Back to Basics

[darkspeed]

Back to Basics

Grumpy, everyone:

Imagine you have a high voltage DC source  , two pieces same length copper cable, and you connect each one to the terminals - and +. You push the others ends together slowly, forming a spark gap, until the you see the spark.

What is the spark?

From which terminal the spark will form first?

What's a difference between the two side of the wave?

What's happening when we switch of the source when the spark formed?

The two conductors magnetically couple
Positive ions and negative electrons are pulled apart in the gap forming positive streamers and negative leaders
The gap ionizes
Arc
Do it fast enough that there is no ringing and you get a boundary condition and a shock-wave.

With a magnetic field and/or a shield/transport gas added it is a little different.

If you are talking just pure copper to copper arc you may get ringing through the arc.
If you heat the negative side and draw a slight vacuum you get a pretty good diode.

[sparks]

   Plasma is a weird animal.  It is formed into superatoms where the electrons can be found well beyond the spdf energy shells/orbitals chemists are so familiar with.  And atomic neuclei organized without the insulating layer of electrons found in gases.  Some plasma's display negative specific heat.  The higher the heat content the lower the temperature.  I believe this is because as the electrons are unbound from the neuclides they are free to form a current which intensifies as the electrons are accelerated by the energy input.  The faster this current about the ionized core the more insulationn it forms around the ionized atoms.  This is similar to a tornadoe where the circulating currents about the eye of the storm insulate the eye from barometric pressure.  The relative pressure between the insulated eye of the storm and the ambient field increases.  The viscous nature of air continues to draw molecules from the eye region into the circulation about it.  Sticky electron theory applies in a plasma.  So a region of space that appears empty is just the eye region of a huge coherent plasma.  Here and there in the cosmos the plasma cools down enough to form gases and other forms of matter.  I beleive that a highly polarized  efield can be used to cool the primordial background plasma enough to capture some 13 billion year old energy.  A spark gap before any hot current flows issues a cooling field. Kinetic energy of accelerated mass or waves (particle wave duality) converts into potential energy in the gap.  The gap becomes charged and when it shorts a higher than would be anticipated current flows.  eg electron cascading in vacuum tubes.  This radiant flow of energy from the ambient INTO the gap is not anymore complicated than touching an ice cube.  The energy flows from your fingers into the ice cube faster than it would if you were touching a warm glass of water.  I guarantee if you pull a field up to around 36kv it will start to get cold around it.  The ambient thermal energy then flows at an accelerated rate into the field where thermal energy is converted to electrical potential. There is a goodly amount of reflection as the energy surges towards the gap that radiates in the form of transverse emwaves but the real deal is the stuff that gets caught in the gap and the circuit designed to convert it and distribute the gap gain.

[Grumpy]

Back to Basics

Grumpy, everyone:

Imagine you have a high voltage DC source  , two pieces same length copper cable, and you connect each one to the terminals - and +. You push the others ends together slowly, forming a spark gap, until the you see the spark.

What is the spark?

photon emission

From which terminal the spark will form first?

both

if you have three gaps the outer gaps will spark first and then the middle gap

What's a difference between the two side of the wave?

one side is in a state of compression

the other side is in a state of rarefaction (expansion)

What's happening when we switch off the source when the spark formed?

The compression and rarefaction waves release the energy that caused them to compressed and expand.

[darkspeed]

These are my answers based on what i believe to be true, i could be wrong.

Is that the first moment?

As far as I understand it ,yes.

On which side we see the forming spark? What's happening in the meantime at the other side?

Assuming that Negative is always more powerful, and from my experience it is, I would say that the event would move negative to positive. I would assume that the other side was building a positive capacitance for a nanosecond.

Let's say we switch of the source before the spark could ionize the whole gap, but already formed out from a wire, what would we see in each end? Would be there two spark going in opposite direction, or one only?

The negative terminal would radiate breaking radiation and if the bias charge negative was maintained without oscillation a shock-wave exiting the event site at 90 deg. The Positive terminal would collect the incoming electrons and depending on the material and resistance would either conduct them or order them.

Let's say we insert an aluminum foil in the gap, copper wires at critical wide, spark would form,burn hole in the foil. How and why the hole was created?

Electrons would knock aluminum atoms out of state and move them to the opposing terminal or the plasma would modify the aluminum into aluminum oxide etc...

[forest]

Look here : http://www.energeticforum.com/renewable-energy/4628-teslas-mysterious-phantom-streams-3.html#post66134

positive streamers vs negative sparks

flow : negative -> positive

in normal arc oscillations ,back rush, alternations occur
when you suppress them who knows what occur ?