# Plasma, what is its density?

Will the plasma have a density > "X" or density < "X"? Could you give me some examples with numerical values?

Thanks

We have a fluid (gas or liquid) with a density "X". And we apply a voltage to convert the fluid plasma.

Will the plasma have a density > "X" or density < "X"? Could you give me some examples with numerical values?

Thanks

Will the plasma have a density > "X" or density < "X"? Could you give me some examples with numerical values?

Thanks

- Hello Toni,

Well, for getting to the plasma state you have to increase the temperature, first to reach a gas and the to ionize the gas, so the density is going to be less than X. What it's density is will depend on the degree to which it is ionized (check Saha's equation). Usually it is considered fully ionized, and then you have two fluids (electrons and ions), each with it's own density.

Typically, for plasmas under a given potential, its density can be described by the Boltzmann relation: http://en.wikipedia.org/wiki/Boltzmann_relation

Cheers - It depends on how you define 'density.' If it is mass density then there will be no change, but if it is particle density, then the overall density will increase mainly because you will increase the number of total individual particles. The reall issue here is what is the type of gas, and the degree of ionization. For a heavier gas (e.g. neon) which has 10 electrons per atom, you could feasibly have ten times the electron density compared to the ion density. Along those lines, if the voltage is weak, only a handful of atoms may be ionized, so the neutral density would drop, but the ion and electron densities would increase, but still be less than the neutral density.
- Interesting question with a complex answer. Yes, particle density will increase once charge separation is achieved. However, the electrons and ions will immediately begin to electromagnetically self-organize into Birkeland filaments, in which electrons and ions are kept separate by "double layers" (see Hannes Alfven and Juergens). Mass density will then vary in striations in a given volume of space. Charged particle density will even out as electromagnetic boundaries stabilize in the filaments, which act like wires carrying a current. Refer to the filaments in a lab "plasma sphere" for a visual of this.
- Thank you very much for your answers!. ResearchGate is a great page thanks to people like you. thank you very much. For example, my primary idea has been ... a light bulb with two terminals. It forms an electric arc (10 kV-20kV). Inside the bulb there will be a noble gas. If the density of the gas is, for example, 1 ... when electricity excites the gas, the density will D> 1? D <1? and if the volume is 1, when electricity excites the gas, V> 1? V <1? Obviously, if V> 1, the pressure will be implemented ... and if the pressure is implemented, what do you think about making a light bulb of aluminum dust? Aluminum dust glass can withstand a lot of pressure of the ionized gas. What do you think about this? PS: My native language is Spanish, sorry for my bad expressions in English :)
- I'm not quite sure about the aluminum dust aspect of your design, but from a physics perspective, the ionization will increase the pressure (in a large-scale, global sense - I am not really talking about plasma dynamics here). The total pressure will be equal to the sum of the partial pressures of the neutrals, the electrons, and the various ions. They can (and in the short term, probably will) all have different temperatures. It is really a simple gas law problem. The pressure only depends on the number density times the pressure, so if you are increasing the total number density, the pressure will go up.
- http://www.youtube.com/watch?v=RnUszxx2pYc

The ALON (aluminum dust glass) is more resistant than normal glass. Maybe if i get a significant volume of plasma at high pressure, i can get a great light. Something like a very strong fluorescence.

Anyway, Daniel, you say it would be a simple calculation of pressure, right? In plasma data I am lost.

Suppose 30 grams of Nitrogen, for example, (23.98 liters approx in normal conditions), and apply a ionization energy 1402.3 kJ / mol (the 1 st ionization energy). How I can I calculate the volume of N2 plasma state? And changes in the density? What formulas and / or theories could be applied to obtain the result?

Thank you very much, this support is vital for me! - well, you ask question about the density or plasma density.... very simple in plasma physics, density and temperature are basic parameters of Plasma (Fourth state of matter) but upto my knowledge, mostly researcher used the noble gas which have the last shell filled,

within Plasma, it is already defined those mentioned parameters ranges. if range is less than the defined ranges, then you will not say it is plasma , it will be called normal ionized gas but will never be considered Plasma.

Generally, plasma density is actually the electron density or some time called electron plasma density.

you can study all about Density or Plasma Density online on different websites,

after seeing you will be well aware about answer of your question. - Plasma density strongly dependent on the degree of ionization of gas. Also depends on collision mean free path of electron - atom impact, voltage which are applying for discharge is another fact . Since volume of chamber is not changing so no. Of particles in unit volume is increased (atoms, ions electrons).it means ,the mass density is not changed. Plasma density is not combined density of species but it is density of any species (either electron or ion). Therefore plasma density is less than gas density( in contents of ion) and may be greater ( for electron) if temp is very high or multiple ionization takes place.
- If it is fully ionized it will have the density X. If it is partially ionized, it will have a density
- The original question from Toni Rodriguez concerned a "light bulb with two terminals" filled with a noble gas. That would be a neon lamp or neon tube. There are many design parameters available for these online, depending on purpose (illumination, relaxation oscillator, etc.).
- It exists 2 densities: kg/m3 in SI units

Particles/m3, that is given using Avogadro number

Also it could be used ionized particles/m3 that is the usual number used in partially ionized plasmas that is the particles/m3 multiplied by a factor between 0 and 1 that is the percentage of ionization as said Mangilal

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Daniel R Mccarthy· Southeastern Louisiana University