Tokamak...Hidden Dangers?

reply to post by C0bzz

More fear mongering paranoia with no basis. It truly is pathetic.

Actually, I was asking questions because I don't know. It's not fear mongering to ask questions.

It's a subject that interests me but I just don't know enough about it.

Like for instance, they can create this super hot plasma, yet do they inject that plasma with hydrogen fuel? Something to sustain the fusion process?

reply to post by whatukno

they can create this super hot plasma, yet do they inject that plasma with hydrogen fuel? Something to sustain the fusion process?

I'm pretty sure that they are not at that stage of development.

Here is how a Tokamak works:

1. The chamber is placed under vacuum (air sucked out)

2. The walls contain magnets that creates magnetic field lines that form a circle within the vacuum sphere, and do not touch the walls of the chamber.

3. Hydrogen is heated, usually by Microwave or Radio EM fields.

4. Hydrogen is injected into the Chamber, and circulates within the magnetic field, suspended from the walls of the chamber.

5. EM energy is pumped into the plasma (again, like a microwave oven)

6. The Hydrogen heats up to 100,000,000 degrees Celsius.

7. Fusion Occurs

8. ???

9. Profit.


This is the step we are at now.

We can achieve fusion within the vessel.


We must now learn to Stabilize the reaction (so that it is self sustaining) and gather energy from it (bootstrap current, and magnetic flux, or thermal, EM antenna, etc...)

hydrogen preheat will more than likely be using conventional methods, with the addendum that it would be powered by the Fusion Reaction itself.

-Edrick

reply to post by whatukno


I think perhaps you are onto something but I also think you may be overreacting. Think of it this way. The earth's magnetic field Is hugely strong. And I'm not sure how to extrapolate the size of it but understand that the world is something like 26000 kilometers around. As the furry texan stated, the dangers of the Tokamak are highly localized. Think of the tokamak's enegry field as something like a ball of lead slightly larger than a baseball.. And then picture the earth's magnetic field as an aluminum can the size of a football stadium. The ball, while technically of more mass in a very localized area (somewhere almost lost inside this enormous can..) There is no real danger posed to the can by the ball.

As for the temperature factor, well, lightning is allegedly as hot or hotter than the sun. It even has a tendency to violently rip apart molecules unlucky enough to be in the way. Crackaboom. And it's a natural part of the Earth's weather. I don't feel we have anything to fear from experimentation with Tokamak. It's becoming more and more a necessity as we run out of other sources of energy.

When dealing with plasma, the main issue is that you are dealing with the single most corrosive thing in existance. Now, heat that up to a few thousand degrees kelvin and you have potential for a start of creating a fusion reaction. That is the single largest obstacle that must be overcome with plasma technology period. (and other complications that arrive with it) Heating the plasma with electro magnetism is pretty cool, not very similar to using microwave radiation for heating, but is very efficient, and is the subject to extreme magnetic flux density. But, as the baseball-stadium analogy put it, it is not about to cause damage to the earth's magnetic field.

Until plasma can be properly contained, AND enough energy can be extracted from the system for overunity, there is pretty much no way fusion will every get anywhere. I do agree that you should be much more worried about the LHC, than about this dinky little fusion experiment.

Lightning is hotter than sun, but sun's core is even far hotter where multi-billion dollar machine for generating electricity via fusion reaction are even far hotter than sun's core so the plasma that inside tokamak reactor are also much hotter than Lightning

Originally posted by LeeTheDestroyer
When dealing with plasma, the main issue is that you are dealing with the single most corrosive thing in existance. Now, heat that up to a few thousand degrees kelvin and you have potential for a start of creating a fusion reaction.

As a humble PhD in physics, I can only certify the above is inaccurate (and, in the eyes of some, potentially moronic).

Heating the plasma with electro magnetism is pretty cool, not very similar to using microwave radiation for heating

Microwave radiation is electromagnetic. Now, get that foot out of your mouth, please.

I do agree that you should be much more worried about the LHC, than about this dinky little fusion experiment.

