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#1 2023-11-27 11:24:56

tahanson43206
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Registered: 2018-04-27
Posts: 19,263

Stellarator vs Tokamak vs Laser ignition - Fusion competition

This topic is offered for those of our members who would like to help to build a repository of links and text about fusion research.

The first post in this new topic will be a report on the resurgence of the Stellarator.

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#2 2023-11-27 11:28:12

tahanson43206
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Registered: 2018-04-27
Posts: 19,263

Re: Stellarator vs Tokamak vs Laser ignition - Fusion competition

The article at the link below reports on the resurgence of the Stellarator in competition with Tokamak and the Laser Ignition concept.

https://www.weforum.org/agenda/2023/06/ … on-energy/

The article includes a bit of history.  I had not realized that the Stellarator had preceded the Tokamak.

I attended a lecture by Lyman Spitzer years ago, when he was visiting his home town.

Lyman Spitzer Jr. was born on June 26, 1914 in Toledo, Ohio.

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#3 2023-12-01 15:55:14

tahanson43206
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Re: Stellarator vs Tokamak vs Laser ignition - Fusion competition

The article at the link below is about a traditional Tokamak under construction in Japan ....

https://www.yahoo.com/news/japan-debuts … 00642.html

Gizmodo
Japan Debuts Six-Story Experimental Fusion Reactor
Isaac Schultz
Fri, December 1, 2023 at 3:15 PM EST·2 min read

The completed reactor. << image

The biggest experimental nuclear fusion reactor in operation was inaugurated north of Tokyo today, as scientists continue to plug away at making nuclear fusion a viable source of the world’s energy.

The reactor—JT-60SA—is a tokamak, a doughnut-shaped reactor that can heat plasma to 360 million degrees Fahrenheit (200 million degrees Celsius). The reactor fired up for the first time in October; at the time, researchers affiliated with the project estimated that it will take two years for the reactor to produce the plasmas necessary for experiments, according to the publication Science.

Read more

Nuclear fusion can be done in different ways, but it is regardless a much cleaner process than nuclear fission. Fusion is a thermonuclear reaction that causes two light atomic nuclei to fuse into a heavier nucleus, producing huge amounts of energy in the process. Nuclear fission happens by splitting a large atom into smaller particles; it produces less energy than fusion reactions and produces radioactive material as a waste product, while fusion does not.

The interior of the JET tokamak, which achieved a record reaction in 1997, a result doubled by JET last year.

Last year, scientists at Lawrence Livermore National Laboratory achieved net energy gain in a fusion reaction, meaning the reaction produced more energy (3 megajoules) than it took to power the reaction in the first place (2 megajoules). It was a significant achievement, but required a far more tremendous amount of energy to power (300 megajoules); in other words, despite the sensational flurry that every bit of progress on fusion causes, there’s a long road ahead.

The fusion experiments that take place in JT-60SA will inform the science that will eventually happen in ITER, a reactor that can hold six times the volume of its Japanese partner. However, JT-60SA will not use tritium—a rare isotope of hydrogen—in its reactions, while ITER plans to start using it in 2035, according to Science.

Nevertheless, JT-60SA will “bring us closer to fusion energy,” Sam Davis, the reactor’s deputy project leader, said in the inauguration. “It’s the result of a collaboration between more than 500 scientists and engineers and more than 70 companies throughout Europe and Japan.”

While large collaborations are working on large tokamaks and stellarators, projects like the MIT-CFS collaboration’s SPARC experiment are building smaller reactors that make use of high-temperature superconducting magnets. SPARC is expected to be completed in 2025, the same year ITER’s first plasma is (currently) expected.

The running joke about scalable nuclear fusion is that it is always just over the horizon—maybe 30, 50 years from now. This timeline is fanciful, but it can never be a reality without work being done towards that end now. So fingers crossed and hats off to you, JT-60SA. Make your run be a fruitful one.

