New 1.5 Gigavolts device

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Javier Lopez
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New 1.5 Gigavolts device

Post by Javier Lopez »

I where designing a device to inject some megajoules into a few cubic centimeters reactor. By chance I simulated a part of the circuit with the following surprise: the device would generate 1 gigaherz 1.5 gigavolts chirp (I used the russian S-300 2.2 megajoule z pinch capacitor bank data). Of course power could be increased, but there are following problems:
1. The device would be destroyed in about 6 nanoseconds that is below 600ns so it would be destroyed before generating the chirp, so the device size may be increased to a bigger one

2. Can this device boost fusion?

3. Can be concentrated this chirp to a 1cc cavity?

4. I would need a sutch that closes in a few nanoseconds and opens after 360ns but must support gigavolts

5. I supose that the gigavolts would ve converted directly to X or gamma rays

The teorical efficiency is very very high

I put here the simulation result
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Starfire
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Re: New 1.5 Gigavolts device

Post by Starfire »

This is fantasy Javier and not realistically practical - 1.5 Gv @ 1Ghz? - { better to use Lightning like the positive discharge in the pic. } There are no Ghz osc which work at 1Gv in existance.

Into a few cc - how to switch this small impedance and such fast rise time?

A UHV dry lab the size of an aircraft hanger would be required and would cost a fortune - to what end?
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Richard Hull
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Re: New 1.5 Gigavolts device

Post by Richard Hull »

John has it right. You'll never get a gigavolt and you will never work a power oscillator at that level in the gHz range. You are probably 100 years out from the highest level of technology today. Nature doesn't like big events that happen too fast and so she just doesn't allow it. The impedance of space (permittivity and permeability) limit things a bit.

Material science stands in the way of certain brissant events, as was noted.

Of course, one might start by trying to re-engineer some small volume of space.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
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Javier Lopez
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Re: New 1.5 Gigavolts device

Post by Javier Lopez »

I would agree but I have not read about what happens with breakdown voltages above 1 Gigaherz when the plates exceed L/4 where L is the wavelength: perhaps electrons have not enought time to break before field changes. I could redesign in order to increase the output frequency.

Also it is possible that so big electron accelerations could emit big amounts of X or perhaps Gamma rays so I would not see the gigavolts but lower RF and another emissions.

What would happens if I introduce >100Mjoule RF source in a 100cm length cilinder containing D-T?

Note: I am building a down scaled device, I do not know how to measure it but by the hell you can be sure I will build one!

Javier Lopez
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Re: New 1.5 Gigavolts device

Post by DaveC »

There is NO theoretical limitation against building a gigavolt potential source, other than the limitations of the environment in which you build it. After all, cosmic rays arrive at the outer limits of the earth's atmosphere with GV up to TV of energy.

The high energy physics folks are working towards TV energy accelerators. So it IS possible....in some ways.


But, as John and Richard have noted, in the atmosphere, you will need more space than anyone has.

Let's run through a couple numbers to get the idea. The maximum fields you can sustain in dry atmosphere at 760 Torr, are about 3 Megavolts/ meter. A wonderfully smooth metal electrode at 1 Gigavolt potential, would thus have to be at least 333 meters in RADIUS, or about 0.67 km in diameter.

Then, it would need to be a number of times its radius away from a ground plane, in order for this MINIMUM field intensity requirement to be met. At least 10X the radius would be necessary.

Soooo.. you would need a tower perhaps 6 - 7 km tall, with a nice smooth, very flat surface beneath for a few km in all directions. Looking like quite a skyscaper.

Now bear in mind, that no dust can be on anything, anywhere, or all of our size estimates will have to be increased very substantially... probably more that doubled.

Consider, also, that such a high potential electrode will be the world's largest electrostatic air filter, attracing dust out of the air for literally miles around. I doubt if one could actually ever get it clean, let alone keep it clean... but that's a mere detail.

The device we are sketching in here, begins to resemble something that dwarfs Nickola Tesla's power transmission fantasies.

One can only speculate on the climatic effects of such a gargantuan device.

Okay, ... you could put the whole thing in an enclosure and either pressurize it or evacuate it. Pressurizing would allow big reductions in overall size, since the breakdown voltage of compressed gases is much higher than air at 1 atm pressure. Perhaps an order of magnitude size reduction would be possible. (This, incidentally, is about what is achieved when air insulated HV power transmission lines are placed in compressed SF6 at a few atm pressure. - about a 10 fold size reduction.) There have been pressurized Van deGraaff generators that have reached 20 MV or more... so that's about 5% of the way. But a pressurized device almost 2000 feet tall?