I visit the LHC on a regular basis and I feel completely relaxed (nice cafeteria, by the way, and they serve wine for $2 for a small glass). What the heck is all the hysteria about?

Ignorami, be gone.

reply to post by buddhasystem


Ok maybe you can help me understand better.

So, they take, what, Hydrogen and heat it up to an astronomical temperature right? This is in what is essentially an electromagnetic jar, so that it doesn't go anywhere. Now they can only produce a fusion reaction for a few seconds right?

Now correct me if I am wrong, but isn't the problem pressure, or more specifically gravity? I mean they can put as much Hydrogen as they want and burn it off this way but without pressure from gravity it doesn't seem to me that you are going to get H to He by turning it into plasma alone.

Now if one was able to do this, the theory is, an electron or two from this fusion would break off and it could be collected for use as electricity.

Am I way off here?

reply to post by whatukno


My friend,

why do you think gravity needs to play a role?

It doesn't. In stars, it does create the pressure needed for the fusion, but in apparatus like Tokamak conditions are way different.

reply to post by buddhasystem


I think that gravity needs to play a role because you are going to need so much mass of H in order for it to fuse into He that it's going to have a gravitational well.

I don't really know, it's something interesting that I don't know much about.

Here is a thread I just started linking to a Virtual Tokamak. You can futz with the three primary settings to try and get the maximum efficiency.

If nothing else, it gives some context to those having difficulties grasping the concept of the tokamak.

Try it here

To create the pressure required they create an extremely intense magnetic field. No gravity required.

Originally posted by whatukno
reply to post by buddhasystem

 

I think that gravity needs to play a role because you are going to need so much mass of H in order for it to fuse into He that it's going to have a gravitational well.

No, there are other ways to contain plasma other than gravity and tokamak is using magnetic fields for that. For that matter, it would still work in zero gravity conditions. And the mass of the fuel in the tokamak is really tiny anyhow.

Originally posted by whatukno
its because I don't know that I ask.

Whats odd about this is the new ITER project being constructed in France

en.wikipedia.org...

www.iter.org...

The temperatures here are astronomical, and the magnetic field generated is the scarry part. How do we know if that magnetic field won't warp Earths own magnetic field and completely disrupt the poles?

Robert Bussard says Tokamaks are a bad idea, and has a better
way to do Hot Fusion.

en.wikipedia.org...

His Google Talk is here:

Google Video Link

The ppl pushing the focus fusion say there method is even better
than Bussard's.

Google Video Link

Magnetism gets weaker over distance, you can test this theory with even
a powerful magnet from a dead microwave oven.

The element in the microwave is similar to the one used in a RADAR
that works on the Doppler principle, aka a Magnetron.

en.wikipedia.org...

The one that was a part of my radar had a magnet so powerful
it would destroy digital watches that came near it.

Low power magnetic fields can cause DNA damage.

www.sciencedaily.com...

So High Power magnetic fields wreak tremendous damage.

The DNA warping will be localized and is still much smaller than
the magnetic field of the earth.

Electricity flowing thru high power lines are radon attracters
that lead to higher cancer rates for those living near them.

www.rag.org.au...

Partly why I am for service tunnels underground for power lines
as it will also allow for longer lasting lines, and no damage
from severe storms.

The tunnels could have Mu Metal shielding that shunts the
magnetic radiation, and the same can be done for the ITER.

en.wikipedia.org...

This is on Air Force one and other constructs for EMP shielding.

The earth's magnetic field however protects us from radiation
that also damages tissue and a increase in skin cancer has
already begun and will increase til the Geo Magnetic Reversal
completes that is already under way.

en.wikipedia.org...

We are overdue for a magnetic polar flip based on prior flips that
are recorded in magnetic rock in various places around the world.

Our magnetic field will be gone for awhile and we will be exposed
to the solar wind for up to years.

They cover this pretty well in the film Magnetic Storm by NOVA.

Google Video Link

NOVA is funded by some bad ppl, but their presentation is pretty
good for the time it was filmed.

[edit on 19-8-2010 by Ex_MislTech]

reply to post by whatukno

I think that gravity needs to play a role because you are going to need so much mass of H in order for it to fuse into He that it's going to have a gravitational well.

