Tokamak experiments exceed plasma density limit, offering new approach to nuclear fusion ignition

Good news! This could be a breakthrough! Are we close to reaching a burning plasma or the sun on Earth?

"Researchers working on China's fully superconducting Experimental Advanced Superconducting Tokamak (EAST) have experimentally accessed a theorized "density-free regime" for fusion plasmas, achieving stable operation at densities well beyond conventional limits. ...

By realizing a novel high-density operating scheme on EAST, the team demonstrated that plasma density, long constrained by empirical limits in tokamak operation, can be substantially extended without triggering disruptive instabilities. ...

For deuterium-tritium fusion reactions, plasmas must be heated to an optimal temperature of around 13 keV (150 million kelvin). Under these conditions, thermonuclear power scales with the square of fuel density.

However, in conventional tokamak operation, plasma density has long been restricted by an empirical upper limit. Exceeding this limit often leads to instabilities that disrupt plasma confinement and endanger tokamak operation, posing a major challenge to improving fusion performance.

The recent development of the plasma–wall self organization (PWSO) theory provides a novel perspective on understanding the disruptive density limit.  ...The theory predicts that a new density-free regime could be accessed by achieving a delicate balance between the plasma and the metallic walls of the device, which are dominated by physical sputtering. ..."

"... While long-term international fusion research has indicated that the physical processes triggering the density limit occur at the plasma-wall boundary region, the underlying mechanisms have remained unclear.

In this study, the Chinese research team developed a self-organized plasma-wall interaction theoretical model. Through this model, they identified the critical role of radiation instability induced by boundary impurities in triggering the density limit, thereby elucidating the underlying mechanism.

Building on this theoretical insight, researchers experimentally controlled the plasma to exceed the density limit and successfully guided it into a new "density-free zone."

These results mark the first experimental confirmation of such a zone in tokamaks. ..."

From the abstract:

"High plasma density operation is crucial for a tokamak to achieve energy breakeven and burning plasma. However, there is often an empirical upper limit of electron density in tokamak operation, namely, the Greenwald density limit ng

, above which tokamaks generally disrupt.

Achieving high-density operation above the density limit has been a long-standing challenge in magnetic confinement fusion research.

Here, we report experimental results on the Experimental Advanced Superconducting Tokamak (EAST) achieving line-averaged electron density in the range of (1.3 to 1.65) ng, significantly above the typical EAST operational range of (0.8 to 1.0) ng. This is performed with electron cyclotron resonance heating (ECRH)–assisted ohmic start-up and sufficiently high initial neutral density.

These experiments are shown to operate in the density-free regime first predicted by a recent plasma-wall self-organization theory. These results suggest a promising scheme for substantially increasing the density limit in tokamaks, a critical advancement toward achieving burning plasma."

Tokamak experiments exceed plasma density limit, offering new approach to fusion ignition

China's "artificial sun" Experiment Finds Way to Break Fusion Plasma Density Limit (original news release)

Accessing the density-free regime with ECRH-assisted ohmic start-up on EAST (open access)

Electron-positron pair-plasma jets like from black holes and neutron stars are now generated at CERN

Amazing stuff!

"... These relativistic jets, as they’re called, are thought to contain a plasma made of electrons and their antimatter equivalent, positrons. ..."

"... That experiment generated extremely high yields of quasi-neutral electron-positron pair beams using more than 100 billion protons from the SPS accelerator. Each proton carries a kinetic energy that is 440 times larger than its resting energy. Because of such large momentum, when the proton smashes an atom, it has sufficient energy to release its internal constituents—quarks and gluons—which then immediately recombine to produce a shower that ultimately decays into electrons and positrons.

In other words, the beam they generated in the lab had enough particles to start behaving like a true astrophysical plasma. ..."

"... Relativistic beams of electron–positron pairs can be created in several ways at different types of laboratories, including high-power laser facilities. However, none of the existing ways can produce the number of electron–positron pairs that is required to sustain a plasma – a state of matter in which the constituent particles are very loosely connected. Without sustaining the plasma, researchers cannot investigate how these analogues of black hole jets change as they move through a laboratory equivalent of the interstellar medium. This investigation is key to explaining observations from ground- and space-based telescopes. ..."

From the abstract:

"Relativistic electron-positron plasmas are ubiquitous in extreme astrophysical environments such as black-hole and neutron-star magnetospheres, where accretion-powered jets and pulsar winds are expected to be enriched with electron-positron pairs. Their role in the dynamics of such environments is in many cases believed to be fundamental, but their behavior differs significantly from typical electron-ion plasmas due to the matter-antimatter symmetry of the charged components. So far, our experimental inability to produce large yields of positrons in quasi-neutral beams has restricted the understanding of electron-positron pair plasmas to simple numerical and analytical studies, which are rather limited. We present the first experimental results confirming the generation of high-density, quasi-neutral, relativistic electron-positron pair beams using the 440 GeV/c beam at CERN’s Super Proton Synchrotron (SPS) accelerator. Monte Carlo simulations agree well with the experimental data and show that the characteristic scales necessary for collective plasma behavior, such as the Debye length and the collisionless skin depth, are exceeded by the measured size of the produced pair beams. Our work opens up the possibility of directly probing the microphysics of pair plasmas beyond quasi-linear evolution into regimes that are challenging to simulate or measure via astronomical observations."

