Theory, experiments and calculations related the physics of plasmas, i.e., matter constituted by ionized atoms.

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Simulating electrical sublimation of aluminium foil

When i apply high voltage (through a capacitor bank) across an aluminium foil, it gets converted into plasma. I want to simulate this process and study the properties of the plasma produced ...
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54 views

Why do noble gases stabilize plasma discharges?

In the plasma literature, noble gases—usually helium or argon—are frequently said to 'stabilize' plasmas. For instance in this patent, the inventor states that the plasma can be stabilized "by adding ...
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467 views

Camp Fire Crackle

I was sitting around the camp fire and there was a periodic sound of cracking and pieces of the burning wood flew off. My question is what is the mechanism for the cracking of the wood? I was thinking ...
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32 views

Radiofrequency attenuation in cold plasma

The missile plume can be considered a cold plasma. If a radio signal passes across the plume it's attenuated. Obviously the attenuation depends on the frequency of the signal. Where can I find some ...
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51 views

metastable energy levels

can someone give me a good definition of "metastable energy levels" in a helium plasma (glow discharge). Am I right when I say : "by adding some neon in my helium plasma, I will obtain a molecular ...
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203 views

Effect of electric field of plasma sheaths

How will an electric fields affect the formation of plasma sheaths?
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295 views

Is a plasma a distinct phase of matter?

Long ago I learned that a plasma was a distinct state of matter after solid, liquid and gas, and also that it was achieved by imparting heat to a the matter. But most references describe a plasma as ...
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29 views

What happens to the electrons that escape an atom when matter is converted to a plasma state?

Lets say we have a device that generates plasma fields; if this device creates plasma by heating a gas, where do the electrons that escaped the "orbits" of the atom go? Would the electron physically ...
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37 views

What will happen if we will be able to produce a quark-gluon plasma and the we cool it down?

Lets assume that we can produce a quark-gluon plasma and then we try to cool it down, what will happen to it ?
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65 views

Does the 1-D poisson's equation have monotonic potentials if $\rho=\rho(\phi(z))$?

I am solving the 1-D poisson equation: $$\frac{d^2 \phi}{dz^2}=-4\pi\rho(\phi)$$ with the additional requirement that $\rho(\phi(z=0))=0$. If I start by multiplying each side by $\frac{d\phi}{d z}$ ...
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Using a Plasma Globe to generate real random numbers

I have been thinking how to easily generate real random numbers when I cam across the small USB-powered Plasma globe. My idea would be to place it in front of an light sensor and read the sensor's ...
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8k views

What's the difference between gas and plasma?

A friend stated that stars are hot balls of gas, however we know that technically stars are plasma. Is his statement entirely incorrect? Can a plasma be considered a form of gas or should be referred ...
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45 views

Convective derivative of oscillating fluid with bulk motion?

I have a fluid $u$, which comprises a zeroth order constant motion $u_0$ as well as a first order oscillatory motion $u_1$. The convective derivative is $$\frac{\partial u}{\partial t} ...
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68 views

Can be the ionosphere described as an elecro-magnetic field?

I read that the ionosphere can be defined as plasma. it has its plasma frequency it has its Debye length it is overall neutral As it is overall neutral it does not produce any electric field. ...
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64 views

Geiger meter affected by plasma lamp

Whilst testing a geiger meter I took it near a plasma globe (the type sold in party/toy stores). The meter showed 0.13 mcSv/h. Then I turned the lamp on and low and behold the meter jumped to 0.89 ...
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87 views

Characteristic waves in a plasma

What does "characteristic wave" mean in the context of plasma waves? For example, when propagating parallel to the plasma magnetic field, the characteristic wave is circularly polarized. Does this ...
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42 views

Minimum number of interacting particles to form a plasma

After reading this question What is the minimum number of electrons necessary to propagate a plasmon? I began to wonder what is the minimum number of particles needed to have a plasma? I figure that ...
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101 views

Why do many books say quasineutrality is needed for a plasma to exist?

Many books on plasma physics (Chen, Goldston, Lieberman) say that quasineutrality must be satisfied for the matter in question to be a plasma. Yet, we know that non-neutral plasmas exist. So why do so ...
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173 views

$E\times B$ drift of a single particle in vacuum with unifiorm $E$ and $B$

The force on a charged particle in electric field $E$ and magnetic field $B$ is given by: \begin{equation} m \dot{v} = q ( E + v \times B) \end{equation} Then, the $E \times B$ drift velocity $v_E$ ...
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812 views

Can plasma turn back into gas, solid, or liquid?

I wanted to know if, since basic chemistry teaches you that states of matter can be changed, I was wondering particularly about plasma. I know that virtually all of the Sun is plasma, so I was ...
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350 views

Would an octahedral magnet work as a magnetic bottle?

First, let me see if I understand all this: Charged particles are curved by magnetic fields, so if the magnetic field is strong enough, the particles "follow" the magnetic field lines, in N or S ...
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50 views

Why is the collision term negative in the equation of motion for a fluid of electrons in a plasma?

The fluid equation of motion for electrons in a cold plasma is \begin{equation} m_en_e\frac{d\textbf{v}}{dt} = -en_e(\textbf{E}+\textbf{v}\times \textbf{B}) - m_en_e\nu\textbf{v} \end{equation} where ...
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Can Gases conduct Electricity?

Liquid electrolytes ionize and hence a current can pass through them. So if a gas can ionize, can it conduct electricity too? If so, what are a few such gases?
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Is there a phase transition between a gas and plasma?

Does a phase transition occur as a gas is heated to create a plasma? If so, is this a first or second order phase transition? Also, does the presence of a phase transition depend on the pressure or ...
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407 views

Why is lightning considered a plasma?

