(Press-News.org)
Kyoto, Japan -- Lead author Yurii Victorovich Kovtun, despite being forced to evacuate the Kharkiv Institute of Physics and Technology amid the current Russia-Ukraine war, has continued to work with Kyoto University to create stable plasmas using microwaves.
Getting plasma just right is one of the hurdles to harnessing the massive amounts of energy promised by nuclear fusion.
Plasmas -- soups of ions and electrons -- must be held at the right density, temperature, and duration for atomic nuclei to fuse together to achieve the desired release of energy.
One recipe involves the use of large, donut-shaped devices with powerful magnets that contain a plasma while carefully aligned microwave generators heat the atomic mixture.
Now, the Institute of Advanced Energy at Kyoto University, together with the Kharkiv Institute and the Max Planck Institute for Plasma Physics have collaborated to create plasmas with fusion-suitable densities, using microwave power with low frequency.
The research team has identified three important steps in the plasma production: lightning-like gas breakdown, preliminary plasma production, and steady-state plasma. The study is being conducted using Heliotron J, the latest iteration of experimental fusion plasma devices at the Institute of Advanced Energy, located on KyotoU's Uji campus in south Kyoto.
"Initially, we did not expect these phenomena in Heliotron J but were surprised to find that plasmas were forming without cyclotron resonance," group leader Kazunobu Nagasaki explains.
Building on decades of experience, Nagasaki's team is exploring the fusion plasma discharges in Heliotron J.
The team injected intense bursts of 2.45-GHz microwave power into a feed gas. Microwave ovens in the home operate at this same frequency but Heliotron J is around 10 times more powerful and concentrated over a few gas atoms.
"Unexpectedly, we found that blasting the microwaves without alignment of Heliotron J's magnetic field created a discharge that ripped electrons from their atoms and produced an especially dense plasma," marvels Nagasaki.
"We are extremely grateful that our colleague could continue supporting the study, despite the war in Ukraine. Our findings about this method to generate plasmas using microwave discharge may simplify fusion research in the future."
###
The paper "Non-Resonant Microwave Discharge Start-Up in Heliotron J" was published on 23rd February 2023 in the journal Problems of Atomic Science and Technology: Plasma Physics at doi: 10.46813/2023-143-003
About Kyoto University
Kyoto University is one of Japan and Asia's premier research institutions, founded in 1897 and responsible for producing numerous Nobel laureates and winners of other prestigious international prizes. A broad curriculum across the arts and sciences at both undergraduate and graduate levels is complemented by numerous research centers, as well as facilities and offices around Japan and the world. For more information please see: http://www.kyoto-u.ac.jp/en
Credit: Nano Pico Science (www.nano-pico-science.com)
END
The opening day of the World Conference of Science Journalists (WCSJ) 2023 in Medellín, Colombia saw hundreds of journalists from 62 countries come together in the stunning setting of the city’s Jardin Botanico.
Over 500 attendees will gather over three days to discuss science journalism, to challenge ideas and to reinforce their professional networks and friendships.
The day began with a keynote on biodiversity delivered by Brigitte Baptiste, a Colombian biologist and expert in biodiversity issues. And it closed with an opening ceremony and vibrant social event for attendees.
Both took place under open skies in the ...
One of the many ways to reduce the energy required for transportation is to make vehicles lighter. High-strength (HS) steels are perfect candidate materials for this purpose, as their higher weight-to-strength ratio allows for the use of less metal to achieve a similar structural integrity. Many automobile companies believe HS steels will be an essential component of various types of cars in the future. However, for this to become a reality, there is a glaring problem that needs to be solved.
When HS steel is exposed to rainwater (H2O) or hydrogen, a phenomenon known as hydrogen embrittlement occurs. Hydrogen atoms diffuse into the lattice ...
