Pushing the plasma density limit

August 24, 2018 by Paul Rivenberg, Massachusetts Institute of Technology
Seung Gyou Baek and his colleagues performed experiments on the Alcator C-Mod tokamak to demonstrate how microwaves can be used to overcome barriers to steady-state fusion reactor operation. Credit: Paul Rivenberg/PSFC

For decades, researchers have been exploring ways to replicate on Earth the physical process of fusion that occurs naturally in the sun and other stars. Confined by its own strong gravitational field, the sun's burning plasma is a sphere of fusing particles, producing the heat and light that makes life possible on earth. But the path to a creating a commercially viable fusion reactor, which would provide the world with a virtually endless source of clean energy, is filled with challenges.

Researchers have focused on the tokamak, a device that heats and confines turbulent plasma fuel in a donut-shaped chamber long enough to create fusion. Because plasma responds to magnetic fields, the torus is wrapped in magnets, which guide the fusing plasma particles around the toroidal chamber and away from the walls. Tokamaks have been able to sustain these reactions only in short pulses. To be a practical source of energy, they will need to operate in a steady state, around the clock.

Researchers at MIT's Plasma Science and Fusion Center (PSFC) have now demonstrated how microwaves can be used to overcome barriers to steady-state tokamak operation. In experiments performed on MIT's Alcator C-Mod tokamak before it ended operation in September 2016, research scientist Seung Gyou Baek and his colleagues studied a method of driving current to heat the plasma called Lower Hybrid Current Drive (LHCD). The technique generates plasma current by launching microwaves into the tokamak, pushing the electrons in one direction—a prerequisite for steady-state operation.

Furthermore, the strength of the Alcator magnets has allowed researchers to investigate LHCD at a high enough to be relevant for a . The encouraging results of their experiments have been published in Physical Review Letters.

Pioneering LHCD

"The conventional way of running a tokamak uses a central solenoid to drive the current inductively," Baek says, referring to the magnetic coil that fills the center of the torus. "But that inherently restricts the duration of the tokamak pulse, which in turn limits the ability to scale the tokamak into a steady-state power reactor."

Baek and his colleagues believe LHCD is the solution to this problem.

MIT scientists have pioneered LHCD since the 1970s, using a series of "Alcator" tokamaks known for their compact size and high magnetic fields. On Alcator C-Mod, LHCD was found to be efficient for driving currents at low density, demonstrating plasma current could be sustained non-inductively. However, researchers discovered that as they raised the density in these experiments to the higher levels necessary for steady-state operation, the effectiveness of LHCD to generate plasma current disappeared.

This fall-off in effectiveness as density increased was first studied on Alcator C-Mod by research scientist Gregory Wallace.

"He measured the fall-off to be much faster than expected, which was not predicted by theory," Baek explains. "The last decade people have been trying to understand this, because unless this problem is solved you can't really use this in a reactor."

Researchers needed to find a way to boost effectiveness and overcome the LHCD density limit. Finding the answer would require a close examination of how lower hybrid (LH) waves respond to the tokamak environment.

Driving the current

Lower hybrid waves drive plasma current by transferring their momentum and energy to electrons in the plasma.

Head of the PSFC's Physics Theory and Computation Division, senior research scientist Paul Bonoli compares the process to surfing.

"You are on a surf board and you have a wave come by. If you just sit there the wave will kind of go by you," Bonoli says. "But if you start paddling, and you get near the same speed as the wave, the wave picks you up and starts transferring energy to the surf board. Well, if you inject radio waves, like LH waves, that are moving at velocities near the speed of the particles in the plasma, the waves start to give up their energy to these particles."

Temperatures in today's tokamaks—including C-Mod—are not high enough to provide good matching conditions for the wave to transfer all its momentum to the plasma particles on the first pass from the antenna, which launches the waves to the core plasma. Consequently, researchers noticed, the injected microwave travels through the core of the plasma and beyond, eventually interacting multiple times with the edge, where its power dissipates, particularly when the density is high.

Exploring the scrape-off layer

Baek describes this edge as a boundary area outside the main core of the plasma where, in order to control the plasma, researchers can drain—or "scrape-off"—heat, particles, and impurities through a divertor. This edge has turbulence, which, at higher densities, interacts with the injected microwaves, scattering them, and dissipating their energy.

"The scrape-off layer is a very thin region. In the past RF scientists didn't really pay attention to it," Baek says. "Our experiments have shown in the last several years that interaction there can be really important in understanding the problem, and by controlling it properly you can overcome the density limit problem."

Baek credits extensive simulations by Wallace and PSFC research scientist Syun'ichi Shiraiwa for indicating that the scrape-off layer was most likely the location where LH wave power was being lost.

Detailed research on the edge and scrape-off-layer conducted on Alcator C-Mod in the last two decades has documented that raising the total electrical current in the plasma narrows the width of the scrape-off-layer and reduces the level of turbulence there, suggesting that it may reduce or eliminate its deleterious effects on the microwaves.

