Plasma (from Ancient Greek πλάσμα 'moldable substance') is one of the four fundamental states of matter, first systematically studied by Irving Langmuir in the 1920s. It consists of a gas of ions – atoms or molecules which have one or more orbital electrons stripped (or, rarely, an extra electron attached), and free electrons.
Plasma can be artificially generated by heating a neutral gas or subjecting it to a strong electromagnetic field. The presence of free charged particles makes plasma electrically conductive, with the dynamics of individual particles and macroscopic plasma motion governed by collective electromagnetic fields and very sensitive to externally applied fields. The response of plasma to electromagnetic fields is used in many modern technological devices, such as plasma televisions or plasma etching.Depending on temperature and density, a certain amount of neutral particles may also be present, in which case plasma is called partially ionized. Neon signs and lightning are examples of partially ionized plasmas.
Unlike the phase transitions between the other three states of matter, the transition to plasma is not well defined and is a matter of interpretation and context: Whether a given degree of ionization suffices to call the substance "plasma" depends on a specific phenomenon being considered. In other words, plasma is a matter which cannot be correctly described without the presence of charged particles taken into account.
Excluding dark matter and the even more elusive dark energy, plasma is the most abundant form of ordinary matter in the universe. Plasma is mostly associated with stars, including our Sun,
and extending to the rarefied intracluster medium and possibly the intergalactic regions.
I observe that electric arc forms a curve. I think that this is because electric arc is extremely hot and hot air goes up because it has less density. So if electric arc occur at 0 gravity would it be straight?
from wikipedia https://en.wikipedia.org/wiki/Electric_arc
Thank you.
Homework Statement
Hi!
I have trouble with calculating the upward and downward plasma speeds. I have the necessary data and an equation that is useful (I think), but I'm stuck.
Homework Equations
The shock jump number Zs=3 in this case , and I've calculated the shock wave speed (555 km/s)...
My question is about Force Free fields in the study of plasma stability (in MHD regime): Consider an isolated ideal plasma in an equilibrium state (where the effect of selfgravity is negligible), from the Navier-Stokes equation we get that:
$$\vec{\nabla} P = \frac{1}{c} \vec{J} \times...
A magnetic field doesn't penetrate well into a plasma because it produces currents that counters the field, so to speak. But, before those currents are produced, does the whole of the plasma "feel" the magnetic field? For how long; ns, us or ms?
S.A.
Hello all,
This might sound very optimistic for a project but I want to design a thermonuclear fusion reactor. Does anyone know how I can calculate the required plasma current I need in order to start a thermonuclear fusion process? I am using a mixture of Deuterium-Tritium gas.
Thanks!
I'm trying to understand the mechanisms of the anisotropies in the CMB. The general idea is that there are fluctuations in some field (e.g. inflation) and the baryonic and dark matter rush into the space compressing the fluid. The photon energy pushes back on just the baryonic matter while the...
Let's say we have a plasma of protons or deuterons and electrons; how thick is the 'shell' that the nuclei form in momentum space compared to the 'shell' formed by D2 or H2 in a gas, at room temperature? Will the distribution of momentum be more spread out or more compact, so to speak, in a...
this question might be a bit stupid, but if the plasma in the fusion reactor has very high temperature, then how do we make the chamber not melt? i mean, not to join? contact? each other(chamber wall and plasma).
do we use magnetic field to make the distance? then how do we do that?
Recently, Germany broke headlines when they fired up their nuclear fusion reactor. As I'm sure most everyone on this forum knows this, they plan on creating fusion by heating plasma to absurd temperatures while containing it in a magnetic field. What method do they use to heat the gas and...
Hello, I am a new member here at physics forums and find myself unsure of how to go about pursuing my career interest in nuclear fusion research, and if it is even something I should be pursuing at all.
My goal is to some day work in fusion research, but everyone I have talked to about this...
I was reading a paper recently about guiding electric arc discharges with lasers. http://loa.ensta-paristech.fr/ilm/uploads/ILM/134_Forestier_discharge_AIPAdvances_2_012151_2012.pdf
Since electric arcs are plasmas and they seem to be stabilized by lasers, could the same principle be applied to...
phase diagrams show the change of the state when temperature or pressure are modified. to achieve this, is necessary heat, but my questions is: would plasma state be described in this diagrams? is this figure true? because plasma state can be generated by heating.