A health impact assessment led by the Barcelona Institute for Global Health (ISGlobal), a centre supported by the ”la Caixa” Foundation, has concluded that implementing green corridors throughout the city of Barcelona would result in a “considerable reduction” in mental disorder cases in adult residents as well as in direct and indirect costs associated to said cases. The study was published in the journal Environment International.
It is estimated that mental health disorders ...
A detailed analysis of consumed food showed there is a need to improve diets in long-term care (LTC) homes to make them healthier for residents.
The analysis found that eating more whole grains, plant-based proteins, and plain fruits and vegetables would help residents meet government guidelines and reduce their risk of inflammation.
Researchers at the University of Waterloo developed new artificial intelligence (AI) technology to examine data on food and fluids consumed by more than 600 residents over three days at 32 LTC homes.
Results were compared to recommendations in the 2019 Canada’s Food Guide on healthy eating and expert ...
UNIVERSITY PARK, Pa. — After a building failure due to natural disasters or poor structural design, safety inspectors must enter a structure to assess the damage before occupants can return. Researchers in the Penn State Department of Architectural Engineering studied how building inspectors make their safety assessments, by analyzing their gaze patterns with eye-tracking software. Eventually, the eye-tracking data could be used to code autonomous robots, like drones, to conduct building assessments in place of humans.
The researchers' results were published in Scientific Reports.
“We ...
UNIVERSITY PARK, Pa. — Measuring temperature and nitrogen levels in soil is important for agriculture systems but detecting them apart from one another is difficult to do. Huanyu “Larry” Cheng, James L. Henderson, Jr. Memorial Associate Professor of Engineering Science and Mechanics at Penn State, led researchers in the development of a multi-parameter sensor that can effectively decouple temperature and nitrogen signals so that each can be measured accurately. The results were recently published by Advanced Materials.
“For efficient fertilization, ...
A DNA editing tool adapted by Oak Ridge National Laboratory scientists makes engineering microbes for everything from bioenergy production to plastics recycling easier and faster.
The Serine recombinase-Assisted Genome Engineering, or SAGE system, lets scientists quickly insert and test new DNA designs in a variety of microorganisms. Engineered microbes hold promise for making biofuels, recycling mixed plastics, aiding soil carbon storage and treating health disorders.
“SAGE works in virtually all microorganisms, revolutionizing what we’re able to do with microbes,” ...
Neuroscientists from the Medical University of South Carolina (MUSC) report in Brain Connectivity that they have detected subtle differences in the way the brain functions in older adults with preclinical Alzheimer’s disease (AD).
Adults with preclinical AD have the earliest signs of disease, such as buildup of amyloid-beta proteins in their brains. However, they have no noticeable symptoms of cognitive decline.
The research team, led by Andreana Benitez, Ph.D., and Stephanie Fountain-Zaragoza, Ph.D., used a novel brain imaging analysis technique to construct individualized maps of brain function. They then looked to see if there were ...
Taxes on sugary drinks reduce the risk of gestational diabetes and unhealthy weight gain in pregnant women, reports a new UC San Francisco study of more than 5 million women.
Published by the American Journal of Preventive Medicine, this is the first study to examine how sugar-sweetened beverage (SSB) taxes affect the health of mothers and children immediately before and after birth. Researchers compared mothers who were living in cities that had SSB taxes in effect while they were pregnant to mothers in cities with no SSB taxes. In addition to significantly lowering the risk of diabetes and unhealthy weight gain ...
Bioactive compounds present mostly in fruit and vegetables perform different bodily functions relating to health and well-being. Their effects are considered antioxidant, antidiabetic, antiaging and anticancer, among others.
Many studies are looking for ways to optimize absorption of bioactive compounds by the organism and increase their bioavailability – the proportion that enters the bloodstream after absorption. One way is to coat the compounds with another material and package them on the nanometric scale (a nanometer is a billionth of a meter). Nanoencapsulation, as this technique is known, assures slow release of the compounds so that they take longer to digest and can survive ...