Motivated by this, PSFC researchers devised an LHCD experiment to push the total current by from 500,000 Amps to 1,400,000 Amps, enabled by C-Mod's high-field tokamak operation. They found that the effectiveness of LCHD to generate plasma current, which had been lost at high density, reappeared. Making the width of the turbulent scrape-off layer very narrow prevents it from dissipating the microwaves, allowing higher densities to be reached beyond the LHCD density limit.

The results from these experiments suggest a path to a steady-state fusion reactor. Baek believes they also provide additional experimental support to proposals by the PSFC to place the LHCD antenna at the high-field (inboard) side of a tokamak, near the central solenoid. Research suggests that placing it in this quiet area, as opposed to the turbulent outer midplane, would minimize destructive wave interactions in the edge, while protecting the antenna and increasing its effectiveness. Principal Research scientist Steven Wukitch is currently pursuing new LHCD research in this area through PSFCs' collaboration with the DIII-D tokamak in San Diego.

Although existing tokamaks with LHCD are not operating at the high densities of C-Mod, Baek feels that the relationship between the current drive and the scrape-off layer could be investigated on any tokamak.

"I hope our recipe for improving LHCD performance will be explored on other machines, and that these results invigorate further research toward steady-state operation," he says.

Explore further: Higher plasma densities, more efficient tokamaks

More information: S. G. Baek et al. Observation of Efficient Lower Hybrid Current Drive at High Density in Diverted Plasmas on the Alcator C-Mod Tokamak, Physical Review Letters (2018). DOI: 10.1103/PhysRevLett.121.055001

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Mark Thomas
2.7 / 5 (7) Aug 24, 2018
raising the total electrical current in the plasma narrows the width of the scrape-off-layer and reduces the level of turbulence there, suggesting that it may reduce or eliminate its deleterious effects on the microwaves.


An encouraging development and a job well done. Hopefully this bodes well as MIT builds their SPARC reactor with a plasma current of 7.5 million amps.

https://www.psfc....cs/sparc
Surveillance_Egg_Unit
2.3 / 5 (12) Aug 24, 2018
From the article - "Temperatures in today's tokamaks—including C-Mod—are not high enough to provide good matching conditions for the wave to transfer all its momentum to the plasma particles on the first pass from the antenna, which launches the waves to the core plasma. Consequently, researchers noticed, the injected microwave travels through the core of the plasma and beyond, eventually interacting multiple times with the edge, where its power dissipates, particularly when the density is high."

A tokamak of any size and construction is NOT the optimum object to use for the purpose of attaining temperatures of ~1 Million C. that would result in Fusion of particles. IF such high temperatures were able to be attained within a tokamak, it would surely result in a complete meltdown of the tokamak and all of its peripherals, and possibly the lab itself.
Fusion of particles can only be done in OUTER SPACE far from gravitational pull of Earth.
Surveillance_Egg_Unit
2.6 / 5 (10) Aug 24, 2018
-CONTINUED-
In outer space, the Sun. for example, is not enclosed by "walls". The energy from the Sun is radiated outward in its Solar Wind and its Solar Flares with very little obstruction. Its radiative effects can interact with planetary bodies, but otherwise the SW/particles freely travels.
In a lab on Earth, any source of energy within the tokamak is bound to collide with the walls rather than raise the temps to cause any Fusion of particles of any length as is required for commercial use.

The article mentions a "Plasma Core" and, presumably, this Plasma Core was attained with the use of Microwaves IIRC. But the energy is hitting and bouncing off the walls of the tokamak and then there is no more progression to a full Fusion reaction as in the Sun.
Such an experiment should be made somewhere between Earth and the Moon without a tokamak enclosure.
There is no description of the "turbulent Plasma fuel" in the article. I would like to know what it is.
Eikka
5 / 5 (10) Aug 25, 2018
IF such high temperatures were able to be attained within a tokamak, it would surely result in a complete meltdown of the tokamak and all of its peripherals


The temperature refers to the average kinetic energy of the ionized particles. It doesn't mean the tokamak is a kitchen oven heated up to 1 million degrees.

The Large Hardon Collider reaches temperatures of 5.5 TRILLION degrees Celsius, but again that's a measure of the beam energy, not how hot the equipment gets.

But the energy is hitting and bouncing off the walls of the tokamak


That's precisely NOT what is happening. The whole point of a tokamak is magnetic containment where the plasma is held OFF the walls by a magnetic field, and any contact is avoided as much as possible.

The problem with the turbulence is that the current and magnetic fields are not stable in all conditions, and when the turbulence appears it causes contact with the reactor walls which instantly cools the plasma down.
Eikka
5 / 5 (7) Aug 25, 2018
There's only a few grams of million-degree ionized gas in the tokamak anyhow, so contact with the internal walls doesn't result in anything dramatic. It's only a concern for the long term operation of the reactor because the ions would be sandblasting at the reactor walls 24/7

And of course, since the thermal mass of the reactor is so much greater than that of the plasma, if the plasma keeps touching the walls it just cools down and the reactor can't work.
Surveillance_Egg_Unit
4 / 5 (4) Aug 25, 2018
@ Eikka
Thank you for your clear and concise clarification of the topic. You have my appreciation.

