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Scientists develop a new tool for measuring radio waves in fusion plasmas – Newswise

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Newswise — Scientists seeking to bring to Earth the fusion energy that drives the sun and stars use radio frequency (RF) waves — the same waves that bring radio and television into homes — to heat and drive current in the plasma that fuels fusion reactions. Scientists now have developed a path-setting way to measure the waves that could be used to validate predictions of their impact, setting the stage for enhanced future experiments that could result in bringing energy from fusion to Earth.

Potential breakthrough

The potential breakthrough, led by researchers at the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL), could lead to follow-up experiments on the National Spherical Tokamak Experiment-Upgrade (NSTX-U), the flagship fusion experiment at PPPL that is undergoing repair, as well as other fusion facilities around the world. “If our method turns out to work it would be a very useful tool for many fusion reactors,” said Grant Rutherford, a first-year graduate student at the Massachusetts Institute of Technology (MIT) and lead author of a paper in the Review of Scientific Instruments that he wrote as a Brown University DOE Science Undergraduate Laboratory Intern (SULI) at PPPL.

Key to predicting the impact of RF waves is measuring the fluctuations, or swings, they create in the density of fusion plasmas. “Once we have those fluctuations we would be able to work backwards to see what those RF fields were that created the fluctuations,” Rutherford said.

However, the high frequency of RF waves causes the swings to occur too rapidly to measure. So the researchers created a “beat wave” by launching two waves at different frequencies, a technique that produced measurable swings. “If we were able to both create a beat wave fluctuation and measure it, we would have a new tool for validating predictions for RF heating and current drive,” Rutherford explained.

Such measurements would have wide-ranging benefits. For example, they could facilitate study of the performance of RF wave actuators, said PPPL physicist Nicola Bertelli, a co-author of the paper, and could enable validation of RF calculation tools developed throughout the fusion community. Moreover, said David Smith, a University of Wisconsin physicist and co-author of the paper, “Our calculations provide an initial assessment of the technique and motivate follow-up experiments on NSTX-U.”

Fusion reactions combine light elements in the form of plasma —  the hot, charged state of matter composed of free electrons and atomic nuclei that makes up 99 percent of the visible universe — to generate massive amounts of energy. Reproducing and controlling this process on Earth would create a virtually inexhaustible supply of safe and clean power to generate electricity. Fusion could become a major contributor to the U.S. transition from fossil fuels to a low-carbon source of electrical generation.

Testing the technique

Rutherford and co-authors tested their technique by creating a synthetic version of a 2D beam emission spectroscopy (BES) diagnostic to evaluate simulated RF injections into the plasma. Their aim was to understand and improve the ability to measure the RF field waves that create the swings. 

Going forward, “We’re hoping that by increasing our ability to measure, we will increase our ability to understand heating and current drive processes, but we’re leaving that to future work,” Rutherford said. Such work could also show whether the BES diagnostic the scientists based their model on could measure the density swings in actual fusion plasmas, or whether some other diagnostic would do the critical job better. 

The DOE Office of Science (FES) supported this work.

PPPL, on Princeton University’s Forrestal Campus in Plainsboro, N.J., is devoted to creating new knowledge about the physics of plasmas — ultra-hot, charged gases — and to developing practical solutions for the creation of fusion energy. The Laboratory is managed by the University for the U.S. Department of Energy’s Office of Science, which is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, visit energy.gov/science.

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The body of a Ugandan Olympic athlete who was set on fire by her partner is received by family

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NAIROBI, Kenya (AP) — The body of Ugandan Olympic athlete Rebecca Cheptegei — who died after being set on fire by her partner in Kenya — was received Friday by family and anti-femicide crusaders, ahead of her burial a day later.

Cheptegei’s family met with dozens of activists Friday who had marched to the Moi Teaching and Referral Hospital’s morgue in the western city of Eldoret while chanting anti-femicide slogans.

She is the fourth female athlete to have been killed by her partner in Kenya in yet another case of gender-based violence in recent years.

Viola Cheptoo, the founder of Tirop Angels – an organization that was formed in honor of athlete Agnes Tirop, who was stabbed to death in 2021, said stakeholders need to ensure this is the last death of an athlete due to gender-based violence.

“We are here to say that enough is enough, we are tired of burying our sisters due to GBV,” she said.

It was a somber mood at the morgue as athletes and family members viewed Cheptegei’s body which sustained 80% of burns after she was doused with gasoline by her partner Dickson Ndiema. Ndiema sustained 30% burns on his body and later succumbed.

Ndiema and Cheptegei were said to have quarreled over a piece of land that the athlete bought in Kenya, according to a report filed by the local chief.