Plasma fireballs from black holes are now being made here on Earth Supermassive black holes have been known to belch gigantic beams of plasma into space – and now scientists have managed to recreate these fireballs in a lab at CERN.

Bringing black hole jets down to Earth The Fireball collaboration has used CERN’s HiRadMat facility to produce an analogue of the jets of matter and antimatter that stream out of some black holes and neutron stars

Pair plasmas found in deep space can now be generated in the lab An international team of scientists has developed a novel way to experimentally produce plasma ‘fireballs’ on Earth.

Laboratory realization of relativistic pair-plasma beams (open access)

HOW IT WORKS: A proton (far left) from the Super Proton Synchrotron (SPS) accelerator at CERN impinges on carbon nuclei (small gray spheres). This produces a shower of various elementary particles, including a large number of neutral pions (orange spheres). As the unstable neutral pions decay, they emit two high-energy gamma rays (yellow squiggly arrows). These gamma rays then interact with the electric field of Tantalum nuclei (large gray spheres), generating electron and positron pairs and resulting in the novel electron-positron fireball plasma. Because of these cascade effects, a single proton can generate many electrons and positrons, making this process of pair plasma production extremely efficient.

Fig. 1: Experimental setup.

Lab builds its first nuclear fusion stellarator in 50 years and opens the door for research into new plasma physics

Good news! The faster we succeed with realizing the potential of nuclear fusion, the fast we can bury the greatest scam of our time, the Global Warming hoax and Climate Change religion.

"For the first time, scientists have built a fusion experiment using permanent magnets, a technique that could show a simple way to build future devices for less cost and allow researchers to test new concepts for future fusion power plants. ...

a new type of stellarator, a twisty machine that confines plasma, the electrically charged fourth state of matter, to harness the fusion process that powers the sun and stars and potentially generate clean electricity.

"Using permanent magnets is a completely new way to design stellarators," ... the device, known as MUSE. "This technique allows us to test new plasma confinement ideas quickly and build new devices easily."

Stellarators typically rely on complicated electromagnets that have complex shapes and create their magnetic fields through the flow of electricity. Those electromagnets must be built precisely with very little room for error, increasing their cost. ..."

From the abstract:

"This paper documents the design and construction of MUSE, the world's first permanent magnet (PM) stellarator and the first quasi-axisymmetric experiment. The purpose of MUSE is to develop and assess a new way of building optimised stellarators that uses simple planar coils PMs. Our PM optimisation algorithm consists of initialising a geometry to pack dipoles densely, running the FAMUS code to minimise surface field error subject to PM constraints and applying discrete jumps to reach a physically realisable solution. FAMUS treats the PM system as a set of ideal point dipoles. From there we construct finite-volume magnet towers to be housed in 3D-printed PM holders. We describe the design of the PM holders, which were validated by laser metrology. We analyse the effects of finite permeability, sensitivity to perturbations and magnetostatic forces. An exact analytic formula for the magnetic field from a finite-volume PM tower is presented to compute PM–PM forces and stress on the PM holder. Stellarator construction is complete and experiments are underway."

A return to roots: Lab builds its first stellarator in 50 years and opens the door for research into new plasma physics

A return to roots: PPPL builds its first stellarator in decades and opens the door for research into new plasma physics (original news release)

Design and construction of the MUSE permanent magnet stellarator (open access)

A photo of MUSE, the first stellarator built at PPPL in 50 years and the first ever to use permanent magnets

At left: Some of the permanent magnets that make MUSE’s innovative concept possible. At right: A close-up of MUSE's 3D-printed shell.

Super hot plasma made easy with stabilising fibres

Recommendable!

Riesiges Potenzial: Forschende erzeugen erstmals abgekoppeltes Plasma

Gute Nachrichten! Wann werden wir endlich Energie von Kernfusion realisieren!

Dann würden wir z.B. nicht mehr unsere Zeit und Ressourcen mit dem Global Warming hoax and Climate Change religion verschwenden!

Riesiges Potenzial: Forschende erzeugen erstmals abgekoppeltes Plasma - ingenieur.de Forschende der Fachhochschule Aachen haben erstmals ein abgekoppeltes Plasma erzeugt. Bisher war die Erzeugung der Plasmen immer an eine Strahlenquelle gebunden – durch die Abkopplung ergeben sich nach Angaben des Forschungsteams ganz neue Nutzungsszenarien, eventuell sogar für die Fusionstechnik, aber auch für Industrieöfen oder Sicherheitskontrollen am Flughafen.