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#4 2023-12-01 16:25:55

Mars_B4_Moon
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Re: Stellarator vs Tokamak vs Laser ignition - Fusion competition

The Chinese are also invested, China has a nuclear fusion reactor called EAST and there is also a report of the China Fusion Engineering Test Reactor.

https://phys.org/news/2020-12-china-nuc … l-sun.html

https://english.cas.cn/newsroom/news/20 … 9388.shtml

Culturally it might become mainstream among the Green-Left with guys like Oliver Stone making 'Nuclear Now' movies and films, the latest movie is based on the book A Bright Future: How Some Countries Have Solved Climate Change and the Rest Can Follow. The movie accuses the anti-nuclear movement of equating nuclear power with nuclear weapons and thus creating a primal fear against this form of energy.  I'm not sure how they will get those renewables, emissions reduction target without some 'Fusion' reactor happening.

There are also hybrid fission-fusion systems discussed in other newmars topics

Last edited by Mars_B4_Moon (2023-12-01 16:27:44)

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#5 2024-08-11 11:47:59

tahanson43206
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Re: Stellarator vs Tokamak vs Laser ignition - Fusion competition

This post is about manufacture of the pellets that are used by the US Inertial Fusion facility for testing.

https://interestingengineering.com/ener … 10.08.24_2

World’s first fusion ignition breakthrough: US firm wins esteemed award
Without the 4Pi system, it would have been challenging to fabricate the perfect capsule for successful nuclear fusion ignition.

Updated: Aug 10, 2024 05:13 AM EST
Rupendra Brahambhatt

World&#8217;s first fusion ignition breakthrough: US firm wins esteemed award
The General Atomics team with their 4Pi system.

Source: General Atomics

The R&D 100 awards, hailed as the “Nobel Prize” for engineers and innovators, recently recognized General Atomics as the R&D Team of the Year. They were selected because of their 4Pi system that contributed to the world’s first successful controlled fusion ignition. 

Notably, the National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory in the US achieved the first controlled fusion ignition using the 4Pi system.

This was the first time when scientists were able to produce more energy from fusion than the energy they used to initiate the fusion reaction. The results of this historic experiment proved that it was practically possible to produce clean energy from nuclear fusion on Earth.

“The device, known as the 4Pi Integrated Metrology System, is an unprecedented technology that has been pivotal in helping to achieve and repeat fusion ignition at the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL),” the General Atomics team wrote in a press release.

However, in order to understand the workings of the 4Pi system, one first needs to understand nuclear fusion and the details of the 2022 controlled fusion ignition experiment.

The first successful nuclear fusion ignition

When two small atomic nuclei fuse together and form a larger nucleus, they release enormous amounts of energy and heat. This process is called nuclear fusion. It occurs in stars, including our Sun, where hydrogen atoms combine to form helium. The energy and heat released during this reaction is what powers the Sun and stars.

Since the 1950s, scientists across the globe have been trying to make nuclear fusion practical on Earth to generate abundant clean energy. It took them more than seventy years to achieve controlled fusion ignition, the first step towards realizing fusion as a viable clean energy source.

During the 2022 fusion experiment, the NIF team employed the inertial confinement fusion (ICF) method. They placed a tiny pellet filled with deuterium and tritium fuel in a capsule. Next, they used 192 powerful lasers to fire at the capsule from all directions.

The lasers generated intense heat and pressure, compressing the fuel to the extreme conditions needed for nuclear fusion to occur. The energy released from this fusion reaction exceeded the energy input, making ignition possible for the first time.

According to the General Atomics team, their 4Pi system played a critical role in the success of the 2022 ignition experiment. It was used as a diagnostic tool to measure the conditions within the fusion capsule.

Role of 4Pi in nuclear fusion ignition

The fusion capsule is generally only 2 mm in diameter, and for a successful ignition, it should be free from any defects. For instance, it is made with extreme precision, with measurements smaller than one-millionth of a meter.

“The fuel capsules need to be as perfect as possible because the tiniest defects could affect the behavior of the fuel when the target is compressed—meaning abnormalities smaller than 1/100th the diameter of a human hair could stifle ignition,” the General Atomics team explained.

