Despite technical setbacks concerning key tokamak components, construction of the world's largest fusion experiment machine, the ITER Tokamak, continues in the department of Bouches-du-Rhone in southern France.

ITER stands for International Thermonuclear Experimental Reactor, and tokamak is a magnetic confinement device being developed to produce controlled thermonuclear fusion power.

"We are in the process of recovery from the issues in vacuum vessel sectors (dimensional non-conformities) and thermal shields (stress corrosion cracks in cooling pipes). We are on a good track," ITER Director General Pietro Barabaschi told Xinhua in a recent interview.

SETBACKS WILL BE OVERCOME

In the assembly building adjacent to the tokamak complex, work on the massive components of the ITER device continues in parallel with repair work that started in July.

In this vast workshop, where components are prepared before they are transported to the tokamak pit for installation, the faulty components already installed are being lifted out to be disassembled in order to prepare them for repairs.

"These technical setbacks are not fundamental. They are issues that will be overcome. It's not unusual but actually quite normal to have some setbacks in a project of this kind," Barabaschi said.

The 58-year-old Italian, who joined the ITER team in 1993 and began his tenure as director general of the ITER Organization in October 2022, stressed that "ITER is an extremely challenging project."

Conceived as the last experimental step to prove the feasibility of fusion as a large-scale and carbon-free source of energy based on the same principle that powers the Sun and the stars, ITER is designed to be the world's largest tokamak, with ten times the plasma volume of the largest tokamak operating today.

Three conditions must be fulfilled to achieve fusion in a laboratory: very high temperature (on the order of 150,000,000 degrees Celsius); sufficient plasma particle density (to increase the likelihood that collisions do occur); and sufficient confinement time (to hold the plasma, which has a propensity to expand, within a defined volume).

MANY RISKS AHEAD

The ITER Tokamak will weigh 23,000 tonnes, equal to three Eiffel Towers. The vacuum vessel alone, with its ports, blanket and diverter, weighs 8,000 tonnes. Approximately one million components will be integrated into this complex machine.

Also called the world's largest "artificial Sun," the ITER project has been a decades-long collaboration of its seven members -- China, the European Union, India, Japan, South Korea, Russia and the United States.

"A lot of key components have been delivered. Very important elements that are needed to start up the machine are available," Barabaschi said. "We are well ahead of half of the marathon. We have the finishing line in sight."

"It's not simply a marathon where you know the path and you want to keep up the pace with sustained motivation and determination," he explained. "It's navigation and exploration, which means we venture into an adventure, with many, many risks ahead."

ITER's previous target was to create the plasma by 2025. The duration and cost of the ongoing repairs cannot, at this stage, be precisely estimated. According to the director general, the situation will become clear by mid-2024 as his organization is preparing a new cost and schedule baseline for approval by council meeting at that time.

NOT JUST ITER

The electro-mechanical engineer who has dedicated virtually his entire career to fusion research believes that ITER will remain as the center of the growth of a fusion industry as global enthusiasm about the development of fusion energy reaches an all-time high.

"In the future of fusion, essentially driven by power intensity considerations, reactors will have to be relatively large, the size of ITER or maybe even larger," Barabaschi explained. "Only ITER can provide the experience of tokamak or a complex research infrastructure for future fusion of this size."

He welcomed the increase in public and private investment in fusion. "Fusion is not just ITER. Many others joining the fusion race is always good news. The more the merrier."

"ITER will remain as the center of the seven members' fusion research program. Then, the rest, particularly the investment from the private sector, we should cooperate with them to achieve our objective in the most effective way," he said.

KEY ROLE OF MATERIAL

Barabaschi also highlighted the key role material development plays in the success of fusion. "We can develop plasma, get the fire started, maybe tame the fire and make sure that it produces energy. But then we will need the materials that can take the energy of this fire," he said.

"An energy-producing fusion reactor would need very strong materials that can withstand the radiation coming from the plasma. If we don't take care of that, this exploration will not be leading to the final objective," Barabaschi said. ■

This photo taken on Nov. 23, 2023 shows the assembly building on the construction site of the ITER Tokamak, the world's largest fusion experiment machine, in Saint-Paul-lez-Durance, France. (Xinhua/Gao Jing)

This photo taken on Nov. 24, 2023 shows the assembly building on the construction site of the ITER Tokamak, the world's largest fusion experiment machine, in Saint-Paul-lez-Durance, France. (Xinhua/Gao Jing)

A vast device is seen at a preassembly hall of the world's largest fusion experiment machine, the ITER Tokamak, in St Paul-Lez-Durance, France, Nov. 23, 2023. (Xinhua/Gao Jing)

