Theory, lab and space experiments, and calculations related the physics of [plasmas](https://en.wikipedia.org/wiki/Plasma_(physics)), i.e., matter constituted by [ionized atoms](https://en.wikipedia.org/wiki/Ion).

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Does the motion of a free electron in a plane wave electromagnetic field have analytical solutions?

Does the motion $[x(t), y(t), z(t)]$ of a free electron in plane wave electromagnetic field have analytical solution (oscillating E and B fields)? The Lorentz force is : \begin{align}m_e\begin{...
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36 views

How strong is Earth's magnetic field in space?

I've been searching around Google and Youtube about the strength of Earth's magnetic field. By the help of wikipedia, I have found out that it's magnitude is 25 to 65 microtesla or 0.25 to 0.65 Gauss ...
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1answer
53 views

In a fusion reactor like Tokamak, how is fuel injected without destroying the fuel injector? [closed]

Plasma temperatures in a tokamak are around 100 million C. Presumably for a power plant that will run for a long period of time, fuel will have to be injected and "burnt" products will have to be ...
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65 views

is the sun going to make an electromagnetic pulse in the next 50 years?

EMP is very damaging and can cause blackouts and other bad results specially on electronic devices , so i heard that our sun is going to make an electromagnetic pulse during the next 50 years ..is ...
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1answer
16 views

Why is it that only thermal energy is available in a particle propagating throughout a space-charge layer in a plasma (not kinetic)?

In this PDF on page 5 the author explains that a particle moving through a space-charge (electron density in a plasma) gains only thermal energy. Should there not also be kinetic energy?
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What is meant by Hydrogen dilution in Plasma?

I was going through the paper of methanol masers and it says that for a strong maser the geometrical dilution factor of HII emission should have low values. What is the meaning geometrical dilution ...
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38 views

Refractive index of plasma dependance on temperature

How does the refractive index of plasma changes with temperature? Temperature is not high enough for new ionization. Would it be like in gas p/T dependence ? http://farside.ph.utexas.edu/teaching/em/...
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Create spinning / modulating plasma effect without spinning the whole appartus

I'm trying to create a variable spinning / modulating plasma effect without turning the whole apparatus as seen in the video. https://www.youtube.com/watch?v=Wis_HEa3X84 Is it possible to just use ...
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15 views

Plasma generated with gas and how far does it penetrate the skin

I know Far Infrared can penetrate the body’s tissues 1.5 inches (almost 4 cm) beneath the skin. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3699878/ But how far will a plasma field generated with ...
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Why does AC Conductivty in Drude Theory have an Imaginary and a Real Part?

In the Drude Model the direct current (DC) conductivity is given by the following formula: $$\sigma_0=\frac{ne^2 \tau}{m}$$ where $\tau$ is the relaxation time. Furthermore, the AC conductivity in ...
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26 views

What is the refractive index for partially ionized plasma plasma (mixture of electrons ions and atoms)?

I asked a question earlier, why ions are not included in refractive index of plasma . What I do not understand is how a refractive index of plasma can be formed mathematically that is just partially ...
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71 views

Why in plasma physics usually is given the refractive index of electrons but not for ions?

What is the refraction index of ions in plasma ? And why people do not discuss it in books ? Is it that it is not important for plasma phenomena ?
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Simulation of plasma in tokamak

I am reading some papers on numerical algorithms for simulation of plasma in the context of nuclear fusion in a tokamak. I am getting a little lost as there is a huge number of references, and it is ...
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110 views

Vlasov equation, Maxwell distribution

I have the Maxwellian distribution: $$f(v)=n\left(\frac{m}{2\pi kT}\right)^{\frac{3}{2}}\exp\left(-\frac{mv^2}{2kT}\right)$$ I have to show that it is a solution to the Vlasov equation: $$\frac{\...
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1answer
37 views

How do flames neutralize a static charge?

