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Author Topic: Standing wave in Xenon gas  (Read 34459 times)
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Just thought this was cool..

I tuned a Xenon tube to its resonant frequency and pulse width to establish a standing wave in the gas



   

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Now that is cool  ;D

So now we know what a standing wave looks like, i don't know if it's the camera but the nodes appear tear drop shaped and seems more dense to the right.

I have seen nodes on a copper wire before, Some time ago i was playing with Lifter asymmetric capacitors and could clearly see the node's glowing in the dark, this wasn't at resonance and only one end of the copper wire was connected, to replicate use the thinnest copper wire possible(i used magnet wire with insulation and pulsed dc 30kv from LOPTX) an aluminum skirt 3.5cm below as in standard lifter configuration, and it's possible to see the corona discharge at the nodes, i wonder if you could tune to see the standing wave in copper, just adjust the skirt air gap to your voltage to induce corona discharge.

The thing i don't understand is that the nodes are so close together at such low frequency and don't seem to relate to the wavelength of the frequency being used.
   
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Peterae, I crossed this point coming down from an output test at 500khz. I think I was in the 300khz range but like an idiot I forgot to note the exact frequency. I will have to go back and find it again.
Resonance is a function of frequency at a pulse width, if you cant be at the natural frequency you can sometimes resonate it by adjusting the pulsewidth.
The power level has to be really low as to not wash out the resonant points. I crossed one point where there were only five elongated balls of light in the tube. when you are 180deg off a resonant point the fine thread turns into a purple fog in the tube.

I am facinated by asymmetrical lifters but I have never built one.... yet  ;D
   

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It's so much easier when you can see what's going on.

300kHz has a wavelength of almost a 1000 meters, but i guess that's in air, so how on earth can the nodes be a few mm apart.

Now if the nodes were 5mm apart that equates to 59Ghz resonant Freq if this online calculator is to be believed.
   
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Hi,
I've a couple of 20KW (supposedly) xenon tubes encased in quartz.
You mentioned low power levels so are you feeding them with half wave dc at several hundred volts from a line transformer or equivalent?
Are yours at 1 atmosphere pressure or lower?
I recon we have seen striations before in discharge tubes but the pressure has to be near perfect vacuum for this and xenon tubes generally have far higher pressures than that.
If the nodes relate to sound resonance in the tubes then the velocity of sound in xenon is required. Maybe a calculation will prove/disprove this interesting effect as the cause.

Steve.
   
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This is a 6" Xenon gas / quartz body strobe bulb from and audio modulated strobe light.
It originally had a trigger wire wound around the outside but i removed it.
It is great for testing!

I cant explain why the node spacing is so low. You can get standing waves at harmonics..

Could be a harmonic of the main RF

2ghz would be 6 inches - maybe it is the natural RF of the gas volume itself???

« Last Edit: 2010-03-18, 16:49:20 by darkspeed »
   

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well i am glad i am not the only one that doesn't understand the node spacing, on my 30khz lifter coil i was getting approx 1cm spacing and this was in air, and i was sending dc pulses down the wire, so i would have expected the distance to be equal to the speed the pulse traveled in between the pulses, but 1 cm seems tooo slow
   
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There is more.

Keep playing in that direction.
   
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Here is another one

you cant see it but there is an almost invisable second wave 180deg to the bright one and the repell each other

   
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This one is a little faster.

   
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This one is a little faster.



I replicated your results, with one little longer xenon filled tube. (electrodes 320 mm apart). These "balls", which for me at higher power level look like cones, are very interesting. Are these cone, ball shaped standing waves real transverse waves?

In my experiment I started to drive the tube with low frequency as possible, wrote down every single transverse wave node appearing until I reached my driving circuit, supply limitations around 300khz.  Transverse standing waves appears at many frequency, as I go higher, higher harmonics coming, with more nodes.  They look like normal transverse waves, definitely with higher amplitude, as in resonances points we should see, like in attached picture.


But these ball, cone shaped waves could appear with normal transverse standing waves together. How is that possible? How, and why they could form cone shape? First time I thought they are just destructive interferences. Interestingly, they appear first at around 4700hz.

At some frequency when the transverse wave nodes touching the glass of the tube, I hear a scratching sound, something like when a spinning grinder head touch a glass.The nodes sometimes start to move around the glass, like a rotor of a motor, when I hear the sound.  Did you noticed something like that?


Ps.: sorry for the bad picture quality, these are snapshots from videos
« Last Edit: 2010-05-02, 23:50:04 by Chef »
   
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Good job Chef!

The teardrop is a directional bias indicating the direction it wants to rotate ( L or R with at exact resonance being dead center still with the teardrop turning into a ball shape )
   

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is the wave flat or spiral?
   