Technicians check faulty vacuum vessel sectors in the vast preassembly hall on the construction site of the ITER Tokamak in St Paul-Lez-Durance, southern France, Nov. 23, 2023. (Xinhua/Gao Jing)

Technicians check faulty vacuum vessel sectors in the vast preassembly hall on the construction site of the ITER Tokamak in St Paul-Lez-Durance, southern France, Nov. 23, 2023. (Xinhua/Gao Jing)

People work at a preassembly hall of the world's largest fusion experiment machine, the ITER Tokamak, in St Paul-Lez-Durance, France, Nov. 23, 2023. (Xinhua/Gao Jing)

Technicians check faulty vacuum vessel sectors in the vast preassembly hall on the construction site of the ITER Tokamak in St Paul-Lez-Durance, southern France, Nov. 24, 2023. (Xinhua/Gao Jing)

This photo taken on Nov. 23, 2023 shows the assembly building on the construction site of the ITER Tokamak, the world's largest fusion experiment machine, in Saint-Paul-lez-Durance, France. (Xinhua/Gao Jing)

This photo taken on Nov. 23, 2023 shows the tokamak pit on the construction site of the ITER Tokamak in St Paul-Lez-Durance, southern France. (Xinhua/Gao Jing)

The world's largest iceberg is on the move for the first time in more than three decades, scientists said on Friday. 

At almost 4,000 square km (1,500 square miles), the Antarctic iceberg called A23a is roughly three times the size of New York City. 

Since calving off West Antarctica's Filchner-Ronne Ice Shelf in 1986, the iceberg — which once hosted a Soviet research station — has largely been stranded after its base became stuck on the floor of the Weddell Sea. 

Not anymore. Recent satellite images reveal that the berg, weighing nearly a trillion metric tonnes, is now drifting quickly past the northern tip of the Antarctic Peninsula, aided by strong winds and currents. 

It's rare to see an iceberg of this size on the move, said British Antarctic Survey glaciologist Oliver Marsh, so scientists will be watching its trajectory closely. 

As it gains steam, the colossal berg will likely be launched into the Antarctic Circumpolar Current. This will funnel it toward the Southern Ocean on a path known as "iceberg alley" where others of its kind can be found bobbing in dark waters. 

Why the berg is making a run for it now remains to be seen. 

"Over time it's probably just thinned slightly and got that little bit of extra buoyancy that's allowed it to lift off the ocean floor and get pushed by ocean currents," said Marsh. A23a is also among the world's oldest icebergs. 

It's possible A23a could again become grounded at South Georgia island. That would pose a problem for Antarctica's wildlife. Millions of seals, penguins, and seabirds breed on the island and forage in the surrounding waters. Behemoth A23a could cut off such access.

In 2020, another giant iceberg, A68, stirred fears that it would collide with South Georgia, crushing marine life on the sea floor and cutting off food access. Such a catastrophe was ultimately averted when the iceberg broke up into smaller chunks — a possible end game for A23a as well.

But "an iceberg of this scale has the potential to survive for quite a long time in the Southern Ocean, even though it's much warmer, and it could make its way farther north up toward South Africa where it can disrupt shipping," said Marsh. 

Javier Milei, a far-right libertarian who's been compared to former President Donald Trump, was elected Argentina's new president Sunday night to lead the country for the next four years.

Milei, who famously carried a chainsaw to campaign events and called himself "King of the Jungle," is a former frontman of a Rolling Stones cover band and television pundit. In 2021, he was elected to Argentina's congress.

His campaign focused on an economic overhaul that involved cutting spending and closing Argentina's central bank and replacing it with U.S. currency. Some of his other ideas to address the crisis include charging fees for healthcare, xxxx

The election outcome is likely to make a significant impact on Argentina as the country battles through a historic economic crisis with sky-high inflation and the peso losing half of its value this year.

Milei was running against left-leaning Sergio Massa, who served as the country's economy minister. Both men went into the race on Sunday at a dead heat. Massa conceded before the final votes were tallied.

Milei's brash style and conspiracy theories have drawn comparisons to former President Donald Trump. Days before the election, Milei's party, Freedom Advances, alleged fraud, calling the election rigged. Sebastian Schimmel, of the National Electoral Chamber, dismissed the accusations, saying it was "completely unfounded, as they are not even supported by arguments. Nevertheless, they create an atmosphere that aims to instill mistrust."

