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Updated: 2023-07-18 10:34:09 + 4

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shwetha729 2023-07-18 10:34:11 -04:00
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The voltage and current relationship when a spark gap's gap is increased is as follows:
**The voltage and current relationship when a spark gap's gap is increased is as follows:**
Voltage: The voltage required to initiate a spark across the gap increases
as the gap widens. This is because the air in the gap has to be ionized
@ -32,15 +32,11 @@ gas that is present in the gap.
---
#1 rule, It is not deterministic.
Every spark gap is unique at some level. There is a distribution curve that can be exploited, in terms of multiple sampling and ratiometric sampling.
Both amplitude and time can be exploited.
the uniqueness can be measured, but not anticipated prior to the event.
and you can have more than one spark gap as well, but one current coupling them all together, i think this would have a tighter bell curve via synchronous, similarity induced averaging. the hot spark get damped by the colder ones, and the cold ones get sped up by the hot ones (think faster)
- #1 rule, It is not deterministic.
- Every spark gap is unique at some level. There is a distribution curve that can be exploited, in terms of multiple sampling and ratiometric sampling.
- Both amplitude and time can be exploited.
- the uniqueness can be measured, but not anticipated prior to the event.
- and you can have more than one spark gap as well, but one current coupling them all together, i think this would have a tighter bell curve via synchronous, similarity induced averaging. the hot spark get damped by the colder ones, and the cold ones get sped up by the hot ones (think faster)
---
The discharge concept becomes simpler if instead of thinking about the electric field between the electrodes which is the driver for the discharge process. Of course the shape and distance between electrodes determine the electric field, but the the electrons are only driven by the electric field. Putting in the geometry at this point only confuses the issues.
@ -52,11 +48,16 @@ What determines the probability of an electron colliding with a neutral molecule
1) the electron has to have energy greater than the ionization potential of the particular type of gas molecule 
2) The probability of a electron-molecule collision. This probability is very roughly the area of the molecule (cross-section) and the number density of the molecule in the gas times the path length between the electrodes. Pc ~ A x Nd x L. More commonly this is expressed as a distance = mean free path (MFP) for the electron molecule problem.  If the MFP is shorter than the distance between electrode there should be a ionizing collision. If the MFP is much smaller than the inter-electrode spacing there will be many collisions.
Now, if the energy acquired while traveling one MFP is greater than the ionization potential of the gas, then the electrons ejected from the ionized gas can, themselves can gain enough energy to ionized even more gas molecules. Anotherwords, we have self-sustaining discharge highly dependent on the inter-electrode voltage, the gas pressure and the gas type.
Now, if the energy acquired while traveling one MFP is greater than the ionization potential of the gas, then the electrons ejected from the ionized gas can, themselves can gain enough energy to ionized even more gas molecules. In other words, we have self-sustaining discharge highly dependent on the inter-electrode voltage, the gas pressure and the gas type.
How do we get the first electron that we need to trigger the discharge?  It can come from a cosmic ray, a radioactive element in the chamber, a UV light source. Also, a high enough voltage across the electrodes (producing a high electric field) can cause: 1) electrons to be torn directly from the molecules or electrons can be torn away from the metal electrodes (field emission).  
How do we get the first electron that we need to trigger the discharge? 
It can come from a cosmic ray, a radioactive element in the chamber, a UV light source. Also, a high enough voltage across the electrodes (producing a high electric field) can cause:
1) electrons to be torn directly from the molecules or
2) electrons can be torn away from the metal electrodes (field emission).  
This is the qualitative basics. Real world is a bit more complicated, but these concepts might give you a qualitative understanding of the principles involved. Certainly, look at the Paschens Law information.
BTW  If an electrode has a sharp point, like a needle, that geometry results if a high electric field near the point. That's how field emission electron sources are made.  If you heat the electrode hot enough, the electrons in the metal can get hot enough to be ejected from the metal; i.e., thermionic electron sources.
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