While the idea of a commercially advantageous workable Fusion process would be perfect to offset fossil fuel usage, I still feel that it would work best in outer space, if it could work at all. For one thing, only a few grams of ionised gas would be inadequate to power a whole planet with enough nuclear energy.
Whart1984
Aug 26, 2018
This comment has been removed by a moderator.
TheGhostofOtto1923
3.8 / 5 (10) Aug 26, 2018
@ Eikka
Thank you for your clear and concise clarification of the topic. You have my appreciation
SEU is the latest incarnation of the idiot obama_socks, pirouette et al as evidenced by the inane religiosity, extraterrestrial bullshit, and notable gems such as
IF such high temperatures were able to be attained within a tokamak, it would surely result in a complete meltdown of the tokamak and all of its peripherals
-and
only a few grams of ionised gas would be inadequate to power a whole planet with enough nuclear energy
This troll likes to feign immense ignorance in order to play adult posters. Why? What kind of imbecile would get enjoyment from this sort of behavior?

Nevertheless it has been their MO with several suckpuppets for many years now.
Eikka
5 / 5 (6) Aug 26, 2018
For one thing, only a few grams of ionised gas would be inadequate to power a whole planet with enough nuclear energy.


E = mc^2

ITER would be consuming about 1.5 grams of hydrogen per hour to put out 500 MW thermal power.
Surveillance_Egg_Unit
4 / 5 (6) Aug 26, 2018
Per hour - huge difference. How will it be fed?

From Wiki wrt ITER - "The containment vessel is subjected to a barrage of very energetic particles, where electrons, ions, photons, alpha particles, and neutrons constantly bombard it and degrade the structure. The material must be designed to endure this environment so that a power station would be economical. Tests of such materials will be carried out both at ITER and at IFMIF (International Fusion Materials Irradiation Facility)."
-- It is this that concerns me most: the Structure of whatever size will eventually degrade and will need to be replaced, rebuilt or reassembled, and the nuclear process ceased. Although a grand idea, I have misgivings.

Incidentally, I checked on Andrea Rossi's "Cold Fusion" website last night and found not much of a change. His answers to direct questions are full of "yes', "no" and as little information as to his claims of "progress" as possible.
Rossi is definitely a charlatan and a phony.
Surveillance_Egg_Unit
4 / 5 (5) Aug 26, 2018
@ Eikka
As an interested observer and a scholar, as well as an environmentalist, I am still in the process of learning from the articles and comments in this website wrt the present and future technical possibilities that science/technology is working on to make a hypothetical dream into reality.
So kindly bear with me as to my apparent lack of scientific knowledge, as I struggle to learn everything to, perhaps assist me in my future reports/job assignments.
Surveillance_Egg_Unit
4 / 5 (4) Aug 26, 2018
(...)which was not predicted by theory. Unless this problem is solved you can't really use this in a reactor
In another words, the hot fusion is as distant as it was before fifty years: every progress just reveals new and new obstacles for it, whereas the success of cold fusion is systematically ignored.

Due to laws of induction, the tokamak transformer can heat plasma only during brief interval of time, when its current rises, which cannot proceed too long, because whole thing would explode. The heating of plasma by microwaves is terribly ineffective and once the plasma gets hot, it becomes opaque for microwaves in similar way, like aluminium foil in microwave oven - and it reflects them outside the reactor..[/q says Whart

Rossi's Cold Fusion is a huge moneymaker from those who have belief and faith in it. The guy is set for life. But it seems that Rossi is now interested only in SELLING the electricity, if any, from his invention, but not the machine itself.
Surveillance_Egg_Unit
4 / 5 (6) Aug 26, 2018
-CONTINUED-

http://e-catworld...cturing/

Rossi is to give a presentation in January 2019. When questioned about the presentation, Rossi replied, to wit: "We aren't ready yet" - presumably to mean that the factory in which production is to be started up isn't ready. It could also mean that, like the tokamak nuclear process, the Cold Fusion is not ready due to it not being an effective means of producing energy/electricity as had been promised before.

I can see why Andrea Rossi is so close-mouthed wrt his Cold Fusion "invention". He opens his mouth to laugh hilariously on his way to the bank, possibly while thinking to himself: "What Fools These Mortals Be". Or something similar in Italian.
LOL
Whart1984
Aug 26, 2018
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Whart1984
Aug 26, 2018
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flueninsky
2.6 / 5 (10) Aug 26, 2018
A typical fusion event - before it ended operation in September 2016
@phys.org Researchers at MIT's Plasma Science and Fusion Centre have now demonstrated how microwaves can be used to overcome barriers to steady-state tokomak operation. In experiments performed on MIT's Alcator C-Mod tokomak before it ended operation in September 2016 research scientist Seung Gyou Baek and his colleagues studied a method of driving current to heat the plasma called Lower Hybrid Current Drive The technique generates plasma current by launching microwaves into the tokomak, pushing the electrons in one direction—a prerequisite for steady-state operation

It is now 3/4s the way through 2018 and were counting on experiments demonstrating the possibility of continuous fusion that had to end in 2016
All be it, this all irrelevant, as there is no element on earth that can withstand breakeven for more than seconds before the evidential shutdown to preserve a multibillion $$$$ meltdown!
antialias_physorg
3.4 / 5 (7) Aug 26, 2018
All be it, this all irrelevant, as there is no element on earth that can withstand breakeven for more than seconds before the evidential shutdown to preserve a multibillion $$$$ meltdown!

luckily no element needs to sustain this temperature, because the plasma is confined in a magnetic field.