I was working with a demonstration galvanometer recently when it accidentally picked up a static charge from me lightly rubbing my hand across it. The case was made of a clear plastic. My attempts ...
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Ionospheric electron density measurements

I've been working on measuring total electron column density (TEC) with multi frequency GPS data. In theory, signal delay caused by TEC differences should affect the code and carrier nearly evenly in ...
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20 views

Can a Van de Graaff Generator be used to put plasma at high potential?

Lets say hypothetically, we use a sphere of plasma (ofcourse lab-plasma, stabilized somehow) instead of a sphere of metal in a van de graaff generator. Now can we use it to put a large amount of ...
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21 views

Can additional charge be put on plasma?

We all know that plasma is electrically conductive. My question is that is it possible to somehow place more charge on it (lets say like a capacitor) such that it produces its own electric field ...
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54 views

Possible Safe Areas In a Solar Flare

Which part of the earth would be the safest in case of the major solar flare? Will it be near equator or something like that?
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1answer
38 views

What causes a charged particle to follow circular motion in a magnetic field? [duplicate]

I would like to know why particles follow a circular path in a magnetic field, what path they trace and how this path is measured and controlled?
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2answers
50 views

Does the solar wind correspond to a net electrical current?

The solar wind is a stream of ions emitted from the sun. Are there more positive than negative charges released? That is, is there any imbalance in the charge emitted from the sun in the solar wind?
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Why does an oscillating electric field couple more strongly to electrons than to ions?

As stated in Principles of Plasma Discharges and Materials Processing, by M. A. Lieberman and A. J. Lichtenberg, about capacitively coupled plasmas: (...) the light and heavy charged particles in ...
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25 views

The velocity of the charged particle in the magnetic field [duplicate]

Enrico Fermi considered that moving charged particle gains energy in the magnetic field, so its velocity increases. According to the Lorentz Law $\vec F=q\vec v\times\vec B$. Work is $A=\vec F\times\...
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45 views

Why doesn't the group velocity of a plasma EM wave equal the phase velocity here?

For plasma EM waves we have the dispersion relation $$\omega^2=\omega_p^2+c^2k^2$$ where the plasma frequency $$\omega_p^2=\frac{n_e e^2}{\epsilon_0 m_e}$$ One can show that $v_p v_g=c^2$, i.e., the ...
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What is the role of plasma in nuclear fusion energy production?

I read that confined plasma in electromagnetic field uses in TOKAMAK nuclear fusion reaction. But I don't know what is the main role of plasma in fusion reaction. Is it use for producing energy ...
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53 views

Can conducting electrons in a metal be modeled at all as classical particles?

I have seen computational models that treat the highest energy electrons in a conducting metal as classical particles in a plasma, the ions being held in place with some sort of heuristic nearest-...
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What is the difference between metallic hydrogen and plasma of hydrogen?

As far as I know, metallic hydrogen and plasma seems share some common properties, eg:conduct electricity, nuclei share electrons, high temperatures... So my question is, is metallic hydrogen in fact ...
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183 views

Is there any electric current in a continuous medium of moving charges?

Consider a continuous charged fluid (unlike in real life where charge is carried in discrete chunks like electrons) in a bottle. Suppose that the fluid is stirred in a circular manner and then left to ...
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23 views

Project Orion pusher plate computer modeling

Linked from the space.stackexchange forum: http://space.stackexchange.com/questions/15051/orion-project-npp-pusher-plate-computer-models-and-survivability Project Orion is discussed as if it is a ...
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790 views

Do stars remain electrically neutral? [duplicate]

How electrically neutral do stars remain through their lifetime? As an example, I could imagine processes such as coronal mass ejections leaving the Sun in a slightly charged state. Are there such ...
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2answers
76 views

A question about the Fermi acceleration

In high school physics, we know that a charged particle cannot gain energy from a magnetic field. But, it seems that in the so-called Fermi acceleration, the particle is accelerated by the magnetic ...
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21 views

GEN3's 10nm-30nm Contiuum Radiation Measurements

What is the most likely explanation for the 10nm-30nm continuum radiation reported in "Validation of the Observation of Soft X-ray Continuum Radiation from Low-Energy Pinch Discharges in the Presence ...
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43 views

Does nuclear fusion of light nuclei occur in fire or boiling water?