Massa, a former mayor, congressman and a presidential cabinet chief, was known as a pragmatist with leaning that swing from the right to the left. During his campaign, he tried to woo voters with promises of tax cuts and his ability to run the government. In July 2022, he was appointment economy minister. Inflation has since soared and the peso plummeted. Today, $1 buys 950 pesos. Before the election, many Argentinians expressed concern over his ability to handle economic matters.

The National Electoral Chamber opened more than 106,000 polling stations throughout the country. Voting was mandatory for anyone 18 to 70 and optional for children age 16 and 17, anyone over 71 and residents living abroad.

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“We needed Webb to find this remarkably distant galaxy and Chandra to find its supermassive black hole,” said Akos Bogdan of the Center for Astrophysics | Harvard & Smithsonian (CfA) who leads a new paper in the journal Nature Astronomy describing these results. “We also took advantage of a cosmic magnifying glass that boosted the amount of light we detected.” This magnifying effect is known as gravitational lensing.

Bogdan and his team found the black hole in a galaxy named UHZ1 in the direction of the galaxy cluster Abell 2744, located 3.5 billion light-years from Earth. Webb data, however, has revealed the galaxy is much more distant than the cluster, at 13.2 billion light-years from Earth, when the universe was only 3% of its current age.

Then over two weeks of observations with Chandra showed the presence of intense, superheated, X-ray emitting gas in this galaxy – a trademark for a growing supermassive black hole. The light from the galaxy and the X-rays from gas around its supermassive black hole are magnified by about a factor of four by intervening matter in Abell 2744 (due to gravitational lensing), enhancing the infrared signal detected by Webb and allowing Chandra to detect the faint X-ray source.

This discovery is important for understanding how some supermassive black holes can reach colossal masses soon after the big bang. Do they form directly from the collapse of massive clouds of gas, creating black holes weighing between about 10,000 and 100,000 Suns? Or do they come from explosions of the first stars that create black holes weighing only between about 10 and 100 Suns?

“There are physical limits on how quickly black holes can grow once they’ve formed, but ones that are born more massive have a head start. It’s like planting a sapling, which takes less time to grow into a full-size tree than if you started with only a seed”, said Andy Goulding of Princeton University. Goulding is a co-author of the Nature Astronomy paper and lead author of a new paper in The Astrophysical Journal Letters that reports the galaxy’s distance and mass using a spectrum from Webb.

Bogdan’s team has found strong evidence that the newly discovered black hole was born massive. Its mass is estimated to fall between 10 and 100 million Suns, based on the brightness and energy of the X-rays. This mass range is similar to that of all the stars in the galaxy where it lives, which is in stark contrast to black holes in the centers of galaxies in the nearby universe that usually contain only about a tenth of a percent of the mass of their host galaxy’s stars.

The large mass of the black hole at a young age, plus the amount of X-rays it produces and the brightness of the galaxy detected by Webb, all agree with theoretical predictions in 2017 by co-author Priyamvada Natarajan of Yale University for an “Outsize Black Hole” that directly formed from the collapse of a huge cloud of gas.

“We think that this is the first detection of an ‘Outsize Black Hole’ and the best evidence yet obtained that some black holes form from massive clouds of gas,” said Natarajan. “For the first time we are seeing a brief stage where a supermassive black hole weighs about as much as the stars in its galaxy, before it falls behind.”

The researchers plan to use this and other results pouring in from Webb and those combining data from other telescopes to fill out a larger picture of the early universe.

NASA’s Hubble Space Telescope previously showed that light from distant galaxies is highly magnified by matter in the intervening galaxy cluster, providing part of the motivation for the Webb and Chandra observations described here.

The paper describing the results by Bogdan’s team appears in Nature Astronomy, and a preprint is available online.

The Webb data used in both papers is part of a survey called the Ultradeep Nirspec and nirCam ObserVations before the Epoch of Reionization (UNCOVER). The paper led by UNCOVER team member Andy Goulding appears in the Astrophysical Journal Letters. The co-authors include other UNCOVER team members, plus Bogdan and Natarajan. A detailed interpretation paper that compares observed properties of UHZ1 with theoretical models for Outsize Black Hole Galaxies is forthcoming.

NASA’s Marshall Space Flight Center manages the Chandra program. The Smithsonian Astrophysical Observatory’s Chandra X-ray Center controls science operations from Cambridge, Massachusetts, and flight operations from Burlington, Massachusetts.

The James Webb Space Telescope is the world’s premier space science observatory. Webb is solving mysteries in our solar system, looking beyond to distant worlds around other stars, and probing the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA (European Space Agency) and the Canadian Space Agency.

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