Are you talking about Relativistic mass increase due to proximity of Velocity to C?

Yes... I suppose that would happen... however, the speeds of the particles within the magnetic field would have an insubstantial velocity to make any relevant addition to its mass.

The Average distribution of Energy levels within the Tokamak Reactor is:

In 1968, at the third IAEA International Conference on Plasma Physics and Controlled Nuclear Fusion Research at Novosibirsk, Soviet scientists announced that they had achieved electron temperatures of over 1000 eV in a tokamak device.

-Wiki

For comparison:

* ~624 EeV (600,000,000 TeV): energy needed to power a single 10 watt light bulb for one second. (100W = 100J/s = ~6.24x10^20 eV/s).
* 300 EeV (300,000 PeV) :[6] the so called Oh-My-God particle (the most energetic cosmic ray particle ever observed).
* 14 TeV: the design proton collision energy at the Large Hadron Collider (which has operated at half of the energy since March 30, 2010).
* 1 TeV: A trillion electronvolts, or 1.602×10−7 J, about the kinetic energy of a flying mosquito.[7]
* 210 MeV: The average energy released in fission of one Pu-239 atom.
* 200 MeV: The total energy released in nuclear fission of one U-235 atom (on average; depends on the precise break up).
* 17.6 MeV: The total energy released in the fusion of deuterium and tritium to form He-4 (also on average); this is 0.41 PJ per kilogram of product produced.
* 1 MeV: Or, 1.602×10−13 J, about twice the rest mass-energy of an electron.
* 13.6 eV: The energy required to ionize atomic hydrogen. Molecular bond energies are on the order of one eV per molecule.
* 1.3 to 2.1 eV: the photon energy of visible light.
* 1/40 eV: The thermal energy at room temperature. A single molecule in the air has an average kinetic energy 3/80 eV.

-Also, Wiki

So, an average energy of 1,000 electron volts, with a total mass of 50 grams....

Would not really be that much energy, at all.

-Edrick

reply to post by buddhasystem


Okay Sir, As I am so inaccurate in my above statement(s) Would you care to share with me how the use of electro-magnetic compression for heating a plasma is the same as the application of microwave radiation in heating? I would truely like to know the difference if there is one.

Originally posted by buddhasystem

Originally posted by LeeTheDestroyer
When dealing with plasma, the main issue is that you are dealing with the single most corrosive thing in existance. Now, heat that up to a few thousand degrees kelvin and you have potential for a start of creating a fusion reaction.

As a humble PhD in physics, I can only certify the above is inaccurate (and, in the eyes of some, potentially moronic).

Additionally, would you care to explain to me what exactly you are callling inaccurate and potentially moronic here? Is it that plasma isnt "corrosive?" that the ionic bond that an ionized atom in a plasma state would potentially create with any surrounding material would not be enough to overcome the metallic bonds present in most containment matrial. Would not the plasma destroy its containing material or at least damage it, if it were to make physical contact? Or is there no need for an evacuated reaction chamber and magnetic containment?

Is the statement "potential for creating fusion" what merits your negative response? Might I submit that my intent with that statement was to exclaim where I was proceeding with my sentence, I was not intending to imply that "heating plasma equals fusion" if that is how I came off, I do apologize. I do understand that there is much more to the reaction than heating some plasma. So, unless we are talking about cold fusion (Gluon style, not that Utah palladium crap), I do not believe that I am in the wrong about heating a plasma as a part of the process.

Would you please explain? One can only gain knowledge by actively engaging with one who knows more about the topic at hand. I do wish to learn more from you if you so care to share, as your education in the matter far surpasses what I accomplished to date. Constructive critism is what makes the world go round, and those who can take it and use it to their advantage are more likely to progress.

With all sincerity,

Lee

[edit on 22-8-2010 by LeeTheDestroyer]

Something still for some reason tells me that the reason that this doesn't work (Nuclear Fusion) Is because of mass.