The 4Pi system allowed scientists to keep a check on the quality and the fusion capsule. For instance, during the capsule fabrication process, it automatically screens the capsules, detects defects, and makes precise improvements.

General Atomics’ 4Pi system integrates up to eight instruments within a unified coordinate system, including robotics, automation, batch evaluation, and machine learning technologies. This approach eliminates measurement errors that can arise from manually transferring a target between instruments. Consequently, it enables the identification of the highest-quality targets from each production batch.

RECOMMENDED ARTICLES

Series of successful testing

Since December 2022, scientists have conducted successful fusion ignition five times, and the 4Pi system has been an integral part of these experiments. Its importance is evident from the fact that the R&D awards jury selected 4Pi out of 100s of other innovations submitted by researchers from 16 different countries.

The team behind the 4Pi system is excited after winning the R&D award, and they look forward to further advancing their technology.

“I am confident the 4Pi system will continue to play a significant role in assisting scientists to understand the fundamental principles to routinely and robustly produce fusion-ignition conditions,” Mike Farrell, vice president of Inertial Fusion Technologies at General Atomics, said.

ABOUT THE EDITOR
Rupendra Brahambhatt Rupendra Brahambhatt is an experienced writer, researcher, journalist, and filmmaker. With a B.Sc (Hons.) in Science and PGJMC in Mass Communications, he has been actively&nbsp;working with&nbsp;some of the most innovative brands, news agencies, digital magazines,&nbsp;documentary filmmakers, and nonprofits from different parts of the globe. As an author, he works&nbsp;with a vision to bring forward the right information and encourage a constructive mindset among the masses.

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#6 2024-08-25 06:34:11

tahanson43206
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Re: Stellarator vs Tokamak vs Laser ignition - Fusion competition

This topic is about competition between the three major concepts for human managed fusion...

https://www.yahoo.com/lifestyle/chinas- … 00935.html

In this case, the progress reported is for a Tokamak design in China...

The EAST (Experimental Advanced Superconducting Tokamak) nuclear fusion reactor maintained a temperature of 158 million degrees Fahrenheit for 1,056 seconds. The achievement brings scientists a small yet significant step closer to the creation of a source of near-unlimited clean energy.

There's not much detail in the short video ...

Here's a bit more that Google found:

People also ask
What is the record for the tokamak reactor?
What is the longest running tokamak?
[ Record] China's Experimental Advanced Superconducting Tokamak (EAST), a nuclear fusion reactor research facility, sustained plasma at 70 million degrees Celsius for as long as 1,056 seconds (17 minutes, 36 seconds), achieving the new world record for sustained high temperatures (fusion energy however requires i.a. ...

Timeline of nuclear fusion - Wikipedia

Wikipedia
https://en.wikipedia.org › wiki › Timeline_of_nuclear_f...
Search for: What is the longest running tokamak?

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#7 2024-08-25 06:36:57

tahanson43206
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Registered: 2018-04-27
Posts: 19,263

Re: Stellarator vs Tokamak vs Laser ignition - Fusion competition

I asked Google for the previous fusion reactor record and it came up with this UK example...

The reactor's previous record was a reaction lasting for 5 seconds in 2021, producing 59 megajoules of heat energy. But in its final tests in late 2023, it surpassed this by sustaining a reaction for 5.2 seconds while also reaching 69 megajoules of output, using just 0.2 milligrams of fuel.Feb 8, 2024

UK nuclear fusion reactor sets new world record for energy ...

It is possible the report of energy production by the UK reactor still stands, because the Chinese achievement did not report energy produced in the limited information I've found so far.

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#8 2024-08-25 06:50:24

tahanson43206
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Posts: 19,263

Re: Stellarator vs Tokamak vs Laser ignition - Fusion competition

The article at the link below is on the longer side. It contains details about development of a new way of measuring performance of a fusion reactor bv taking multiple readings...

https://www.pppl.gov/news/2024/fusion-r … 2DAparicio.

The article describes the discoveries made by changing from walls of carbon to walls of tungsten.

The carbon walls absorbed tritium, which is a needed output of the reactor.