Scientists aren't complete idiots, you know?
Whart1984
Aug 26, 2018
This comment has been removed by a moderator.
Whart1984
Aug 26, 2018
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gkam
1 / 5 (9) Aug 26, 2018
Wow, in another 40 years we may actually get one to work.
But we do not need them anymore, even now.
flueninsky
2.5 / 5 (11) Aug 27, 2018
Fusion steam reactor, Relativistic neutrons transfer the fusion heat of fusion
@flueninsky All be it, this all irrelevant, as there is no element on earth that can withstand breakeven for more than seconds before the evidential shutdown to preserve a multibillion $$$$ meltdown!

@antialias_physorg luckily no element needs to sustain this temperature, because the plasma is confined in a magnetic field.
Scientists aren't complete idiots, you know?

The few seconds of each trial test ruins the interior of the reactor shell, it sinters with 100million degree heat and passing relativistic neutrinos, the sintered metal has to be removed to allow the next seconds of firing, it adds impurities into the pristine plasma.
If it was not for the radio-active relativistic neutrons transferring the fusion heat of fusion this highly radio-active fusion reactor would have no means of the lithium plates producing steam
flueninsky
2.8 / 5 (9) Aug 27, 2018
The return of the Flying Scotsman with a Fusion Steam Reactor
What tickles pink about these Fusion Steam Reactors, that if and when small portable fusion steam reactors become a reality, the return of the Flying Scotsman and other famous steam engines are a practical reality
antialias_physorg
3.8 / 5 (5) Aug 27, 2018
it sinters with 100million degree heat

Ah...you're confusing temperature and heat.
Temperature is a property of every plasma particle. Heat is the energy content of the entire plasma.
While temperature is very high heat is pretty low (because the mass of the plasma is low). It's basically how outer space can be very cold even though the atoms you find floating around can have thousands of degrees K temperature.

The walls are built to withstand the emitted neutrons. Note that in fission reactors you also have neutron emission - and the containment vessels aren't falling apart there, either (and those are just made of steel).

As for sintering: No. Neutron bombardment of lithium blanket just produced tritium (which is fed back into the reaction). There's also numerous other material candidates being explored.

Personally I like the liquid lithium approach, but it remains to be seen which is the most economically viable
flueninsky
2.8 / 5 (9) Aug 27, 2018
A New Approach to Fusion July 31, 2009
The prototype reactor will be composed of a metal sphere about three meters in diameter containing a liquid mixture of lithium and lead. The liquid is spun to create a vortex inside the sphere that forms a vertical cavity in the middle. At this point, two donut-shaped plasma rings held together by self-generated magnetic fields, called spheromaks, are injected into the cavity from the top and bottom of the sphere and come together to create a target in the center
On the outside of the metal sphere are 220 pneumatically controlled pistons, each programmed to simultaneously ram the surface of the sphere at 100 meters a second. The force of the pistons sends an acoustic wave through the lead-lithium mixture, and that accelerates into a shock wave as it reaches the plasma, which is made of the hydrogen isotopes deuterium and tritium https://www.techn...-fusion/
flueninsky
2.8 / 5 (9) Aug 27, 2018
With ITER we're looking at 2080 for possible fusion reactors in society
Considering the eternal 30 repetitive yearly Ground Hog Day with ITER, any alternative to ITERS first test firing, 2035 or is it 2040 with a possible test run in 2050 or is that 2060 where in 2060 we won't have a workable ITER, only proof of concept. The total bill so far in 2060 spread throughout the infinitely better alternatives will realise fusion infinitely earlier than 2060 as 2060 from that date production has to start so add that to 2060 and we're looking at 2080 for possible ITER fusion reactors in society!
p.s. don't forget to add the eternal 30 years to ITERs 2080 for possible fusion reactors in society, which just as with last century, in 2110, 2080 will be last century.
antialias_physorg
3.3 / 5 (6) Aug 27, 2018
Considering the eternal 30 repetitive yearly Ground Hog Day with ITER...

I'd like to point out that what ITER (and other fusion experiments) are trying to do is DUPLICATE THE MECHANISM OF THE FRIGGIN' SUN.
I know it's being passed off as blasé in every science fiction novel from A to Z, but let's not kid ourselves. This is about as big of a challenge as you can possibly think of. We're not just banging rocks together, here.

The total bill so far in 2060 spread throughout the infinitely better alternatives will realise fusion infinitely earlier

That's just unsupported hyperbole.

We don't really need fusion on Earth due to how cheap renewables have become (though it certainly would be nice-to-have). However, that wasn't at all the case when this type of research was begun.

