were blamed by some, while cooler heads theorized it may have been a sonic boom from a military aircraft. But without any evidence, who could say?

Luckily for concerned residents, this was precisely the sort of event Harvard’s Galileo Project was designed to investigate. Officially described as a way to search for “technological signatures of Extraterrestrial Technological Civilizations (ETCs)”, the project keeps a constant watch on the sky with a collection of cameras and microphones. With their gear, the team was able to back up the anecdotal reports with with hard data.

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