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Author Topic: Could this be a viable fusion reactor?  (Read 3928 times)

Offline tnhfr1

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Could this be a viable fusion reactor?
« on: 09/12/2015 04:20:40 »
I have been able to hold plasma using 2 cathodes and an anode.
If this where sized up, could this be used as a viable fusion reactor?



 

Offline evan_au

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Re: Could this be a viable fusion reactor?
« Reply #1 on: 09/12/2015 09:16:55 »
That's a nice video of your experiment!

To produce energy using controlled nuclear fusion, you must meet the Lawson criterion. You need:
  • High temperature
  • High Pressure
  • For a long time
  • ...with the right fuel 

It is not enough to simply scale up an apparatus like this, because:
  • You need to keep the hot plasma away from the walls of the vessel, or it will burn through. Any foreign atoms in the plasma will poison the plasma. Preventing this requires tricks like strong, complex, magnetic fields.
  • You need to heat the plasma without electrodes, or the plasma will burn them away. This requires tricks like neutral beam injection, and induced currents in the plasma (typically requiring cryogenic superconducting magnets)
  • The heat of the arc escapes by radiation. You should make the vessel reflective (but it makes for a boring Youtube video!)
  • You need to get fresh fuel in, and waste products out, all without disturbing the Lawson criterion.
ITER is a current project aiming to scale up nuclear fusion. I'm afraid that it's a bit more complex than a neon lamp.
 

Offline tnhfr1

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Re: Could this be a viable fusion reactor?
« Reply #2 on: 09/12/2015 14:37:50 »
Thank you for your reply.
The plasma is away from the walls as it is pulled toward the cathodes in the center and the camber. The walls can be positively charged and be made of lithium if you want to breed tritium.
Particles with higher energy should be kept from colliding from electrodes due to angular momentum. And because of the negative conductor, the insulator would have a slight positive charge.
Mechanical pressure can be applied to the gas and therefore the plasma at higher voltages.
I can hold this plasma indefinitely.
Yes, it would make a great neon lamp, but what if it was this simple.
 

Offline evan_au

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Re: Could this be a viable fusion reactor?
« Reply #3 on: 09/12/2015 20:37:28 »
Quote from: tnhfr1
The plasma is away from the walls as it is pulled toward the cathodes in the center and the chamber.
At present, the plasma does not touch the walls because it is surrounded by non-ionized air. Unfortunately, this carries away a lot of heat via convection.

A plasma is hot, and hot things expand. To produce fusion, it needs to be hot enough for the plasma to fill the entire chamber. Then you need to keep it away from the walls.

Quote
The walls can be positively charged
A plasma consists of positive and negative ions. If the walls are positively charged, they will attract the negative ions, so the walls will become an electrode in the discharge.

Erosion of the walls will introduce metal ions into the plasma, which means it is no longer a perfect plasma (it is very hard to completely ionize metals).
 

Offline tnhfr1

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Re: Could this be a viable fusion reactor?
« Reply #4 on: 09/12/2015 21:32:23 »
The hotter the plasma becomes, the more influenced it will be by the electric charge. 
If the cathodes charge is high enough, won't that keep plasma away from the walls (which of neutral potential in my experiment)?
Plus if the orbit of the plasma becomes organized, wouldn't it create its own magnetic field, a plasmoid?
By the way, the plasma would be heated by pulsing the current at the resonate frequency of the fuel.
 

Online chiralSPO

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Re: Could this be a viable fusion reactor?
« Reply #5 on: 10/12/2015 00:47:34 »
The hotter the plasma becomes, the more influenced it will be by the electric charge.

Unfortunately that is not right. Fusion requires extreme temperatures to overcome the electric repulsion between the protons in the plasma. Once the gas is hot enough to be ionized there is no increase in electrostatic influence tied to increasing temperature. Then higher temperatures serve to reduce the relative effect of the electric fields.
« Last Edit: 14/12/2015 02:42:33 by chiralSPO »
 

Offline evan_au

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Re: Could this be a viable fusion reactor?
« Reply #6 on: 10/12/2015 10:27:32 »
Quote from: tnhfr1
if the orbit of the plasma becomes organized, wouldn't it create its own magnetic field?
Yes. Fusion reactors often use electromagnetic induction to produce currents in the plasma, heating it, and also helping to contain it.
Quote
a plasmoid?
The original 1950s concept of a plasmoid seems to be something that forms naturally, and is fairly stable.
However, a high-temperature, high-pressure plasma is violently unstable, and tries vigorously to break out of the containing fields.

