Capacitor dielectric question?

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    Capacitor Dielectric
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Discussion Overview

The discussion revolves around the behavior of voltage in a capacitor when the dielectric material is an ionized gas. Participants explore the implications of using an ionized gas as a dielectric, including its physical properties and effects on capacitor performance.

Discussion Character

  • Exploratory, Debate/contested, Technical explanation

Main Points Raised

  • One participant questions how the voltage on a capacitor varies with an ionized gas as the dielectric.
  • Another participant suggests that the ionized gas will experience a force from the electric field, potentially causing displacement, similar to an ion chamber, and notes the importance of considering recombination and neutralization at the electrodes.
  • A different participant asserts that an ionized gas is unsuitable as a dielectric because it behaves as a conductor, leading to significant losses, and expresses uncertainty about this perspective.
  • A subsequent reply agrees with the assertion that ionization leads to current flow, referencing the operation of gaseous arrestors as an example.

Areas of Agreement / Disagreement

Participants express differing views on the suitability of ionized gas as a dielectric, with some arguing it is inappropriate due to its conductive nature, while others explore its behavior under electric fields. The discussion remains unresolved regarding the overall viability of ionized gas in this context.

Contextual Notes

Participants highlight the need to consider factors such as ionization, current flow, and the behavior of gases under electric fields, but do not reach a consensus on the implications for capacitor design.

trot
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How does the voltage on a capacitor vary if the dielectric is an ionised gas?
 
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This is relevant to my interests too. I want to understand this too. I can say that the ionized gas will have a force acting on it from the electric field which can cause position displacement like in an ion chamber. Because of that, you would have to consider things like recombination and neutralization at the capacitor's electrodes.
 
Last edited:
trot said:
How does the voltage on a capacitor vary if the dielectric is an ionised gas?
I would say an ionized gas is not suitable as a dielectric. It's a conductor, making for a very lossy dielectric. But maybe I'm missing something here?
 
NascentOxygen said:
I would say an ionized gas is not suitable as a dielectric. It's a conductor, making for a very lossy dielectric. But maybe I'm missing something here?

agreed

as soon as the gas ionises it will pass a current. This is the principle of how gaseous arrestors work. 2 metal plates with a gas in between, when the voltage gets high enough to ionise the gas, it will provide a path for the current to flow

Dave
 

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