Tungsten walls do not absorb tritium at the same rate, but on the other hand, unlike carbon, tungsten atoms floating out into the plasma cause the temperature to drop by absorbing energy.

Interesting problem.

The article is dated:

Rachel Kremen
May 6, 2024
Researchers at the U.S. Department of Energy(Link is external)’s (DOE) Princeton Plasma Physics Laboratory (PPPL) measured a new record for a fusion(Link is external) device internally clad in tungsten, the element that could be the best fit for the commercial-scale machines required to make fusion a viable energy source for the world.

The device sustained a hot fusion plasma(Link is external) of approximately 50 million degrees Celsius for a record six minutes with 1.15 gigajoules of power injected, 15% more energy and twice the density than before. The plasma will need to be both hot and dense to generate reliable power for the grid.

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#9 2024-09-19 07:18:21

tahanson43206
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Re: Stellarator vs Tokamak vs Laser ignition - Fusion competition

This article from CNN reports on the competition between the US and China....
https://www.cnn.com/2024/09/19/climate/ … index.html

It appears that funding in China may be greater than in the US ....

The article reports on recent achievements....

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Close this content
CNN
The US led on nuclear fusion for decades. Now China is in position to win the race
Angela Dewan and Ella Nilsen, CNN
Thu, September 19, 2024 at 4:00 AM EDT·8 min read
9

The bustling city of Shanghai marks national celebrations with world-famous light shows, illuminating its skyscrapers with dazzling colors, like beacons of Chinese innovation.

It is here that scientists and engineers work around the clock to pursue the next big thing in global tech, from 6G internet and advanced AI to next-generation robotics. It’s also here, on an unassuming downtown street, a small start-up called Energy Singularity is working on something extraordinary: nuclear fusion energy.

US companies and industry experts are worried America is losing its decades-long lead in the race to master this near-limitless form of clean energy, as new fusion companies sprout across China, and Beijing outspends DC.

Nuclear fusion, the process that powers the sun and other stars, is painstakingly finicky to replicate on Earth. Many countries have achieved fusion reactions, but sustaining them for long enough to use in the real world remains elusive.

Mastering fusion is an enticing prospect that promises wealth and global influence to whichever country tames it first.

The city of Shanghai by night. - Lam Yik Fei/The New York Times/Redux
The city of Shanghai by night. - Lam Yik Fei/The New York Times/Redux
The prize of this energy is its sheer efficiency. A controlled fusion reaction releases around four million times more energy than burning coal, oil or gas, and four times more than fission, the kind of nuclear energy used today. It won’t be developed in time to fight climate change in this crucial decade, but it could be the solution to future warming.

The Chinese government is pouring money into the venture, putting an estimated $1 billion to $1.5 billion annually into fusion, according to Jean Paul Allain, who leads the US Energy Department’s Office of Fusion Energy Sciences. In comparison, the Biden administration has spent around $800 million a year.

“To me, what’s more important than the number, it’s actually how fast they’re doing this,” Allain told CNN.

Private businesses in both countries are optimistic, saying they can get fusion power on the grid by the mid-2030s, despite the enormous technical challenges that remain.

The US was among the world’s first to move on the futuristic gambit, working on fusion research in earnest since the early 1950s. China’s foray into fusion came later that decade. More recently, its pace has ratcheted up: Since 2015, China’s fusion patents have surged, and it now has more than any other country, according to industry data published by Nikkei.

Energy Singularity, the start-up in Shanghai, is just one example of China’s warp speed.

It built its own tokamak in the three years since it was established, faster than any comparable reactor has ever been built. A tokamak is a highly complex cylindrical or donut-shaped machine that heats hydrogen to extreme temperatures, forming a soup-like plasma in which the nuclear fusion reaction occurs.

Plasma confined in Energy Singularity's tokamak during an experiment. - Energy Singularity
Plasma confined in Energy Singularity's tokamak during an experiment. - Energy Singularity
For a fledgling company working on one of the world’s most difficult physics puzzles, Energy Singularity is incredibly optimistic. It has reason to be: It has received more than $112 million in private investment and it has also achieved a world first — its current tokamak is the only one to have used advanced magnets in a plasma experiment.