Going to solid materials, the picture gets more still more complicated, since as the fields increase, the pathways for breakdown to follow also increase. A rule of thumb which derives from a good theoretical basis is that maximum breakdown stresses decrease approximately as the inverse logarithm of dimension. Thus something 10X larger has a about 2 - 3X lower breakdown strength. This is not a really good rule when sizes get huge, but at least points the way in smaller dimensions.

In semiconductors, it is possible to work with internal electric fields across junctions that are approaching the bond energies in the bulk material (which is the ultimate field intensity) - over distances of nm to even microns.

But you can't get usually within two orders of magnitude of this value when you are dealing with larger mm to cm size pieces.

Going to ultra high vacuum, we have to deal with field emission. The spontaneous eleronic emission from a highly charged surface. These fields are typically in the 100 to 1000 kV per mm range, which for a 1GV device would point to a surface of at least 1 meter radius.... with an atomically smooth surface. Any surface contamination, oxides and etc... and these numbers would have to be increased up to a 100 times or more.

At the interface of a solid material for supporting, insulating structures, the fields would have to at least 100 times lower than the 1MV /.mm values otherwise the insulators would fail instantly.

So.... building a GV device will be a serious challeng... probably a life long dedicated activity.

But then, perhaps you have some new ideas, that will do an "end run" around these obstacles. In which case, I say: "Go get em."..

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Re: New 1.5 Gigavolts device

Post by JohnCuthbert »

I'm afraid it gets worse when you look at the switching requirements. Since you are going to need something like a 100 metre sphere to avoid breakdown by field ionisation, it's not a bad guess that you will need a similar distance between the 2 electrodes in the switch. Even if the switch closed at the speed of light there's no way you get nanosecond rise times.
IIRC the formula for the capacitance of an isolated sphere is about 100pF /m (of radius)and thus stored energy of even a 1 metre sphere at 1GV is well into the MJ range.
Then scale that up for the 667M diameter ball on a tower. If I have the maths correct that's 33GJ of stored energy.
If you put that into a few cc of gas the temperature/ pressure will cause containment problems.
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Javier Lopez
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Re: New 1.5 Gigavolts device

Post by Javier Lopez »

If the device is little and the D-T is solid at near vacuum, I would switch the device inside the cavity. Of course breakdown will happens but do not worry because if very low pressure is present, a very little current would go because there is a limit because must wait for recombination of electrons. The device is impossible to contain that amount of energy because it will convert ina a plasma ball and will be detonated (like in the microdetonative fusion), so fusion must be happens before.

Actual device does not work properly so I am building a micro device of only 1 joule before making bigger ones.
I will use a fuse wire Switch calculated to fuse in 15nanoseconds. Do anybody has the formula to calculate wire fusing time?
Richard Hester
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Re: New 1.5 Gigavolts device

Post by Richard Hester »

How do you calculate that a fuse wire can clear in 15 nanoseconds? The wire vapor has to move pretty fast for that to happen.
Alex Aitken
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Re: New 1.5 Gigavolts device

Post by Alex Aitken »

I can't speak for anyone else, but the last time I used an electronics simulation package, it often produced garbage results. Like voltage multipliers that don't multiply, or ultra high frequency oscillations where no parasitic capacitors/inductors have been wired in...
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Javier Lopez
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Re: New 1.5 Gigavolts device

Post by Javier Lopez »

The fuse will clear at a I2t rate. I calculated to do that I would need a 4A^2*seg that is an standard 0.75A fuse (I believe), then I will block RF at a coil..
After fusing the wire it would convert in a plasma arc that can still conduct so it has to be absorb. (also I could use a fast plasma but cant do it know)

I am now working of lowering adverse effects due parasitics. Worse one is the serial ohm resitance. As result efficiency has lowering to 30-90%, others are ohm and some X rays

I have a name for the device: "Virtan" from virtual antenna
JohnCuthbert
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Re: New 1.5 Gigavolts device

Post by JohnCuthbert »

"
Actual device does not work properly so I am building a micro device of only 1 joule before making bigger ones.
I will use a fuse wire Switch calculated to fuse in 15nanoseconds. Do anybody has the formula to calculate wire fusing time?"
1 Joule won't melt any use wire to speak of and no fuse will act on a ns timesale.
For what it's worth you need to work out the energy required to vapourise a given length of the fuse (It doesn't matter what length you use) from the density, diameter and heats of fusion and vapourisation (the energy used in heating it generally isn't very large) . Then you work out what power that corresponds to for the time taken to "blow". Then you work out the current such that I^2 R ( for the length you took in the first place) gives that power.
It still won't work because, for the sort of timescale you are talking about, a fuse has a significant inductance so the bulk of the applied electricity is going into producing a magnetic field rather than melting metal.
It also won't work because even HRC fuses don't stop high currents (or at any rate, not quickly)
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Brian McDermott
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Re: New 1.5 Gigavolts device

Post by Brian McDermott »

Stepping back from the obvious issue of even getting 1GV, it should be noted that voltages that high are completely useless when it comes to producing fusion reactions. Fusion is done in the KeV range, 1 million times less energetic than what is being proposed here. The DT reaction's cross section peaks at about 150KeV, so why anybody would even want to go higher than that is beyond me. The D-D cross section peaks at about 2MeV, a nearly unobtainable voltage in its own right (at least at any reasonable physical scale and cost).