Much has been learnt over the past 50 years on how to control a plasma, but controlled fusion still seems to be 20-30 years in the future. It is a difficult problem.
Quote
By the way, the plasma would be heated by pulsing the current at the resonant frequency of the fuel.
Fusion fuel is Hydrogen (typically a mixture of Deuterium & Tritium), which has been stripped of all its electrons to form a plasma.

What is resonating here? How do you calculate the resonant frequency of the plasma, and how would you excite it at this frequency?
 

Offline tnhfr1

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Re: Could this be a viable fusion reactor?
« Reply #7 on: 10/12/2015 20:03:19 »
In the video, there seems to be a variance in the temperature and therefor the ionization of the plasma judging by the color. The plasma seems to be hotter and more dense toward the center and I often observe pink opaque tornadoes at the tip pf the cathodes.
In order to create fusion, an area only large enough and dense enough has to be maintained. As long as more energy is created than lost, Lawson's Criterion would be satisfied.
This is still excluding any magnetic fields created by the plasma. A self organized structure (if created) should decrease heat loss through convection.
Sense the plasma in this system is not "confined" externally, it is free to self organize into a structure.
I would probably use a variable pulsed DC current for heating at a frequency of 61.4 MHz if the fuel where deuterium or a fraction there of.
 

Offline tnhfr1

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Re: Could this be a viable fusion reactor?
« Reply #8 on: 13/12/2015 03:50:58 »
Anyone???
 

Offline evan_au

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Re: Could this be a viable fusion reactor?
« Reply #9 on: 13/12/2015 21:16:31 »
Quote from: tnhfr1
A self organized structure
This is the problem - a plasma is self-disorganizing. It wriggles and writhes around vigorously, and tends to break out of whatever confinement you place it in.

You need continual high-speed measurement and adjustment of magnetic fields to overcome the innate tendency of the plasma to escape.
See: https://en.wikipedia.org/wiki/Magnetic_confinement_fusion#Magnetic_fusion_energy
Quote
variable pulsed DC current
How do you inject a DC current without using electrodes (which will be eroded and poison the plasma)?

Some of the promising experiments have used a ramping DC current, which can be produced by non-contact means. But as soon as the current reaches the maximum level (whatever that is), you need to reduce the current, and this causes containment to fail.
Quote
heating at a frequency of 61.4 MHz if the fuel were deuterium
How is the 61.4MHz calculated?
- Does this frequency depend on the strength of the magnetic field?
- What if the strength of the magnetic field is different at different points in the chamber?
- What would be the equivalent frequencies if the fuel contained tritium or protons (normal hydrogen nuclei)?
 

Offline tnhfr1

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Re: Could this be a viable fusion reactor?
« Reply #10 on: 14/12/2015 00:52:29 »
In this device, ions should begin to orbit the cathodes in an organized fashion.
Moving charged particles create a magnetic field and therefore organize.
Under the right conditions, I speculate a disc or torrid.
As the ions orbit the cathodes an equilibrium can be maintained so they are not colliding with the cathodes.
And if necessary, the electrodes could be consumable as there is a way of removing the impurities from the plasma.
61.4 MHz is (by one source) the nuclear resonance of deuterium though may or may not be the best frequency for this.

Check out euro-fusion org fusion spot-on-jet-operations maintaining-the-plasma heating-the-plasma

By pulsing the electric current at the right frequency will heat the plasma.
Collisions should impart heating to the tritium ions or a more complicated pulsing pattern may be employed.
The pulsed-field would never be so low as to allow the plasma to escape.


 

Online chiralSPO

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Re: Could this be a viable fusion reactor?
« Reply #11 on: 14/12/2015 01:16:30 »

61.4 MHz is (by one source) the nuclear resonance of deuterium though may or may not be the best frequency for this.


The "nuclear resonance of deuterium" is determined by the strength of the magnetic field that the deuterium is in a 9T magnetic field (very strong!) And this frequency has no bearing on the ability to inject energy into the plasma. It represents the frequency required to flip the spin of the deuterium nucleus from parallel to anti-parallel to the external magnetic field...
 

Offline tnhfr1

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Re: Could this be a viable fusion reactor?
« Reply #12 on: 14/12/2015 02:28:23 »
If the 400 kv used by iter where used in this device....
 

Offline Atomic-S

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Re: Could this be a viable fusion reactor?
« Reply #13 on: 14/12/2015 05:36:08 »
Methinks you would have better luck creating two beams of nuclei (deuterium or tritium) going in opposite directions and then slamming them together as in the Large Hadron Collider. Unfortunately, the amount of energy required to operate it would likely be far greater than the amount released by the fusion.
 