Known as high-temperature superconductors, the magnets are stronger than the copper ones used in older tokamaks. According to MIT scientists researching the same technology, they allow for smaller tokamaks that can generate as much fusion energy as larger ones, and they can better confine plasma.

The company is planning to build a second-generation tokamak to prove its methods are commercially viable by 2027, and it expects a third-gen device that can feed power to the grid before 2035, the company said.

In contrast, the tokamaks in the US are aging, said Andrew Holland, CEO of the Washington, DC-based Fusion Industry Association. As a result, the US relies on its allies’ machines in Japan, Europe and the UK to further its research.

Holland pointed to a new $570 million fusion research park in eastern China under construction, called CRAFT, on track to be completed next year.

“We don’t have anything like that,” he told CNN. “The Princeton Platinum Physics Laboratory has been upgrading its tokamak for 10 years now. The other operating tokamak in the United States, the DIII-D, is a 30-year-old machine. There’s no modern fusion facilities at American national labs.”

There’s a growing unease in the US industry that China is beating America at its own game. Some of the next-generation tokamaks China has built, or plans to, are essentially “copies” of US designs and use components that resemble those made in America, Holland said.

A staff member welds parts together at the CRAFT fusion research park in in Hefei, eastern China, in  September 2023. The BEST tokamak will be built next to CRAFT. - Xinhua/Shutterstock
A staff member welds parts together at the CRAFT fusion research park in in Hefei, eastern China, in September 2023. The BEST tokamak will be built next to CRAFT. - Xinhua/Shutterstock
China’s state-funded BEST tokamak, which is expected to be completed in 2027, is a copy of one designed by Commonwealth Fusion Systems, Holland said, a company in Massachusetts working with MIT. The two designs feature the same kind of advanced magnets Energy Singularity is using.

Another machine being built by a private Chinese company looks very similar to a tokamak designed by the US company Helion, Holland said.

There is “a long history” of China copying American tech, he added.›

“They’re fast followers and then take the lead by dominating the supply chain,” Holland said, using solar panel technology as an example. “We’re aware of this and want to make sure that’s not the way it goes forward.”

CNN did not receive a reply from China’s National Energy Administration when asked whether state-funded fusion research had copied or been inspired by US designs.

Lasers vs. tokamaks
Nuclear fusion is a highly complex process that involves forcing together two nuclei that would normally repel. One way to do that is to turn up temperatures in a tokamak to the tune of 150 million degrees Celsius, 10 times that of the sun’s core.

When they bind, the nuclei let off a large amount of energy as heat, which can then be used to turn turbines and generate power.

The US has been a fusion leader for decades; it was the first nation to apply fusion energy in the real world — in a hydrogen bomb.

In the early 1950s, the US military tested a series of nuclear weapons in the Pacific Ocean that were “boosted” by gases that created a fusion reaction, resulting in an explosion 700 times the power of Hiroshima blast.

Sustaining nuclear fusion for long periods is much more challenging, and while China races ahead with its tokamaks, the US is finding an edge in other technology: lasers.

In late 2022, scientists at the Lawrence Livermore National Laboratory in California shot nearly 200 lasers at a cylinder holding a fuel capsule the size of a peppercorn, in the world’s first successful experiment to generate a net gain of fusion energy. That means more power came out of the process than was used to heat the capsule (though they didn’t count the energy needed to power the lasers).

A component in the laser system at the Lawrence Livermore National Laboratory, where scientists successfully achieved "ignition" to produce a fusion reaction. - Damien Jemison/Lawrence Livermore National Laboratory
A component in the laser system at the Lawrence Livermore National Laboratory, where scientists successfully achieved "ignition" to produce a fusion reaction. - Damien Jemison/Lawrence Livermore National Laboratory
There are yet more ways to achieve nuclear fusion, and the US is hedging its bets on a variety of technologies.

It’s not impossible that approach could pay off.