Cheptegei competed in the women’s marathon at the Paris Olympics less than a month before the attack. She finished in 44th place.

Cheptegei’s father, Joseph, said that the body will make a brief stop at their home in the Endebess area before proceeding to Bukwo in eastern Uganda for a night vigil and burial on Saturday.

“We are in the final part of giving my daughter the last respect,” a visibly distraught Joseph said.

He told reporters last week that Ndiema was stalking and threatening Cheptegei and the family had informed police.

Kenya’s high rates of violence against women have prompted marches by ordinary citizens in towns and cities this year.

Four in 10 women or an estimated 41% of dating or married Kenyan women have experienced physical or sexual violence perpetrated by their current or most recent partner, according to the Kenya Demographic and Health Survey 2022.

The Canadian Press. All rights reserved.

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The ancient jar smashed by a 4-year-old is back on display at an Israeli museum after repair

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TEL AVIV, Israel (AP) — A rare Bronze-Era jar accidentally smashed by a 4-year-old visiting a museum was back on display Wednesday after restoration experts were able to carefully piece the artifact back together.

Last month, a family from northern Israel was visiting the museum when their youngest son tipped over the jar, which smashed into pieces.

Alex Geller, the boy’s father, said his son — the youngest of three — is exceptionally curious, and that the moment he heard the crash, “please let that not be my child” was the first thought that raced through his head.

The jar has been on display at the Hecht Museum in Haifa for 35 years. It was one of the only containers of its size and from that period still complete when it was discovered.

The Bronze Age jar is one of many artifacts exhibited out in the open, part of the Hecht Museum’s vision of letting visitors explore history without glass barriers, said Inbal Rivlin, the director of the museum, which is associated with Haifa University in northern Israel.

It was likely used to hold wine or oil, and dates back to between 2200 and 1500 B.C.

Rivlin and the museum decided to turn the moment, which captured international attention, into a teaching moment, inviting the Geller family back for a special visit and hands-on activity to illustrate the restoration process.

Rivlin added that the incident provided a welcome distraction from the ongoing war in Gaza. “Well, he’s just a kid. So I think that somehow it touches the heart of the people in Israel and around the world,“ said Rivlin.

Roee Shafir, a restoration expert at the museum, said the repairs would be fairly simple, as the pieces were from a single, complete jar. Archaeologists often face the more daunting task of sifting through piles of shards from multiple objects and trying to piece them together.

Experts used 3D technology, hi-resolution videos, and special glue to painstakingly reconstruct the large jar.

Less than two weeks after it broke, the jar went back on display at the museum. The gluing process left small hairline cracks, and a few pieces are missing, but the jar’s impressive size remains.

The only noticeable difference in the exhibit was a new sign reading “please don’t touch.”

The Canadian Press. All rights reserved.

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B.C. sets up a panel on bear deaths, will review conservation officer training

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VICTORIA – The British Columbia government is partnering with a bear welfare group to reduce the number of bears being euthanized in the province.

Nicholas Scapillati, executive director of Grizzly Bear Foundation, said Monday that it comes after months-long discussions with the province on how to protect bears, with the goal to give the animals a “better and second chance at life in the wild.”

Scapillati said what’s exciting about the project is that the government is open to working with outside experts and the public.

“So, they’ll be working through Indigenous knowledge and scientific understanding, bringing in the latest techniques and training expertise from leading experts,” he said in an interview.

B.C. government data show conservation officers destroyed 603 black bears and 23 grizzly bears in 2023, while 154 black bears were killed by officers in the first six months of this year.

Scapillati said the group will publish a report with recommendations by next spring, while an independent oversight committee will be set up to review all bear encounters with conservation officers to provide advice to the government.

Environment Minister George Heyman said in a statement that they are looking for new ways to ensure conservation officers “have the trust of the communities they serve,” and the panel will make recommendations to enhance officer training and improve policies.

Lesley Fox, with the wildlife protection group The Fur-Bearers, said they’ve been calling for such a committee for decades.

“This move demonstrates the government is listening,” said Fox. “I suspect, because of the impending election, their listening skills are potentially a little sharper than they normally are.”

Fox said the partnership came from “a place of long frustration” as provincial conservation officers kill more than 500 black bears every year on average, and the public is “no longer tolerating this kind of approach.”

“I think that the conservation officer service and the B.C. government are aware they need to change, and certainly the public has been asking for it,” said Fox.

Fox said there’s a lot of optimism about the new partnership, but, as with any government, there will likely be a lot of red tape to get through.

“I think speed is going to be important, whether or not the committee has the ability to make change and make change relatively quickly without having to study an issue to death, ” said Fox.

This report by The Canadian Press was first published Sept. 9, 2024.

The Canadian Press. All rights reserved.

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