FH-Forscher erzeugen abgekoppeltes Plasma Technologie mit „riesigem Anwendungsfeld“ - bis hin zur Fusionstechnologie

Nuclear fusion researchers spot strange, high-energy behavior in burning plasma

Nuclear fusion is what I call solar power! 😊

"... Researchers recently took an important step towards this goal with the achievement of a self-heating “burning plasma,” and now a closer inspection of that plasma has revealed strange, unexplained behavior of ions within it. ...
New analysis of this burning plasma has now shown it behaves in an unexpected way, with the ions inside it shown to have higher energy than what the models had projected. ..."

"Researchers at Lawrence Livermore National Laboratory (LLNL) have discovered that ions behave differently in fusion reactions than previously expected, thus providing important insights for the future design of a laser­–fusion energy source. ...
The work shows that neutron energy measurements on the high-yield burning and igniting inertial confinement fusion experiments (ICF) showed that the average neutron energy produced is higher than expected for a deuterium-tritium (D-T) plasma that is in thermal equilibrium. ... 

While researchers don’t have a clear understanding of what is driving this observation, it is one of the most direct measurements of the ions undergoing fusion and is not captured by the simulations that are used to understand how to improve ICF implosions and deliver on the Lab’s mission generating a robust and reliable ignition platform. ..."

From the abstract:

"At the National Ignition Facility, inertial confinement fusion experiments aim to burn and ignite a hydrogen plasma to generate a net source of energy through the fusion of deuterium and tritium ions. The energy deposited by α-particles released from the deuterium–tritium fusion reaction plays the central role in heating the fuel to achieve a sustained thermonuclear burn. In the hydrodynamic picture, α-heating increases the temperature of the plasma, leading to increased reactivity because the mean ion kinetic energy increases. Therefore, the ion temperature is related to the mean ion kinetic energy. Here we use the moments of the neutron spectrum to study the relationship between the ion temperature (measured by the variance in the neutron kinetic energy spectrum) and the ion mean kinetic energy (measured by the shift in the mean neutron energy). We observe a departure from the relationship expected for plasmas where the ion relative kinetic energy distribution is Maxwell–Boltzmann, when the plasma begins to burn. Understanding the cause of this departure from hydrodynamic behaviour could be important for achieving robust and reproducible ignition."

Fusion researchers spot strange, high-energy behavior in burning plasma

LLNL researchers observe that ions behave differently in fusion reactions

Evidence for suprathermal ion distribution in burning plasmas (no public access)

Giant lasers help re-create supernovas’ explosive, mysterious physics

Amazing stuff!

"“The iron in our blood comes from supernovae,” ... The laboratory explosions happen in an instant and are tiny, just centimeters across. For example .... the equivalent of 15 minutes in the life of a real supernova can take just 10 billionths of a second. And a section of a stellar explosion larger than the diameter of Earth can be shrunk down to 100 micrometers. ... For that, you need a really big laser, which can be found in only a few places in the world, such as NIF, the National Ignition Facility at Lawrence Livermore, and the OMEGA Laser Facility at the University of Rochester in New York.

At both places, one laser is split into many beams. The biggest laser in the world, at NIF, has 192 beams. Each of those beams is amplified to increase its energy exponentially. Then, some or all of those beams are trained on a small, carefully designed target. NIF’s laser can deliver more than 500 trillion watts of power for a brief instant, momentarily outstripping the total power usage in the United States by a factor of a thousand. "

Giant lasers help re-create supernovas’ explosive, mysterious physics | Science News Pocket-sized blasts in the lab reveal details of massive stellar explosions

Plasma Jets May One Day Propel Aircraft

Are we about to see a revolution in aircraft technology more than 120 years after the Wright brothers?

"Now researchers have created a prototype thruster capable of generating plasma jets with propulsive forces comparable to those from conventional jet engines, using only air and electricity.
An air compressor forces high-pressure air at a rate of 30 liters per minute into an ionization chamber in the device, which uses microwaves to convert this air stream into a plasma jet blasted out of a quartz tube. Plasma temperatures could exceed 1,000 °C. ... The scientists estimated the jet pressure from their device reached 2,400 newtons per square meter, comparable to that from a commercial airplane jet engine. ... All in all, “I think that within five years, one could use a scaled-up plasma engine to power small pilotless airplanes or heavy-duty drones to carry cargo for shipping,” ..."

One of the interviewed scientists working on this is: "Jau Tang, a physicist at Wuhan University [this university is located in Wuhan city] in China and senior author of a new study describing the work". What a coincidence!

Plasma Jets May One Day Propel Aircraft - IEEE Spectrum Plasma thrusters could help jet planes fly without fossil fuels

Here is the underlying research paper: Jet propulsion by microwave air plasma in the atmosphere