“We don’t know exactly which is going to be the best concept, and it may not be one,” said Melanie Windridge, a UK-based plasma physicist and CEO of Fusion Energy Insights, an industry monitoring organization. There may ultimately be several viable approaches for fusion power, she told CNN. “And then it will come down to costs and other factors in the longer term.”

But the tokamak is the best-researched concept, she said.

“Over time, it’s had the most research put into it, so it’s the most advanced in terms of the physics,” said Windridge. “And a lot of the private companies are building on that.”

With the money China is putting into research, the tokamak concept is rapidly evolving. China’s EAST tokamak in Hefei held plasma stable at 70 million degrees Celsius — five times hotter than the core of the sun — for more than 17 minutes, a world record and an objectively astonishing breakthrough.

Mikhail Maslov of the UK Atomic Energy Authority described it as an “important milestone,” adding that running long plasma pulses remains one of the biggest technical challenges to commercializing fusion energy.

While China’s government pours money into fusion, the US has attracted far more private investment. Globally, the private sector has spent $7 billion on fusion in the last three to four years, about 80% of which has been by US companies, the DOE’s Allain said.

“In the US, what you have is that entrepreneurial spirit of being able to really think outside the box and innovate and really address some of these gaps, not just in science, but also in the technology,” he said.

But if the Chinese government continues to invest more than $1 billion a year, that could soon eclipse US spending, even in the private sector.

And if those investments pay off, colorful celebrations in Shanghai will not only be powered by fusion, they will cast China in a whole new light.

For more CNN news and newsletters create an account at CNN.com

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#10 2024-10-05 07:16:23

tahanson43206
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Re: Stellarator vs Tokamak vs Laser ignition - Fusion competition

In another topic, RobertDyck has introduced some interesting ideas about fusion.

This post is inspired by RobertDyck's initiative, and is an attempt to offer glimpses of snippets that might tempt a reader to explore the topic further.

The question posed to Google was "what is the velocity of ions in a tokamak or stellarator"

AI Overview
Learn more…
In a tokamak or stellarator, the velocity of ions typically ranges in the order of kilometers per second (km/s), with the exact value depending on the specific device and plasma conditions, but can reach up to tens of kilometers per second; for reference, the toroidal rotation velocity in a tokamak can be a significant fraction of the ion thermal velocity.
Key points about ion velocity in fusion devices:

    High velocities:
    Due to the extreme temperatures in a fusion plasma, ions move at very high speeds, reaching into the kilometer per second range.

Variation with device:
The exact ion velocity can differ between tokamaks and stellarators, with stellarators generally having slightly lower ion velocities due to their different magnetic field configurations.
Impact of magnetic field:
The strong magnetic fields in these devices confine the ions, influencing their movement and velocity.
Measurement methods:
Special diagnostic techniques like heavy ion beam probes are used to measure the velocity of ions in a plasma.

    A general comparison between tokamak and stellarator plasmas
    Thus, in tokamaks the toroidal rotation velocity can reach a very high value, being a significant fraction of the ion thermal velo...
    ScienceDirect.com

Flow Velocity Measurements Using ChERS in the HSX ...
The intrinsic velocity is found to move primarily in the direction of quasihelical symmetry with a peak velocity ∼20 km/s. ... ord...
Helically Symmetric eXperiment
Magnetic Fusion Confinement with Tokamaks and Stellarators | IAEA
While tokamaks are better at keeping plasmas hot, stellarators are better at keeping them stable. Despite the tokamak's current pr...
International Atomic Energy Agency

    Show all

Show more

A general comparison between tokamak and stellarator ...
ScienceDirect.com
https://www.sciencedirect.com › science › article › pii
by Y Xu · 2016 · Cited by 118 — Thus, in tokamaks the toroidal rotation velocity can reach a very high value, being a significant fraction of the ion thermal velocity. In non-axisymmetric ...
People also ask
What is the speed of particles in a tokamak?
What is the difference between tokamak and stellarator?
How strong is the magnetic field in a tokamak?
What is the physics of a tokamak?
Feedback

Bootstrap current and parallel ion velocity in imperfectly ...
Cambridge University Press & Assessment
https://www.cambridge.org › core › journals › article › b...
by PJ Catto · 2020 · Cited by 3 — In stellarators and tokamaks, the flow velocity of each plasma species along the magnetic field is affected by the cross-field (radial) ...