You want enough energy to make fusion happen, not to hit the atoms together so hard that they spall into a dozen different types of primordial subatomic goodies.
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Re: New 1.5 Gigavolts device

Post by Alex Aitken »

Thats a very good point Brian.
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Javier Lopez
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Re: New 1.5 Gigavolts device

Post by Javier Lopez »

Bad news:

After making really lots of simulations in order to design the first device and taking in account all the parasit involved I have seen that it is true that 80% energy transfer to the device can be done BUT the RF energy released would be very little: no more than 17% that is a good performance for a RF generator but not for fusion. I think the best is to convert the device as a part of the switch and release the whole energy in the switch: just in the same way that it is done at Sandia Z pinch but (it is important) designing the switch to break just when the capacitor bank is empty.
I think also that sandia z pinch switch could be broken during testings

Of course I will follow researching to develop new electromagnetic generators

Here are my simulations results.
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Javier Lopez
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Re: New 1.5 Gigavolts device

Post by Javier Lopez »

I have seen that increasing a little the volume I couls yield 35% efficiency and an energy density of 0.51 joule*second/cubic meter density for every capacitor joule .

I could reduce the output power but also frequency would be reduced. Perhaps the hard collisions and subparticle creation could heat the fusionants.
Do anybody know frequency function energy efficiency transfer of RF to plasma?

Well, its time to test
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Javier Lopez
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Re: New 1.5 Gigavolts device

Post by Javier Lopez »

I built the first Virtan. I had saddly to strugle its output frequency and output voltage in order to proper switch with commercial electronics device and to not destroy the scope. And here is the results:
Input voltage 3.51V, output voltage: 30V
output frequency: 50khz.
the limiting resistor were very hot because they reached the maximum power but I increased the voltage and current:

Input voltage 10V, output voltage: 60V
output frequency: 50khz

At the second test the two 30W resistors where toasted and I had to stop the tests, so test result are not confident.

As result: the output voltage was lower than designed, but it was expected due long and thin wires introduces too much resitance and inductance loses and the worse of all was the switch, but at least the device works!

The second photo is the simulation plot.
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JohnCuthbert
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Re: New 1.5 Gigavolts device

Post by JohnCuthbert »

I think I must have missed something. What is this device and what is it meant to do?
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Javier Lopez
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Re: New 1.5 Gigavolts device

Post by Javier Lopez »

The device is a Shirp frequency generator that compress the waveform. It is designed to be a powerful and efficient RF plasma heater.
Actual device parameters are:
Input: 1.5Vp (after limiting resistor) 1250hz
Output: 30Vp 50kHz

As long as no linear component inside I expect that the device can be scaled to much higher frequency and voltage

P.D: I suspect that power losses are due 3/4 part of power is delivered to the atmosphere as a standard RF waveform
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Re: New 1.5 Gigavolts device

Post by Nick »

How do you plan on transmitting the energy. At 1ghz your waveguide
would be wr975 which approx. 10 inches by 5 inches and at that high a
potential even 1000 psi of sulfur hexafluride wouldn't insulate against a
cross guide arc not to mention a cross flange arc. Oh also at 1 ghz if you
used anything besides waveguide the attenuation would be a killer.
Altought you could use transmision line but the largest size made is
around 8 inches and flash over in air would be 33,333 inches at d.c. in
pure gas atmosphere and not 1ghz. The ionazation brake down at that
frequency is much worse do to heating of the water molecules in the gas.
Although in theory I emphasize in theroy you could recalculate a higher
impedence transmission line with a massive inner diameter sheild and a
small outter center conductor and insulate it with dueterium dioxide which
is almost impossible to get and very corrosive not to mention extremly
toxic. Also how would you plan on coupling the power to the fusor.
Javier Lopez wrote:
> The device is a Shirp frequency generator that compress the waveform.
It is designed to be a powerful and efficient RF plasma heater.
> Actual device parameters are:
> Input: 1.5Vp (after limiting resistor) 1250hz
> Output: 30Vp 50kHz
>
> As long as no linear component inside I expect that the device can be
scaled to much higher frequency and voltage
>
> P.D: I suspect that power losses are due 3/4 part of power is delivered
to the atmosphere as a standard RF waveform
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