I don't know enough about this subject to tell you exactly why I think this. But it seems to me that part of the reason that it works in stars is because of the mass of the star.

reply to post by whatukno


Some gas law, I can't remember the name of it:

pv=nrt
Pressure[kpa]*Volume [liter] = (mass/molar mass)*8.31*temperature[Kelvin]

As pressure goes up, so does temperature. Fusion requires a high temperature and pressure to occur. In stars the high pressures and temperatures are accomplished by a large mass coupled with gravity. In fusion reactors we accomplish this with extremely powerful electromagnets or lasers. The problem is you need extremely powerful electromagnets or lasers to do this that at the moment use more power than the reaction itself puts out. ITER is designed to change this, putting out 5 times the input power. DEMO is designed to put out 25 times. My problem with fusion is that although I think we could eventually make it work it will take a huge amount of time and money to get there. Advanced fission concepts can do everything fusion can, but could be implemented on a much shorter timespan. ITER is expected to cost 20 billion dollars and won't output any energy to the grid... with that amount of money we could develop and implement technologies such as this that have most of the advantages of fusion.

There's some theories about cold fusion which apparently have none of the disadvantages of hot fusion. You can wikipedia them because I am uninterested in hoaxes (my opinion on cold fusion). As far as safety issues with fusion, there are none that I know of. The reaction stops if conditions leave very small parameters.

reply to post by C0bzz

As pressure goes up, so does temperature. Fusion requires a high temperature and pressure to occur.

This is not Accurate.

Fusion only requires enough energy to overcome valance shell repulsion, so that the nuclei can meet, and Fuse.

In a Tokamak, this is accomplished through Thermodynamic Effect. (Hot atoms move faster than cold atoms*BANG*)

Therefore, the Reaction inside the chamber is actually closer to vacuum than it is to Atmospheric Pressure (14.7psia, or 101Kpa if you prefer.)

My problem with fusion is that although I think we could eventually make it work it will take a huge amount of time and money to get there.

If we keep our blinders on about *HOW* to crack the Valance Shell Repulsion effect, then yes... I agree.


Also... the Design of the Fusion Chamber itself could be better.

with that amount of money we could develop and implement technologies such as this that have most of the advantages of fusion.

Except for the problems of the Global Uranium Monopoly.


-Edrick

I stand corrected on fusion.

Except for the problems of the Global Uranium Monopoly.

Uranium currently makes up 2%-4% the cost of operating an existing nuclear reactor. These reactors are between 100 and 200 times more efficient. It wouldn't really matter if you expanded the cost of Uranium by a couple orders of magnitude because it wouldn't change the economics. At these efficiencies it becomes economic to simply put filters in the ocean which collect uranium that is naturally in the sea. Besides the starting charge (which could be provided by reprocessed spent fuel, or old nuclear weapons anyway), no enrichment is required either. There would be no monopoly, and even today any such monopoly doesn't really matter because uranium so so cheap.

reply to post by C0bzz

It wouldn't really matter if you expanded the cost of Uranium by a couple orders of magnitude because it wouldn't change the economics.

I can respect that...

But I was referring to Control, rather than Price as the concern.

And possibly, Quantity. (Although that would be a bit further down the road. admittedly)

At these efficiencies it becomes economic to simply put filters in the ocean which collect uranium that is naturally in the sea.

Yes, I have heard of this, and it is an interesting idea.

But where would you put your filters, whilst in Orbit, or Trans-Orbit?

I like Fusion, because it Runs off of the most Abundant chemical Element in the Known Universe.

Hydrogen.


We have ice on several moons in the solar system.... and we could even set up Giant Magnetic Bussard Collectors in Gravitational Lagrange orbit around the earth to soak up the solar wind.

Feed it into a fusion reactor... *BAM*

A power source that works in 99.7% of the Observable Universe.

because that's how much of the universe is Fuel.


LOL!


Fusion = Awesome!

Besides the starting charge (which could be provided by reprocessed spent fuel, or old nuclear weapons anyway), no enrichment is required either.

Well, that is certainly a Plus.

There would be no monopoly, and I am unsure of any monopoly that exists today given how cheap it is.

en.wikipedia.org...

-Edrick