But we *will* need it in space (there's basically no currently obvious alternative if we ever want to go a-wandering in any serious fashion)
flueninsky
2.5 / 5 (11) Aug 27, 2018
Atoms in their femto-world have a mathematical means of eking out their energy
There is an alternative, friction due to electrons and protons due to their size and number, they have femto-quanta sized friction, just as energy comes in quantifiable amounts, for example in the electron, it's energy and friction comes in quantifiable amounts, it is how you approach this friction and energy in the quantum-world in its application in the macro-world.
Atoms in their femto-world have a mathematical means of eking out their energy without resorting to radio-active nuclear, fusion and fission energy. A considerable amount is physical – frictional - momentum and magnetic and electrical repulsive and attraction in the electron is how the atoms transfer their energy around.
antialias_physorg
3 / 5 (8) Aug 27, 2018
Atoms in their femto-world have a mathematical means of eking out their energy

Translation? Anyone?
I'm calling "BS word-salad" on that one.

There is an alternative, friction due to electrons and protons due to their size and number, they have femto-quanta sized friction,

More BS word-salad. You very obviously don't even know what the word "friction" means.
flueninsky
2.6 / 5 (10) Aug 27, 2018
Building on renewables, the energy of the femto-world of atoms
@antialias_physorg We don't really need fusion on Earth due to how cheap renewables have become

Wind energy is the transference of the physical momentum of atoms in their femto-world into our macro-world, translating the magnetic field of electrons into physical movement to produce an electric current by the physical repulsion of electrons by their electric field of the turning turbine blades by the momentum of the atmospheric atoms.
flueninsky
2.6 / 5 (10) Aug 27, 2018
antialias_physorg, that was uncalled for, nether the less you brought out a more definitive description of what you're struggling to comprehend, the physicality of the mechanics of one of our favourite renewables, wind energy.
flueninsky
2.6 / 5 (10) Aug 27, 2018
In the femto-world of the atmospherically molecules
@flueninsky Atoms in their femto-world have a mathematical means of eking out their energy without resorting to radio-active nuclear, fusion and fission energy. A considerable amount is physical – frictional - momentum and magnetic and electrical repulsive and attraction in the electron is how the atoms transfer their energy around.

antialias_physorg, the physicality of the theory behind the momentum of atmospheric atoms turning the turbine blades
antialias_physorg
3.3 / 5 (7) Aug 27, 2018
antialias_physorg, that was uncalled for, nether the less you brought out a more definitive description of what you're struggling to comprehend, the physicality of the mechanics of one of our favourite renewables, wind energy.

Erm...whut?
Would you mind writing english sentences?
Hint: Use an subject, a verb and (optional) an object.

And I'm still calling BS on the "femto quanta sized friction" and the "mathematical means of eking out their energy"

Show the math (particularly the 'quanta' part) or admit that you're posting pure BS.
TheGhostofOtto1923
4.1 / 5 (9) Aug 27, 2018
Yo idiot suckpuppet
A New Approach to Fusion July 31, 2009
The prototype reactor will be composed of a metal sphere about three meters in diameter containing a liquid mixture of lithium and lead. The liquid is spun to create a vortex inside the blaaaah
-If you're here to play games, why use a 10yo ref instead of using the general fusion website so people might think you're, you know, smart? What, dont know how to spell website?

Stupid suckpuppet.
flueninsky
2.5 / 5 (11) Aug 27, 2018
The Art of Conversing – start describing conversational pieces in swear word descriptives
antialias_physorg, that was uncalled for, nether the less you brought out a more definitive description of what you're struggling to comprehend, the physicality of the mechanics of one of our favourite renewables, wind energy.

Erm...whut?
Would you mind writing english sentences?
Hint: Use an subject, a verb and (optional) an object.

And I'm still calling BS on the "femto quanta sized friction" and the "mathematical means of eking out their energy"

Show the math (particularly the 'quanta' part) or admit that you're posting pure BS.

antialias_physorg, you certainly can keep a good flowing conversation, your masterpiece of intellectual understanding that your still calling (swear word) on this.
TheGhostofOtto1923
3.4 / 5 (10) Aug 27, 2018
Yo stupid fluinsky suckpuppet

You guys are here to discredit this site arent you?

Arent you, smelly suckpuppet?
flueninsky
3 / 5 (10) Aug 27, 2018
Otto on fusion
@antialias_physorg Personally I like the liquid lithium approach, but it remains to be seen which is the most economically viable
Yo idiot suckpuppet
A New Approach to Fusion July 31, 2009
The prototype reactor will be composed of a metal sphere about three meters in diameter containing a liquid mixture of lithium and lead. The liquid is spun to create a vortex inside the blaaaah
-If you're here to play games, why use a 10yo ref instead of using the general fusion website so people might think you're, you know, smart? What, dont know how to spell website?
Stupid suckpuppet.

