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

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Integrating Factor Solution for Plasma Wave Equation

As part of a derivation in Bernstein '58 [1] a linear first-order (eqn. (9) in the image) appears: But the general solution I would usually take (as appears in Gradshteyn and Ryzhik and checked in ...
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19 views

Find the fraction of atoms in specific quantum state in stellar atmosphere [on hold]

Consider gas consisting of hydrogen atoms at temperature about $T \sim 5 \cdot 10^6 \text{ K} \approx 431 \text{ eV}$ and concentration $N \sim 10^{11} \text{ cm}^{-3}$. I need to find the fraction of ...
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33 views

How do I calculate the energy flux for this toroid?

My question is how do i calculate the total energy flux through the walls of the torus in this situation? The Poynting flux is given by $\vec{N} = \frac{1}{\mu} ( \vec{E} \times \vec{B})$ but the ...
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Difference between fusion plasma and fluorescent lamp plasmas

How is the plasma in a compact fluorescent lamp (CFL) different from a plasma in say ITER or the sun? Why does ITER need 100MK and a CFL can work at practically room temperature (apart from the ...
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83 views

Real life physics problem: Why is my desktop computer affected by my plasma ball?

Note: this is strictly a physics question, not meant to be an advertisement I was running my desktop with a plasma ball on the side. The desktop has a touch screen enabled. I started to notice that ...
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10k 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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What is the effect of a magnetic field on a plasma speaker?

I have been doing some research for the past couple years investigating the effect of a magnetic field on a plasma speaker. More specifically, if you apply a relatively uniform magnetic field in no ...
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14 views

Plasma wakefield acceleration for Protons

Laser plasma acceleration is a promising technology that could replace the current method of accelerating particles (which is via electric fields). It is somewhat cheaper also as it makes the ...
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470 views

Child-Langmuir Space Charge Law for Non-Zero Cathode Potential (Non-Zero Initial Electron Velocity)

I'm trying to reconcile some conflicting results that I've found in publications that address the idea of the current in a vacuum diode in the case where the cathode has a non-zero potential, in other ...
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21 views

Production of Inductively Coupled Plasma

I am working on an experiment hat requires the usage of inductively coupled plasma, but unfortunately, I do not have any equipment at the moment that can produce such plasma, and I really need your ...
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17 views

Why are low m,n modes more dominant?

Consider an axially symmetric, toroidal, magnetized plasma with some safety factor (q) profile. A flux surface has q=m/n where m is the number of toroidal transits and n is the number of poloidal ...
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42 views

Modified Bessel equation with Gaussian source [migrated]

I'm studying a system in which a neutral particle beam with a Gaussian profile of known width $w$ enters a plasma. The beam produces secondary particles, which diffuse and are ionised through a ...
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228 views

Dielectric tensor vs. conductivity tensor in (cold) plasmas

I'm studying Waves in Cold plasmas right now, but I guess my question is generalizable. It's about the 4th Maxwell Equation in polarizable / conductive media: $\nabla \times H = \frac{1}{c} ...
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2answers
4k 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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2answers
115 views

What materials are used in non thermal plasma?

While reading about non-thermal plasmas, I came across their ionization potentials(~1%), and other capabilities, such as their non Maxwellian energy distributions. At what temperatures, and pressures ...
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22 views

Betatron vs Fermi acceleration

According to the reference below, the plasma in a planetary radiation belt increases its temperature anisotropy through radial diffusion; temperature perpendicular to the background magnetic field ...
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157 views

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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3answers
121 views

Do different plasmas from different elements have different properties?

If so, what are some differences? Like between iron and gold? EDIT: Sorry, I need to clarify: By 'difference' I mean... do they retain their chemical properties from more normal temperatures? Like is ...
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36 views

What's the difference between “Ohmic dissipation”, “Joule heating”, “ion drag” and “resistive heating”?

The following terms are sometimes used to refer to ... more or less ... the same thing by different people and in different contexts (electronic circuits vs. plasma physics, etc.): Ohmic ...
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51 views

Why do rings form on microwaved CD/DVDs?

Here's a microwaved CD. As you can see, the disc has been destroyed, but there are very clear circular rings bridged with lines. Why are rings formed when microwaving discs?
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Finite Value of Cross Section of (Scattering/Absorption) of Localized Surface Plasmon at Resonance

According to textbook written by Stefan A. Maier, ch.5, p.70, cross section of scattering and absorption are defined as: $$C_{sca}=\frac{8\pi}{3}k^4a^6 ...
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249 views

How does the sun's surface conduct thermal energy from the convective zone to the corona?

How does the surface of the photosphere conduct thermal energy from the convective zone to the corona, while remaining at such a relatively low temperature itself? It seems odd to me that the ...
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Apparatus for generating plasma

I'm working on a project which involves superheating nitrogen to a state of plasma. I was considering using my Fusor, but this project has nothing to do with plasma, and I believe that there are way ...
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3answers
99 views

Liouville's Theorem and Boltzmann equation for plasma

The Boltzmann equation for a plasma can be thought of as coming from a continuity equation in the 6 dimensional phase space of the plasma with coordinates $\left\{x,y,z,v_x,v_y,v_z \right\}$. So ...
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46 views

Can someone explain diamagnetism in plasma?