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In what plane do you think they rotate, and why? Magnetic field around a plasma is like around a wire, so 90 degrees to the length of the tube. Poynt pointed out to me, for a rotation we should have an another magnetic field. Anyway I believe the plasma rotate, when I playing with tuning, before I reach the the exact frequency to form whole-number nodes, it could be clearly recognized one side of the plasma trying to rotate CW, and the other CCW, and when I reach the balance,no "stress" at all, the whole wave with all the nodes are flat, in one plane. At some point, I could make the nodes spinning around the glass tube, without a parallel magnetic field, when the nodes touch the glass. I will edit the videos, and upload some to show it.

These ball, teardrop waves must be simple longitudinal ones. Clearly there are  rarefaction and compression along the wave lines, however I don't clearly understand right now the teardrop shape, and the cause of it. I found in Russian literature they mention that teardrop shape.

"Furthermore, when quantum physicists have studied the “electrons ” of the atom, they have observed that they are not actually “points ” at all, but rather form smooth, teardrop-shaped “clouds ” where the narrowest ends of the “drops ” converge upon a very tiny point in the center "

Depending on the frequency and power level, I could produce them toward + and - pole too, and with some tuning they appear with transverse wave together.
« Last Edit: 2010-05-05, 11:37:20 by Chef »
   
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is the wave flat or spiral?

Flat. However when you add a parallel magnetic field to tube length, the wave turn into a spiral.
   

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Cool work Chef, thanks for sharing, looks fascinating.
   
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Here is a mentioned spinning video. The quality is really bad, but I hope it come through.  :(

[youtube]http://www.youtube.com/watch?v=TtMg9_-OfaA[/youtube]


The nodes spinning around, as they touch the glass tube, and I can hear the scratching sound too. I think there is a rotation in the plasma when there are no nodes at all, without any parallel magnetic field. I talked about that with Poynt99, and he think, there should be no rotation at all, without an other magnetic field.

Anyone, any idea, why the nodes spinning like that?
   

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the plasma will have it's own magnetic field and this will interact with any other field, even earth field

is the flat wave always the same orientation to earth?

Teardrop may indicate different velocity for cw and ccw wave...  ;D
   
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the plasma will have it's own magnetic field and this will interact with any other field, even earth field

is the flat wave always the same orientation to earth?

Teardrop may indicate different velocity for cw and ccw wave...  ;D

Yes. It have own magnetic field. In russian plasma literature they mention cycloid movement of the ions in the plasma at critical current densities, without an added magnetic field.

The flat standing  waves doesn't have same orientation to the earth.



   
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sinusoid with saturation
   
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The thought crosses my mind:
As cool as it looks in a picture, has anyone measured input-output power levels for overunity while in resonance?

--Lee
« Last Edit: 2010-07-14, 21:20:39 by the_big_m_in_ok »
   
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Fascinating stuff.  The standing waves have to be acoustic in nature.  You know when the gas transforms from ordinary gas to plasma that it heats up.  Therefore this creates a small acoustic pressure wave in the gas from the expanding heated plasma.  These mechanical pressure waves are periodic due to the periodic excitation provided by the high voltage AC power source.

Every time you set up a standing wave, you are at some harmonic of a fundamental frequency.  You never are looking at the fundamental acoustic resonant frequency of the air cavity, you are looking at a harmonic on the resonant frequency that is always (N x Resonant_Frequency) where N = 2, 3, 4...  It's almost like the playing of a flute in terms of the setting up of the standing waves.

The glowing teardrops are most likely at the pressure nodes in the acoustic wave.  There the gas molecules can stay bunched together and "get a good glow on" while the AC current flows through the tube.  The gas/plasma molecules don't move too much at the nodes.  Between the pressure nodes the pressure is at it's AC peak, and hence the gas/plasma molecules are moving back and forth very rapidly and you can't see the glow that easily but it still must be there.

I can't explain the teardrop shape.

As far as any possible over-unity stuff goes, time to take a step back and really see what you are looking at.  These tubes for all practical intents an purposes are like resistors.  You pump AC power into them and they get hot and give off light.  They turn electrical power into heat power and light power and even a bit of sound power.  The question about possible over-unity is misplaced in this case.

Anyway, just my thoughts but I am no expert here.

MileHigh
   
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Hi
If we assume that at certain frequencies there exists stationary pockets of high and lower pressure then there must be as a result areas of differing conductivity. If these areas of conductivity are high then does the Crookes dark space enter the equasion?
Thoughts.
   

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If the energy in each node is extracted using some means and the anti node is used as a reference point for that energy would you not have a DC output, question is how much power would you get.
   
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Any ideas on how it could be considered a standing wave without a reflected wave?
   
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