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

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How does a Pulsed Plasma Thuster work?

My friend was describing a Pulsed Plasma Thruster (PPT) to me, and we couldn't figure out how it actually worked. The setup involves two conducting plates with a potential difference and a solid, ...
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2answers
239 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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27 views

Units in Plasma Physics

What are the units people use in plasma physics? I am having hard time converting an equation from an old paper to SI units. I saw temperature being defined in $eV$. I assume this is $eV/k_B$ with ...
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Is Keshe's technology for real?

http://www.youtube.com/watch?v=UrN99RELqwo (Video Title: "Keshe Foundation Promo Intro Video (english with multiple subtitles) === PLEASE SHARE ===") In this video they claim that they can create ...
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Why can xenon gas stay ionised after the “trigger voltage” is removed?

From my understanding of a Xenon flash circuit, a storage capacitor and a trigger capacitor are charged up to about 240V (both with similar RC values, but less capacitance is needed for the trigger ...
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polarization of a transverse wave travelling in ionosphere with polarization direction perpendicular to earths magnetic field

Assume a transverse electromagnetic wave entering ionosphere such that its Electric field of wave is perpendicular to earths magnetic field. Now, i read that as it will enter plasma, the wave will ...
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What happens to Hydrogen-Boron plasma at 3 billion Kelvin?

A recent popular report states (beware, I believe it is not peer reviewed and this slightly smells like a PR stunt) that a private company TriAlpha has made some notable progress towards ...
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What is the role of the Cowling, Pedersen and Hall resistivities (or conductivities) in plasma physics?

The current density $\vec{j}$ can be computed as $\vec{j} = \vec{\vec{\sigma}} \vec{E}$, where $\vec{\vec{\sigma}}$ is the conductivity tensor and $\vec{E}$ is the electric field. This conductivity ...
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48 views

Using ion beam to create strong magnetic field

Consider, I want to make very strong magnetic field in some spot in space ( focus ) but I cannot put any solid material ( like metal conductor, or superconductor ) close to that spot (e.g. because ...
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540 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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35 views

Is thermal and electrical conductivity correlated for all phases of matter?

After reading this interesting post about why copper is a great heat conductor, I wondered if a plasma would conduct heat better than a gas. Or, are some properties like density more important for ...
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37 views

Induction equation in a rotating frame

In his book, Tom Cravens refers to the induction equation (perfectly conducting limit) in a rotating frame, the Sun. See link below: ...
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Electron beam in magnetic field - increase or decrease the field?

When I fire an electron beam into homogenous magnetic field ( eg. inside Helmholtz coil ) it will bend into a circle => it will form a coil ( = current loop ) itself. The magnetic field created by ...
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148 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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Measured versus Predicted Energy gain in Tokamaks with size

Does there exist a known relationship between the energy gain of Tokamaks in dependence of their size? How do fusion engineers can predict how much gain will a given Tokamak size deliver? Do they just ...
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13 views

What is the resistance of ionised Xenon gas?

I need to know the typical resistance of ionised xenon gas inside a xenon flash tube, so I can use circuit analysis to calculate the flash duration. I know that a 180uF capacitor is charged to ...
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153 views

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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268 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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56 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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190 views

Relationship between plasma physics and quark gluon plasma

To what extent do the ideas common in modern plasma physics, such as magnetohydrodynamics, cold plasma models, common types of plasma waves, Maxwell's Equations, etc, relate to the study of quark ...
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42 views

Geometry of magnetic field lines in plasmas/MHD

So I'm trying to gain an intuitive grasp of plasmas and magnetohydrodynamics. There's a couple of questions I have. What does it means magnetic field lines are frozen into "plasmas"? Is it that ...
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38 views

How to calculate electrical and thermal conductivity, enthalpy and density of plasma column in air for a series electric arc?

I am modeling an electric arc according to "Lowke's Simple theory of free burning arc". Its a very interesting theoretical arc model and I want to implement it in Matlab/Simulink. But here, the arc ...
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111 views

What happens to charge during laser ablation in water?

One of my friends from lab makes gold nanoparticles in the following manner: He puts a gold plate in water (without surfactants or other additives) He fires laser at the plate After 5 minutes ...
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55 views

Book suggestion for introductory plasma physics

I have an undergraduate background of electrodynamics, special theory of relativity and quantum mechanics. I would like to study plasma physics by myself so please suggest a few introductory books on ...
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why is clear electron saturation not obtained in a Langmuir probe experiment?

I recently conducted an experiment to study the I-V characteristics of a Debye sheath, but I can't obtain electron saturation. Why does it happen?
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Is magnetic reconnection reconcilable with magnetic field lines neither starting nor ending?

According to Maxwell's equations, magnetic fields are divergence-free: $\nabla \cdot \mathbf{B} = 0$. If I understand this correctly, this means that magnetic field lines do not start or end. How can ...
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Are x-rays in fusion plasmas mostly from collisions with high atomic number ions?

Say you have a hot (100eV-1keV) hydrogen plasma with no impurities in it and no collisional interaction with the wall. Would this plasma radiate x-rays? X-rays are from bremsstrahlung, so could ...
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44 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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60 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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38 views

Is plasma an intermediate stage of matter? [duplicate]

Can it truly be called a stable state? Fire is stable while it has fuel but isn't it really just a transition point for solid to gas?
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Find the fraction of atoms in specific quantum state in stellar atmosphere [closed]

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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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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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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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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29 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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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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294 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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5k 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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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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178 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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145 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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93 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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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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289 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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158 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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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 ...