How do ions and electrons follow directions in a stellarator
Physics Forums
https://www.physicsforums.com › threads › how-do-ion...
Oct 12, 2016 — No, ions and electrons can follow different paths in a stellarator depending on their energy and velocity. The magnetic fields can be adjusted ...

Magnetic Fusion Confinement with Tokamaks and ...
International Atomic Energy Agency
https://www.iaea.org › bulletin › magnetic-fusion-confine...
Scientists use magnetic confinement devices to manipulate plasmas. The most common fusion reactors of that kind are tokamaks and stellarators.
Missing: velocity | Show results with: velocity

Comparison between stellarator and tokamak divertor ...
MPG.PuRe
https://pure.mpg.de › items › file_2139638 › content
PDF
by Y Feng · 2011 · Cited by 106 — Only one point needs to be emphasized here: the background plasma ions flowing along the two divertor legs. (single-null) have opposite toroidal velocities.

Flow-Velocity-Measurements-Using-ChERS-in-the-HSX- ...
HSX - Helically Symmetric eXperiment
https://hsx.wisc.edu › uploads › sites › 2020/07 › F...
PDF
by A Briesemeister · Cited by 16 — This has led to an interest in the effects of 3D magnetic field structures on plasma flow velocity in tokamaks [7] as well as stellarators. Asymmetries in ...
4 pages

Exploring Optimization of the Stellarator over Tokamak ...
NHSJS
https://nhsjs.com › NHSJS Reports
what is the velocity of ions in a tokamak or stellarator from nhsjs.com
by RA Khan — In 2018 the fusion product of the stellarator reached well over 6*1026 Celcius m-3 s at a plasma temperature of just 40 million degrees Celcius ...
Missing: velocity | Show results with: velocity

Tokamak
Wikipedia
https://en.wikipedia.org › wiki › Tokamak
what is the velocity of ions in a tokamak or stellarator from en.wikipedia.org
A tokamak is a device which uses a powerful magnetic field generated by external magnets to confine plasma in the shape of an axially symmetrical torus.
Tokamak Fusion Test Reactor · Spherical tokamak · Stellarator · SPARC (tokamak)

How nuclear fusion works (3) - magnetic confinement ...
YouTube · Improbable Matter
92.4K+ views · 2 years ago
23:55
How nuclear fusion works (3) - magnetic confinement, tokamaks, stellarators · Comments214.
16 key moments in this video

Stellarator and tokamak plasmas – a comparison
MPG.PuRe
https://pure.mpg.de › items › file_2146014 › content
PDF
by P Helander · 2012 · Cited by 221 — The toroidal ro- tation velocity frequently reaches a considerable fraction of the ion thermal speed, vTi, even in the absence of deliberate momentum sources.

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#11 2024-10-05 07:27:42

tahanson43206
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Re: Stellarator vs Tokamak vs Laser ignition - Fusion competition

The idea of RobertDyck (new topic about fusion without vacuum, October 2024) that I find most interesting is the idea of creating zones of concentration.  In his topic, RobertDyck has introduced the possibility that it might be possible to create shock waves in a plasma, as a way of concentrating ions to improve chances of collisions that would yield fusion events.

This post is about the general idea of increasing chances of collisions in ordinary stellarators or tokamaks.

The topic created by RobertDyck includes an image of a linear flow of rocket exhaust that clearly shows shock waves in the flow of gas molecules.

I am picking up on the linear flow and combining it with the existing torus shaped tokamak design, or the slightly more complex stellarator figure 8 path.

Suppose we feed a linear flow into a standard totakak torus?  The probability of a collision that produces a useful result should be increased.

On the ** other ** hand, the momentum of ions in the torus will be disrupted by arriving ions from the linear injector.

The rate at which ions are injected would need to be adjusted so that the momentum of the ions in the torus is not destroyed completely.

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