I have no interest in at all Otto, it does not as you have pointed out, have a realistic solution to fusion as the alternative solution of antialias_physorg that you have dismissed out of hand.
flueninsky
3 / 5 (10) Aug 27, 2018
Otto on fusion
We all could delve deeper in this liquid lithium fusion approach Otto, but it would not lead to any fruit full outcome, as you know is was the first of a cursory search which if worthy of merit, would qualify for further research Otto.
TheGhostofOtto1923
3.8 / 5 (10) Aug 27, 2018
I have no interest in at all Otto, it does not as you have pointed out, have a realistic solution to fusion as the alternative solution of antialias_physorg that you have dismissed out of hand
I do agree that mods should be a little more actively involved in keeping obvious vandals off of this otherwise excellent site.

Stinking suckpuppet.

How about a nice game of 'Madden NFL 19'? Quite the rage in Moronistan I hear.
flueninsky
3 / 5 (11) Aug 27, 2018
As you can see Otto, the date on that article is 2009, is an indicative date to a realistic proof of concept to a fully working experimental reactor is going to take a lot longer than the repetitive 30 years, and the billions of $$$$ required, the $$$ are what in its all about Otto.
flueninsky
3.2 / 5 (11) Aug 27, 2018
Little Children are able to read this Site Otto
I have no interest in at all Otto, it does not as you have pointed out, have a realistic solution to fusion as the alternative solution of antialias_physorg that you have dismissed out of hand
I do agree that mods should be a little more actively involved in keeping obvious vandals off of this otherwise excellent site.
Stinking suckpuppet.
How about a nice game of 'Madden NFL 19'? Quite the rage in Moronistan I hear.

We all agree with you Otto, we like to keep this site clean with no bad language and no swear words, as there are no restriction on this site, and our up and coming scientists - Little Children are able to read this Site Otto, so please bear that in mind
gkam
1.8 / 5 (10) Aug 27, 2018
We will not have fusion as our important power source, . . ever.

And we cannot protect children from hateful people like we thought we could. The internet has enabled the Ottos and the Putins.
Mark Thomas
3 / 5 (8) Aug 27, 2018
But we do not need them anymore, even now.


gkam, while I share your affinity for renewables, why can't you understand we need fusion? Renewables only work within a certain distance of a star, beyond that, they are useless. We cannot boldly go with renewables alone any more than we could with coal alone.

As a practical matter, we need practical fusion power plants both on Earth and beyond. I read about the dying coral reefs around the world and hope there will be enough left on Earth to salvage by the time we finally turn all these environment calamities around. If I could choose one technology worthy of Manhattan Project or Apollo Project levels of extreme focus, I would choose practical fusion power.
Mark Thomas
3.4 / 5 (10) Aug 27, 2018
gkam, I would also point out that solar power and wind power are both derived from fusion in the sun.
antialias_physorg
3.3 / 5 (7) Aug 27, 2018
There's also parts of the world where fusion would be welcome (Anywhere north of the arctic circles. Anywhere south of the antarctic circle). If we ever want to have underwater habitats then fusion power would certainly be a good idea as wind/solar isn't available (wave/flow/tidal might be, though)

It might also be useful for installations that require a big and constant energy input (e.g. stuff like the LHC or large scale water desalination plants which we will require in the future when the glaciers have melted and a lot of rivers/lakes will have dried up)
antialias_physorg
3 / 5 (6) Aug 27, 2018
antialias_physorg, you certainly can keep a good flowing conversation, your masterpiece of intellectual understanding that your still calling (swear word) on this.

Aaaah...the weasel cops out. So predictably.

C'mon. You claimed there's math. Show us the math. That should be easy to do, right? Just google it and post the link. Easy as pie.
Hyperfuzzy
not rated yet Aug 27, 2018
There is no density limit; at least at that level and pressure. What you are trying to do can't be accomplished in that manner; instead of forcing fusion, allow it; however, why do you expect energy from a transformation that has a quieter result?
gkam
1 / 5 (7) Aug 27, 2018
Mark, thanks for the note. Your suppositions are valid, but we cannot depend on something we do not have yet. If we get it, at what cost to society?
gkam
1.5 / 5 (8) Aug 27, 2018
Mark, I do not want to be dependent on some huge remote and powerful complicated powerplant. And I put my money where it counts, I have a PV system which powers my household and two electric cars.

Distributed power sources provide much better coverage, reliability, stability, and cost advantages than central plants owned and operated by others out of our control.
Hyperfuzzy
5 / 5 (2) Aug 27, 2018
Mark, I do not want to be dependent on some huge remote and powerful complicated powerplant. And I put my money where it counts, I have a PV system which powers my household and two electric cars.

Distributed power sources provide much better coverage, reliability, stability, and cost advantages than central plants owned and operated by others out of our control.