I was wondering why a lightning bolt is coined as "plasma", or a "spark" from an electrical wire/device is as well, yet flares, molten lava, and burning buildings are not(flares are pyrotechnic, ...
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118 views

Max temperature that can be obtained from radiation source when nonlinear interaction with matter is important?

Using a black body radiation as furnace it is usually said that the max achievable $T$ is limited to the T of the source. So a source of 3000K can not be used to heat a body above 3000K. A long ...
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3k views

Where on Earth can you find plasma?

Ok, so not that 'where on earth', like literally - 'Where on Earth'. Where on Earth, can you find matter in the 4th state, i.e. the plasma state?
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Plasma Stability

Plasma consists of positive(ions) and negative(electrons) charges. Ions repel each other, so do the electrons, in the mean time ions attract electrons and vice versa, what will be the net result? Does ...
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277 views

Could ball lightening be a form of plasma?

With regard to the recent arXiv article: J. D. Shelton, Eddy Current Model of Ball Lightening http://arxiv.org/abs/1102.1224 I wonder if this is a reasonable explanation of ball lightening, or if ...
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Transverse Magnetic (TM) and Transverse Electric (TE) modes

I'm reading and working my way through "Plasmonics Fundamentals" by Stefan Maier and I've come across a step in the workings that I'm struggling to understand when working out the electromagnetic ...
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433 views

How to tell theoretically whether an electron behaves as wave or particle

I have seen many questions on SE on the dual nature of electrons behaving in certain circumstances as particles and as waves in some other circumstance. There is one thing I couldn't get a clear ...
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77 views

plasma frequency in non-neutral plasma

Is it possible to see the oscillations with plasma frequency in a gas of particles of the same charge (not mixture of positive and negative charges)?
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Is it practical to slow down a plasma to with a spiral confinment to inrease direct plasma converter efficiency?

Instead of using tokomak/torus shaped tubing to confine plasma and slow it down to "useable" speeds. Is it practical to slow down plasma (with a magnetic field) over a long path using a spiral shaped ...
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51 views

What state is fire? Solid, Liquid or Gas or Plasma? [duplicate]

What state is fire? Solid, Liquid or Gas or Plasma? I was just roaming around when this question popped out of my mind. In what state is FIRE?
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Is fire plasma?

Is Fire a Plasma? If not, what is it then? If yes why, don't we teach kids this basic example? UPDATE: I probably meant a regular commonplace fire of the usual temperature. That should simplify ...
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93 views

Jupiter radiation belt: where >MeV particles comes from?

When I read some discussion about exploration of Jupiter moons, or possibility of life there, a common argument is high dose of radiation in Jupiter's radiation belt (several orders of magnitude ...
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137 views

Could I use an electron gun to make plasma?

Could I ionize a gas using an electron gun and knock off electrons in the gas to make plasma?
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212 views

What is electron density and its unit in plasma physics?

I can not find (through Google search engine) that what means electron density and what is its unit? and what is there relation between electron density and electrical conductivity?
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199 views

Why doesn't a neon sign seem that hot?

I heard that neon signs contain plasma, why aren't they hot? is it because the electrons and ions do not hit the lamp's wall? Is it because it is non thermal plasma and electrons and ions are not in ...
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43 views

Under what conditions is it possible to ionize atoms using an electron gun?

Using the electron bombardment method, if I wanted to ionize, for example, Xenon gas electrons with an electron gun, under what conditions is it possible to do so? (Heat, pressure?)
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Does Fire Conduct Electricity? Why?

Recently, I have stumbled upon a YouTube video by Veritasium describing the conductivity of fire. My question is: how exactly does fire conduct electricity? I am a high school student; therefore ...
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Intensive radiative heat transfer in very hot gas ( >5000K, gas core nuclear reactor related )

The question: At temperatures above ~5000K are not stable any solid or liquid materials or even more complex molecules (such as fullerenes and Polycyclic aromatic hydrocarbons) which emit/absorb ...
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227 views

Apart from Alfvenic turbulence, what is the most important unsolved problems in plasma physics? [closed]

Apart from Alfvénic turbulence, what is the most important unsolved problems in plasma physics? Is there a review article describing some important unsolved problems in plasma physics, I repeat, ...
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68 views

Plasma Propulsion system - Maximum Velocity [closed]

What is the maximum velocity that can be achieved using plasma propulsion if we could make a propulsion system as powerful as lightning ?
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132 views

simple MHD simulation code for (self) education and play with [closed]

I would like some super simple computational code for solving magnetohydrodynamics problems. High accuracy nor performance is not my concern. I wan't it just to visually explore qualitative behavior ...
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2answers
197 views

Is NaCl vapour plasma?

Yesterday I asked a question at Chemistry SE, which is if the molten NaCl molecules have enough energy to break into free moving ions, won't be the Na Cl vapor contain free moving ions? So, I've got ...
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55 views

Does phase lead or lag in a plasma?

Plasmas have an index of refraction less than 1. So say you sent one beam of light through a plasma and another one along a path just as long but in free space. Is the plasma beam's phase lead or lag ...
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92 views

Astronomical-wavelength radio (AWR) transmissions between cosmic plasmas?

My son asked me if electromagnetic waves longer than radio exist. I told him that even though physics permits such waves, there are no antennas long enough to radiate or detect them. However, on ...
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Voyager 1 cosmic ray strips

In the last months Voyager 1 has experienced a dramatic drop in the cosmic ray radiation, which was been exceptionally uniform for the last 10 years, except for the past july 28 and august 14 events, ...