Plasma Definition and 618 Threads

Hello All I've got two years left in my Physics undergrad degree at a university in Ontario, Canada. My ultimate career goal is to do research in fusion energy, and I've just started looking into what steps I should take to get there, starting with grad school. Naturally, I have some...

Hi, I do not know if this is the right section to post my question. Anyway here I go.. Can anyone give a brief explanation of Bohm's criterion, that is the concept of pre-sheath. Thank you.

From the primal plasma how many elements (could) have formed that are not detected? or is the larder full.

Homework Statement 'Briefly describe two different kinds of plasmas and in each case describe how the plasma arises.' Homework Equations http://en.wikipedia.org/wiki/Plasma_(physics) The Attempt at a Solution I think i understand what a plasma is, but are there different types of plasma...

Hello, In my plasma physics book, poissons equation in relation to a plasma made up of electrons and protons is given as \frac{1}{r^{2}}\frac{d}{dr}\left(r^{2}\frac{d\varphi\left(r\right)}{dr}\right) = \frac{2}{\lambda_{D}}\varphi\left(r\right) The solution of this equation when phi(r)...

Homework Statement The dispersion relation for a plasma is given by k^{2}=\frac{\omega^{2}}{c^{2}}(1-\frac{\omega^{2}_{p}}{\omega^{2}})\omega^{2}_{p}\:= \frac{Ne^{2}}{m_{e}\epsilon_{0}} Where N is the electron density During re enrty of a spacecraft there was a radio blackout of all...

Electromagnetic wave with higher frequency then plasma frequency are barely attenuated. I always hear that the reason is the electrons can't oscillate fast enought... how does that actually work? (how can an electron not be able to oscillate at the same speed?)

When i calculate a plasma frequency with the equation : ω=square root (4*pi*n*e^2/m) are the electrons always of that frequency or is it a maximum that an electron can oscillate?

Why are electromagnetic waves reflected when they comme in contact with a plasma ( with a frequency lower then the plasma frequency, and I am trying to find precisely why the wave cannot pass ). I was also wondering if conductors (metals) are considered to have a plasma frequency ty

My best offer for graduate school has turned out to be University of Wisconsin - Madison for the Department of Nuclear Engineering and Engineering Physics. I plan on focusing on theoretical/computational plasma physics and magnetic confinement fusion. Does anybody have any personal...

Is a plasma a fluid?

What if any, is the best model that starts with the primeval plasma and produces any results that would lead in some way to a universe? Edit I think i should have said simulation.

I just finished reading the Wikipedia article on the quark-gluon plasma and it states that because of the large coupling, lattice-gauge theory is used instead of perturbation theory/Feynman diagrams. However, I thought the coupling decreases with increasing energy (asymptotic freedom), so...

Hi everyone, I'm not sure if this is a basic EE problem as I'm in aerospace and I would like to apologize if i posted in the wrong forum. I've attached a circuit diagram of my design. The capacitors and the 2 higher resistors are of variable values. The switch and the lower resistor...

how "large scale" is plasma physics I'm a physics undergrad right now, and I'm trying to pick out classes I want to take to get a better idea of what I'd like to do in grad school. I've wanted to work on fusion/plasma physics for a long time, and right now I'm reading a book on the history of...

Hello all, I am currently a second year engineering physics major, specializing in Nuclear Engineering. What would be the best Math and Physics courses to get an idea of what fusion engineering and/or Plasma physics is like (My university does not offer any formal fusion engineering classes)? I...

50" 88lbs Plasma TV mount on Stand - Free Body Diagram Hi, I am building a customized stand for my palsma tv. I already have the base, made of 2" square iron tubes. I am about to design the mount for the screws, but I was wondering what forces should I consider for this. The base is in...

Is it possible for plasma to be conducted through a metal wire? I was wondering if you supply the wire with enough plasma to light a low power LED.

I had a idea a while ago about a possible energy generator. I was wondering if you set up a plasma arc, then circulated gases through the arc so they would be ionized. Then, the ionized gases were moved through to a wire net through means of a strong fan or magnetic fields. Would it be...

Homework Statement I'm trying to work out a theoretical problem, and I don't know how to approach it. Suppose I have a charged gas that is traveling near the surface of a magnetically-responsive solid. I would expect the charged gas to be generating a magnetic field. I would also expect...

Gas core reactor rockets use nuclear gas reacting to super heat and therefore pressurize hydrogen. They operate at about 25000 C. Why not use a high intensity plasma arc which routinely operate at about 13,000 C but if designed to can go much higher by at least several fold. I got bored...

I believe it seems possible that a plasma generator could be constructed to ionize the gases used in the making of the plasma. A plan needs to be worked out to construct an energy collector to collect the energy that is given off by the ionization of the plasma gases. Now, in order to "recycle"...

Homework Statement A cylindrically symmetric plasma column in a uniform B field (= B0 in z direction) has n(r) = n0 exp[-(r/r0)^2] and ni = ne = n0exp[e phi/kb Te] where phi is the potential and Te is the temp of the electrons. (a) Show that Ve and VDe are equal and opposite Homework...

Is it possible to use plasma as a heat shield for a re-entry vehicle? We all know that plasma isn't very dense, but then neither is the thin upper atmosphere that causes re-entry heating in lieu of drag. I'd read that a simple trick used by ICBM warhead engineers, was to simply have a...