Exactly! A completely controlled grid; the more the merrier! City Art and Solar Wind then a Rescue center! You will need a logical society as a necessary condition.
flueninsky
2.8 / 5 (9) Aug 27, 2018
Ideas on Energy or where's your mathematics
@flueninsky Atoms in their femto-world have a mathematical means of eking out their energy

it is simply the mathematics of momentum, electrical and magnetic imparting momentum resulting in kinetic energy which turn the wind turbines antialias_physorg, were talking about ideas of extracting energy, you could quite easily ask, where's the mathematics in constructing the fusion reactor core for extracting fusion waste.
For every conceivable idea that has ever been thought of there is mathematics to describe it's construction and mathematics of operation antialias_physorg, is this half a hole that is being dug antialias_physorg or am I missing the other half of the hole.
flueninsky
2.8 / 5 (9) Aug 27, 2018
antialias_physorg, "Atoms in their femto-world have a mathematical means of eking out their energy" was not specifically about renewables in wind turbines, but as you brought up another energy alternative it allowed you an avenue for you to see further into the theory "Atoms in their femto-world have a mathematical means of eking out their energy" likened to stepping stones to that stepped board, which I though you would make that step, I was not thinking of what I call diversionary tactics, as I don't know what you call them.
humy
5 / 5 (1) Aug 27, 2018
In another words, the hot fusion is as distant as it was before fifty years:
Whart1984

That may or may not be true; I have no personal opinion on that. Only a real expert is likely to have a completely self-formed valid opinion on that and the rest of us usually can only form a valid opinion on that by listing to their expert opinions; that is why we employ them after all.
But, what you don't get is that, because in other posts you have repeatedly shown you are a delusional nut that doesn't understand basic physics but has the delusion you know everything about it and better than people who are smarter than you and me, your expressed opinion on it or anything else to do with physics means nothing i.e. is completely worthless.
TheGhostofOtto1923
3.9 / 5 (7) Aug 27, 2018
We all agree with you Otto, we like to keep this site clean with no bad language and no swear words, as there are no restriction on this site, and our up and coming scientists - Little Children are able to read this Site Otto, so please bear that in mind
And a turd is a turd no matter what the language little fluinsky.
humy
5 / 5 (1) Aug 27, 2018
...by listing to their expert opinions; ...

My misedit; "listing" above should be "listening"
Whart1984
Aug 27, 2018
This comment has been removed by a moderator.
Mark Thomas
3 / 5 (8) Aug 27, 2018
Mark, I do not want to be dependent on some huge remote and powerful complicated powerplant. And I put my money where it counts, I have a PV system which powers my household and two electric cars.


I understand and I hope to be a very proud owner of a Tesla 3 by the end of the year too. I have been watching Tesla build out their solar plant in Buffalo, New York and hope to be able to order from them some day too. Even so, I remain a huge fan of fusion for all the reasons myself and others laid out above. Another thing to consider is that we don't have the luxury of time to correct global warming. This is tantamount to a war we are losing and we need to get every weapon we have to the front right now. Solar, wind, nuclear fission, nuclear fusion, whatever works. Things are getting serious far more quickly than we thought they would. We need to stop acting like we have forever and get ourselves off of fossil fuels yesterday.
gkam
2.3 / 5 (9) Aug 27, 2018
Hot fusion is too complex to be good for us. I was really hoping cold fusion would have worked.
gkam
2.3 / 5 (9) Aug 27, 2018
I thought cold fusion might allow individual or neighborhood power systems.
Centralized plants lead to centralized control, . . of us.
Whart1984
Aug 27, 2018
This comment has been removed by a moderator.
Mark Thomas
3 / 5 (6) Aug 27, 2018
Hot fusion is too complex to be good for us.


There is no doubt that hot fusion is a very hard problem, but based on everything I have read, I believe we will solve the problem of practical fusion power. It reminds me of President Kennedy's famous speech at Rice University, i.e., "We choose to go to the moon in this decade and do the other things, not because they are easy, but because they are hard." Now why do such good things always have to be hard? Perhaps we need a philosopher to answer that one.
Whart1984
Aug 27, 2018
This comment has been removed by a moderator.
humy
5 / 5 (2) Aug 28, 2018
That may or may not be true; I have no personal opinion on that... your expressed opinion on it or anything else to do with physics means nothing i.e. is completely worthless
In another words it remains valid, .
Whart1984

I CLEARLY just implied your opinion is NOT valid. Can't understand plain English?
antialias_physorg
3.3 / 5 (7) Aug 28, 2018
Ideas on Energy or where's your mathematics

No. You do not get off the hook that easy.
I want a definition what "femto-QUANTIZED friction" is supposed to mean. Where do you get the 'quantized'. You claimed this was mathematical. Show the math or link to it. Otherwise bow out and admit to posting BS.

I have no problem with people being dumb. I have a problem when people, like you, are trying to feign being smart (particularly when they don't realize how super-dumb that makes them look)

or am I missing the other half of the hole.

The one in your head?

"Atoms in their femto-world have a mathematical means of eking out their energy""Atoms in their femto-world have a mathematical means of eking out their energy"

Do you even know what "to eke out" means? What you are claiming is a direct contradiction to conservation of energy.