Offline tnhfr1

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Re: Could this be a viable fusion reactor?
« Reply #14 on: 14/12/2015 22:24:34 »
I think we are looking at this all wrong.
First, I would consider this device to behave like a particle trap.
My question is, could it be made to hold particles at high enough energy and density to sustain fusion?
There are a number of methods that could be employed to heat the plasma.
 

Offline evan_au

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Re: Could this be a viable fusion reactor?
« Reply #15 on: 15/12/2015 10:26:01 »
Quote
In this device, ions should begin to orbit the cathodes in an organized fashion.
In a plasma, there are two kinds of ions: + (eg deuterium nuclei) and - (electrons).

The + ions (nuclei) will be attracted in a straight line towards the cathode (- charge), where they will cancel the charge, and become atoms (not a plasma any more).

The - ions (electrons) will be attracted in a straight line towards the anode (+ charge), where they will cancel the charge, and flow through the metal anode into the power supply (not a plasma any more).
Quote
I would consider this device to behave like a particle trap
Applying a DC voltage will allow the ions to flow to the electrodes, and destroying the plasma. This is not a particle trap.

Quote
Under the right conditions, I speculate a disc or toroid.
You can get protons orbiting in an organised fashion, similar to the way the magnetron in your microwave organizes electrons; it would look something like a cyclotron. This avoids the flow of a DC current by applying a high-frequency AC field, and using a magnet to bend the electrons around in a circle.

But when nuclei are orbiting in an organized fashion, they do not collide with each other at high energy, which is a prerequisite for fusion.

You could accelerate the protons in two cyclotrons, and collide them, and this is what Atomic-S suggested.

Magnetic confinement fusion designs often have the ions spiraling around a magnetic field; so they don't escape at the "ends" of the magnetic field, they often create the magnetic field in a closed path (a spiraling toroid shape). By heating the plasma, they can get a tiny fraction of the nuclei to collide with sufficient force to initiate fusion, while retaining enough order in their motion to remain confined by the external magnetic field.

Quote
Moving charged particles create a magnetic field...
I agree.
Quote
...and therefore organize.
I disagree. A moving charge in a magnetic field will experience a force which is at right angles to the direction of motion, and at right angles to the applied magnetic field. So the instant you set up a magnetic field, the particles that originally created the magnetic field start to move so that the magnetic field is destroyed. It is self-disorganizing.

You can't generate a strong containing magnetic field from within the plasma, but you can apply an external ordered magnetic field, by using superconducting magnets, for example. As I understand it, the pressure of the plasma will soon find the weakest point in the magnetic field, and it will start to leak out at this point. The leakage causes the magnetic field at this point to become even weaker, allowing even more to escape.

This is why you need a closed-loop control system to keep the plasma contained.
 

Offline Thebox

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Re: Could this be a viable fusion reactor?
« Reply #16 on: 15/12/2015 10:37:03 »


This is why you need a closed-loop control system to keep the plasma contained.

Do you  mean like the doughnut design Tokamac ?
 

Offline Colin2B

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Re: Could this be a viable fusion reactor?
« Reply #17 on: 15/12/2015 15:14:56 »
This is why you need a closed-loop control system to keep the plasma contained.

Do you  mean like the doughnut design Tokamac ?

No, he means the electronics that control the containment field. Closed loop means there is feedback in the system rather than relying on manual control.
 

Offline tnhfr1

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Re: Could this be a viable fusion reactor?
« Reply #18 on: 15/12/2015 23:18:37 »
There are two cathodes (-) at the center. From a distance, they look like a point charge. As the (+) ions accelerate them, many pass between them and begin to orbit.

Is it possible that the positive ions concentrate more heavily around the negative cathodes creating a virtual anode therefore creating a shell of electrons around the plasma?

Wouldn't the orbit of the (+) ions around the (-) cathodes they should begin to orbit in the same direction for reasons to be explored later?

As charged particles orbit, they create a magnetic field. Yes there is an angular force applied to each ion so the actual path so should be a spiral as they orbit around cathodes creating a torrid (doughnut).

Isn't this is the same path that a particle takes in a tokamak?
 

Offline Atomic-S

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Re: Could this be a viable fusion reactor?
« Reply #19 on: 17/12/2015 03:44:34 »
I find this unclear. A diagram would help.
 

Offline tnhfr1

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Re: Could this be a viable fusion reactor?
« Reply #20 on: 17/12/2015 19:20:46 »
Do you mean the electrode configuration?
I do show it at 40 seconds into the video.
 

Offline tnhfr1

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Re: Could this be a viable fusion reactor?
« Reply #21 on: 02/02/2016 21:23:27 »
Can anyone explain what is happening in my vacuum chamber???
Add who should I talk to to verify my results?
 

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Re: Could this be a viable fusion reactor?
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