Diamagnetic plasma has an internal resistance to an outside magnetic field. I thought that a good analogy for this would be electrical resistivity. In high school we learned that different ...
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47 views

Can we create plasma with other things except gas?

In my school book its written on how plasma is created and it is said that we can create plasma by ionizing a gas but i have heard that plasma can be created even from liquids like water and also from ...
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How does electron positron plasma act compared to normal plasma?

When an electron positron plasma is formed, will it react to magnetic fields the same way? With the gamma ray photons resulting from the annihilation, would the plasma be of greater energy? Thanks!
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plasma and infinite acceleration

I am trying to set up a simulation of particles (they are not any particular kinds of particles, they are just points that repel each other). All the particles repel each other through the inverse ...
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38 views

How do I find the partition functions for the Saha equation for elements that are complex like Argon?

The question I have is with regards to the partition function needed for solving the Saha equation for Argon. Basically the part I'm confused with is the part of the formula where $g_i/g_a$, where ...
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167 views

Particle-in-cell (PIC) code Virtual Laser Plasma Lab (VLPL)

I am writing a simulation code to model betatron X rays produced by electrons accelerated using laser wakefield acceleration (LWFA). I have heard about 3D PIC (Particle-in-Cell) code VLPL (Virtual ...
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6k views

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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nuclear fusion scaling with reactor size

Thinking about physics of thermonuclear fusion, I have always intuitive sense, that making fusion feasible is matter of reactor size. In other words I feel like: if the fusion reactor is big enough ...
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26 views

Calculate energy-density of known plasma in microwave?

Let's assume I want to create a plasma in a regular household microwave similar to this home-made experiment. Although I am dealing with a small amount of mass, I assume that the addition of microwave ...
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35 views

Dense plasma focus properties

Any Dense plasma focus scientists here? Could you explain the effects of having the anode: with less number of rods? hollow/non-hollow?
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34 views

Is it possible to heat plasma to the point where there is no electrical resistance?

I was discussing Ohm's Law with my teacher and asked about what would happen if the resistance of a circuit was zero, to which he replied that the wire would melt. This got me wondering about ...
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78 views

Drifting Maxwellian distribution for energy

Assume I have a drifting Maxwellian distribution with velocity $\vec{a}$, say, in the x-direction, so something like $$ f(\vec{v}) = n\left(\frac{m}{2\pi ...
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Why do the high curvature bends in CFLs have their phosphor coating erode?

I have this pretty old compact fluorescent (CFL) bulb from several years ago still going strong. There was a period where the bulb sat unused when I moved away from home and put the lamp in storage. ...
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99 views

Fusion - A List of Experimentally Achieved Beta Numbers in Magnetic Confinement [closed]

I want a list of all the beta numbers achieved in across all magnetic fusion energy devices. This is not theory, but the actual number measured experimentally. No list like this exists. The beta ...
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99 views

Magnetic Energy Density Equations

I have a plasma with a magnetic field through it and I want to know the magnetic energy within the plasma. I have the simple equation U=(B^2)/mu for the energy density. But my question is then, if ...
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2answers
52 views

Gravitoelectromagnetism higher-order effects

See http://en.wikipedia.org/wiki/Gravitoelectromagnetism#Higher-order_effects According to the Higher-order effects... "Gravitomagnetic arguments also predict that a flexible or fluid toroidal mass ...
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75 views

What causes the electrical reaction between two carbon rods touching?

I recently watched this video in which carbon rods from a 6V lantern battery are removed and then touched together to create a makeshift arc reactor furnace. This produces electrified plasma which can ...
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102 views

Fusion reactors why does size matter?

I've been following articles about fusion recently, and with the ITER project mostly. I have noticed that their view point is they need to build a large scale reactor in order to achieve their goals. ...
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874 views

Formula for Electrical Arc Length

I was playing with some High-Voltage the other day, when a question popped into my head. Can you calculate length of an electrical arc? It probably would be proportional to :- 1. Voltage of the source ...
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Calculating the magnetic permeability of a known plasma

I have a plasma, of which I know the composition, temperature, exact electron/ion/particle densities. How can I then calculate a theoretical permeability of the plasma. Is this even possible? I ...
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71 views

Does plasma has any chemical formula?

As far as I understand, plasma is another stage of matter like solid, liquid or gas. All of these have chemical formulas, however does plasma has chemical formula as well? If it doesn't, what's made ...
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Why does a non-contact voltage detector light up when you touch a plasma ball with the other hand?

I am doing a science experiment and we decided to try holding a non-contact voltage detector up to plasma ball. We were surprised that it would light up when it was 3 ft away from the plasma ball. I ...
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1answer
90 views

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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52 views

Fermi velocity $v_F$ and speed of light

Can Fermi velocity $v_F$ be equal to speed of light, $c$, for ultra-relativistic electron plasma waves, in plasma physics, by using Fermi-Dirac distribution function?
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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?