(And why the femto-world...what is that even supposed to mean? Atoms don't work in the pico scale or what?)
flueninsky
2.3 / 5 (12) Aug 28, 2018
antialias_physorg, in your own imitable style, you're intrigued, the proton starts in the Femto-world and smaller where as I look at it as just a dimension of scale in the vacuum these atoms occupy.
Since the sixties friction has been described as unique quantifiable units of energy where spin is incrementally reduced by these frictional quantifiable units.
The mathematics of incremental deceleration are the same as incremental acceleration are identical in the energy required for each increment as one of the overriding observations on phys.org is when you work other user idea's in your mind's eye it satisfies your own curiosity then you arrive bright eyed and bushy tailed full of enthusiasm with insight that only someone who see's the idea from a perspective of impartiality with no intention of simply scoring points, you have probably gathered I'm not interested in scoring points but I am quite adept at spotting half a hole when I see one.
jonesdave
3 / 5 (8) Aug 28, 2018
.......but I am quite adept at spotting half a hole when I see one.


And still managing to fall into it!
antialias_physorg
3 / 5 (8) Aug 28, 2018
but I am quite adept at spotting half a hole when I see one.

The only thing I see you being adept at is spouting word salad and unsupported nonsense.

Still waiting on the math/link. What is it? Can't you produce? Scared of being found out you're nothing but an impostor? (Don't worry - that you already accomplished with your first post)
flueninsky
2.5 / 5 (11) Aug 28, 2018
I didn't even have time to make a cup of tea
with insight that only someone who see's the idea from a perspective of impartiality with no intention of simply scoring points, you have probably gathered I'm not interested in scoring points but I am quite adept at spotting half a hole when I see one

and it's already disappeared down the rabbit hole, Bugsy is digging the holes other half over the hill.
flueninsky
2.2 / 5 (10) Aug 28, 2018
With all these half a holes
I didn't even have time to make a cup of tea
with insight that only someone who see's the idea from a perspective of impartiality with no intention of simply scoring points, you have probably gathered I'm not interested in scoring points but I am quite adept at spotting half a hole when I see one

and it's already disappeared down the rabbit hole, Bugsy is digging the holes other half over the hill.

We must be dealing with a physic imposter, some imposter, a contradiction in terms.
flueninsky
1.9 / 5 (9) Aug 28, 2018
When the earth accelerates the moon there is no reactive gravitational force on the earth
The mathematics of incremental deceleration are the same as incremental acceleration are identical in the energy required for each increment
antialias_physorg, as you know when the earth accelerates the moon there is no reactive gravitational force on the earth and the same when the moon accelerates the earth there is no reactive force on the moon, this is how the atoms in their femto-world exchange their forces in their quantum world, when for example the pion decays accelerating a muon to C there is not reactive force as this all occurs in the quantum world
This is an important aspect of how atoms in their quantum world eke out forces and energy as antialias_physorg, you must realise the implication of the proton and its reactionless inertial force
flueninsky
2.6 / 5 (5) Aug 28, 2018
Well I never, that's a turnabout for the books.
When the earth accelerates the moon there is no reactive gravitational force on the earth
The maths of incremental deceleration are the same as incremental acceleration are identical in the energy required for each increment
antialias_physorg, as you know when the earth accelerates the moon there's no reactive gravitational force on the earth, when the moon accelerates the earth there is no reactive force on the moon, this is how the atoms in their femto-world exchange their forces in their quantum world, when for example the pion decays accelerating a muon to C there is not reactive force as this all occurs in the quantum world
This is an important aspect of how atoms in their quantum world eke out forces and energy as antialias_physorg, you must realise the implication of the proton and its reactionless inertial force

It's always the unexpected that is the most interesting, not what was expected at all.
Eikka
5 / 5 (1) Aug 31, 2018
Per hour - huge difference. How will it be fed?


Difference to what?

How the fusion reactor is supposed to work, the photons are absorbed in the mass of the reactor walls which heat up, which causes water to boil, which runs a turbine generator.

The particle radiation is different. Electrically charged particles are trapped by the magnetic field, but neutral particles (neutrons) hit the reactor walls. If the neutron has enough speed, it hits some nucleus. If not, the neutron bounces around for about 11 minutes before breaking down into a proton and and electron and a neutrino - a hydrogen atom plus some extra.

By lining the reactor walls with lithium, the neutron bombardment transmutes the lithium and results in the creation of tritium gas - heavy hydrogen, or fusion fuel. The rest of the neutrons that don't have the right speed get lodged in the reactor wall and turns into hydrogen, which causes embrittlement in metals, but can be dealt with.

Eikka
5 / 5 (1) Aug 31, 2018
The trick is that hydrogen diffuses through metals at high temperatures, so when the reactor walls are hot (400-500 C - enough to make superheated steam for the generator), the tritium and regular hydrogen diffuse out towards the vacuum chamber, where they will hit particles of hot plasma and get ionized, and join the fusion reaction. The hydrogen atoms that offgas from the walls into the vacuum chamber are like hedgehogs trying to walk across a four-lane highway - sooner or late it's a splat - but if they do get lucky then they get sucked off by the vacuum pump and recycled.

For the fuel that isn't generated by neutron bombardment of the reactor lining, neutral beam injection is used to squirt a shot of hydrogen (deuterium, tritium) into the plasma. Collisions within the plasma heats it up to ionization, so you can keep feeding in fuel in a thin stream as the reactor operates.

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