Homework Statement Derive the moments equations for a plasma. I specifically need help developing the 2nd moment equation (the Energy Balance). I can't get one of the terms... Homework Equations The Boltzmann Equation: \frac{\partial f_{\sigma}}{\partial t} + \vec{v}\cdot \nabla...

hey, I have a question, it might be really stupid, but I'm probably not as smart as any of you here. Anyway: if you had a sustained plasma field held in place, maybe spinning in a toroidal motion, is it possible to "harvest" free electrons from the field by an anode, and feed it back into the...

There are many videos on youtube where people put grapes in the microwave and it turned the grapes into plasma. There are some other videos on youtube where someone made a plasma thruster(http://www.youtube.com/watch?v=s_wwEKp6SGk"), and in the discription said that it needed a magnetic field...

My parents have a 3yr old LG Plasma HDTV. Last month the color in the screen appeared to shift or fade. Then the screen started to flicker. Then the TV could be turned on with audio, but no screen, just black. The strange thing is that if we unplug the TV for a few hours and then plug it...

what happens to a body of water when coming in contact with plasma - such as the plasma cutters? I've been thinking if you had a cylinder filled with some water and something like a plasma "spark plug" you could get some serious vapor pressure. Is this an accurate estimation, or am I way...

Hi: Quark gluon plasma is created at very high temperature, right?. Could you please explain me what happens to Quark gluon plasma after it is cooled?, is it possible to use quark gluon plasma to create nucleons? Thanks

I don't know if this belongs here but here it goes. I started to think about it(not much however) when reading the last phrase in this thread https://www.physicsforums.com/showthread.php?t=57607&highlight=plasma+physics "As my QM professor kept saying this semester, "If you hate this...

Hello, I've been watching some videos on youtube of people putting a lit flame into a microwave oven. After a few seconds the flame bursts into a bright ball of plasma, why is this? Is there anywhere online that I can research the science that causes this...

Too lazy to post two binary polls. Do you recommend/prefer LCD vs. plasma? Do you recommend extended warranty or not?

Does the concept of capacitance also apply to positively-charged plasma particles in a strong enough electric field? In other words, is it possible to accumulate positive gas ions on one side of some apparatus (or one side of a vacuum tube filled with a very small amount of gas) if a strong...

This is a neat paper I found, its a quick read. http://www.isso.uh.edu/publications/A2006/2006_043_garrison.htm

Hello all, Are there any such major as for Plasma Physics or Plasma is just an option? What are the different types of Physics minus Astronomy? Is astrophysics part astronomy and part physics? If so we can forget about astrophysics. What are some good public not private colleges for physics...

Dear PFers, could somebody provide an update on the searches for quark gluon plasma, the color glass condensate interpretation, and/or their conceptual basis ? I have found a few big documents, if somebody knows where to find the latest review it would be most welcome. I would like a preview...

if the Plasma membrane is amphipathic (hydrophobic and hydrophilic), why does it only allow hydrophobic stuff to pass thru?

[SOLVED] light diffraction in plasma This is my first post in that forum and I hope someone will help me.:redface: It is known that photons with frequency lower than the natural oscillation frequency of plasma are reflected , but those photons with slightly lower frequencies are they fully...

not sure if this is in the right section but... What exactly causes plasma to reach such high temperatures?

A complete set of lecture notes for a graduate plasma physics course. Topics covered include particle orbit theory, fluid theory, wave theory, MHD theory, and kinetic theory. by: Richard Fitzpatrick (University of Texas)

I am still trying to get a handle on plasma behavior, if I had a gap intended to apply a field for the purpose of compressing a hydrogen ion stream, using the Z-pinch effect could one discharge a current through the ion stream to affect the Z-pinch? I am thinking that it would, that the...

what is the concentration of blood plasma under normal conditions?? how do you even begin to answer this question HELP!

Hi, I'm studying plasma waves now, and we have talked about waves in class that have phase velocities faster than the speed of light. For example, some of the waves from the Appleton-Hartree dispersion relation have this characteristic. I asked my professor about it and he said that is...

I'm having a problem understanding QGP. Hadrons are bound states of quarks which interact by interchanging colour. Now, as I understood we haven't observed free quarks because the force rises by distance and that force is really strong. As I read in QGP quarks and gluons are not bound, you can't...

I'd heard this was a relatively newer discovery -- that a blunt-body object traveling through a gas experiences a reduction in drag if that same gas is turned into plasma. I'm haven't read exactly why this occurs, but I'd presume that a gaseous fluid medium becomes easier to pass through if...

I found a video called "how the sun really works" on youtube. Link: http://www.youtube.com/watch?v=ihVaL-FHUyk" Well. This did not make much sense for me. Is there something to be debunked?

Hey everybody. I heard a physics professor at Berkeley say that normal fire (from a lighter) is plasma. My science teacher at high school says that it isn't. So my question is, is normal fire in state of plasma or not? Thanks.

Hi, Let's consider a plasma of 3 distinct populations : 1 cold proton population of 0.2 density, 1 hot proton population of 0.8 density, and one electron population. I have T_i=T_e and I set the velocity of my cold population to 0. I expected that te energy of my hot proton population to...

The electric universe http://video.google.com/videoplay?docid=4773590301316220374 many claims that challenge main stream cosmology.