At the temperature range of ordinary fire or maybe even ordinary boiling water, is the Coulomb potential between light atomic nuclei occasionally overcome to give way to fusion? Basically, how are ...
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Plasma Seperation Technique

Is it possible to break a gas sample in ions and separate those ions and store in two different tubes? If there is an experiment and formula related to it then please mention that too.
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36 views

Is the permeability of plasma equal to the permeability of free space?

I learned that in Maxwell equations for plasma, the permeability is equal to the permeability of free space so that means the relative permeability is equal to the unit tensor. Also we have always ...
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1answer
75 views

What causes polarization current density in plasma?

Plasma current density is defined as $\textbf{j}=-\mathrm{e}n_e\textbf{u}_e$ where $\mathrm{e}$ is electron charge, $n_e$ is electron concentration and $\textbf{u}_e$ is electron velocity. What ...
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Schwinger metals?

Consider an electromagnetic field that does reach values above the Schwinger limit inside a region of space $R$, on each oscillation. Once the field exceeds the Schwinger intensity, the field causes ...
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19 views

Ion Source Design

I want to design a DC arc discharge ion source but I can't find a good book that explains how to do it. Can anyone please recommend me a book or paper that explains this? thanks
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28 views

Polarization current introduced by induced charge?

Should we count the current density that introduced by the movement of induced charge as free current or magnetized current or neither? And why?
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Physics 3 recommended book with solutions [duplicate]

I'm new to this forum and wanted to ask for a recommendation for a book which has these subjects with problems and solutions:(if this is not a valid question please tell me) -Intro to Waves -Fourier ...
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2answers
54 views

Is green superheated plasma possible?

I've noticed that video games like Fallout 4 depict the plasma fired from plasma weapons as green. Is there a way hot plasma can look green in real life? I know some gases emit green light when ...
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1answer
45 views

Recombination rate/time calculation for plasma vs. solid state semiconductors

I've been able to find how to calculate the recombination rate for semiconductors as a function of the type of semiconductor (like silicon), the doping material, the concentration of the excess ...
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1answer
78 views

What phenomena occur in a low voltage arc between copper and graphite electrodes, and why is the result dependent on electrode polarity?

I was playing around with a laboratory power supply, drawing arcs between electrodes of various materials. I noticed phenomena that I found interesting, and couldn't really explain myself: The ...
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104 views

What makes Jacob's ladder spark to go upwards?

In a Jacob's ladder (https://www.youtube.com/watch?v=GaC4BnbH1NY&index=3&list=PL_SAbPKia2YMFi-t8z5WFYCd86Plcs1Un) a spark is originated in the bottom and climbs up to the top. I have read in ...
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1answer
77 views

Do plasmas have their own magnetic fields?

Do Plasma generate a magnetic field of their own ? Can they cause electromagnetic induction?? For example if a hydrogen plasma is ionized and its electrons removed.. And the protons accelerated ...
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1answer
62 views

1kg mass impacting at half light speed - effects?

Such a mass would have kinetic energy approximating a 1 mega-tonne thermonuclear weapon. So, what would such an object do if it hit the Earth? We know how destructive such an energy release can be, ...
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121 views

What state of matter is thunder? [closed]

I know of solid, liquid and gaseous states of matter but what state of matter is thunder? Is it gas, liquid or solid?
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254 views

Why is a stellarator-type nuclear fusion reactor so oddly-shaped?

My first impression: It's a mess. Why is it shaped like that? I can't find any info about its shape other than it's a special arrangement of magnetic coils. (link) Here's some more images of it on ...
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126 views

Why did they start Wendelstein 7-X With Helium?

Just saw the first Hydrogen plasma at the Wendelstein reactor. I haven't found anywhere that gives a good explanation as to why they first used a Helium plasma - can anyone shed any light?
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Potential energy of a spherically symmetric charge density in a spherically symmetric electrostatic potential

I'm interested in calculating the potential energy of a spherically symmetric charge density in a spherically symmetric electrostatic potential. More specific, I'm currently trying to calculate the ...