I have been intrigued by reports over the years from witnesses who claimed (at various sites) that before a particularly severe earthquake, that unusual atmospheric phenomenon that would seem to be best described as various forms of plasma (super heated gas) were seen. Is this something accepted...
So, assume you have a plasma in a vacuum made of an even distribution of 50% electrons and 50% protons all flowing in one direction with low collision frequency. Then you suddenly turn on an external magnetic field and watch what happens. How will the plasma react?
Will the magnetic field...
Let's say we have a mol of hellium-3 and we heat it up until it becomes plasma.
What happens to the neutrons? Wikipedia does not mention anything about them. It only says that "Plasma is loosely described as an electrically neutral medium of unbound positive and negative particles". Just to make...
Hello all,
quick question: When Plasma cools what state does it return to? Is it a liquid or the state it was in before at room temperature? Do the atoms rearrange into what it was like before i.e. the same element or something completely different?
Thank you
I am going to presenting on a scientific report and the report that I choose (this can still change) is the following: http://onlinelibrary.wiley.com/doi/10.1029/2001GL013014/pdf
In this report, they ask the question of what produces what?
Does plasma flow produce an electric field?
or
Does an...
I am interested in applying plasma physics in nuclear fusion program in France or Germany . Both are good in this field , but where i can get good scholarships and i am from electrical engineering background so where i have better chance of getting admitted.
Thank you for opening my first thread.
I have just began studying Physics at a university in Hungary and would like to get some information about Physics of Complex Systems and Plasma Phyics/Nuclear Fusion.
In my life, finding a goal have always helped me work harder and focus on my studies...
Hello everyone. I am new in this forum. I am from Turkey and I want to go abroad for Ph.D. but I have concerns and a lot of questions in my mind.
My GPA from BS is 2,98/4 (I know it is not good). This year my second year my master. Probably I will graduate with 3.50-4.00 GPA. My master...
I was wondering , because all I know is that we got solid . Heat it up enough and you get liquid . Heat that up enough too and boom ! There's gas . Plasma is another transformation in this category , in this case , about heating up the gas enough . And I wanted to know , if there is anything...
I am developing a math model to describe laser ablation process considering the plasma. My supervisor want to know the exactly difference between the laser induced breakdown and laser induced plasma. After a lot search, I personally think that the 'breakdown' is the first step of plasma...
Hi,
I don't know if it's the right place for this question, but-
I need to create a satellite model, that after being in space, will come close to the atmosphere, and then go back up again. In its way up it need to use a pulsed thruster. (This needs to happen multiple times...)
Does a pulsed...
Hello,
as a software engineer I am used to having industry specific trade journals from ACM that discuss Operating systems, genetic algorithms, neural nets, etc. ...
Are there any equivalent ones for physics that covers fusion plasma and it's topics such as electromagnetism, superconductivity...
Hello,
I have been doing software engineering for over 20 years and I feel like it's time for a change before I get too ancient. I have been following and reading about plasma fusion for a number of years now and I would like to study this and be able to do some research in either a Ph.D...
Why do all wakefield accelerators seem to use either electrons or positrons? Is there any reason you would have difficulty creating a laser driven proton plasma wakefield accelerator? (that is, in comparison to an electron accelerator) Thanks.
my 3inch plasma globe needs 5V 300mA dc supply...
Can I use an adapter with 4.5V and 50mA output rating?
If can't then what will happen if I still do use it?
The reason I did not place this in the nuclear engineering forum is because I feel that it is closer to an electrical engineering problem than a nuclear engineering problem.Now to the question.
I recently got another geiger counter and a plasma globe for my birthday. Being the person I am I...
Hello.
I'm studying principle of Langmuir probe and got several questions.
1st, the textbook suddenly tells that ion density within sheath is
ni(x) = nis(Vs/V(x))1/2
where nis, Vs are ion density and plasma potential at sheath edge.
I found some document which shows that it is obtained by...
Hello,
Microwaves are classified as non-ionizing radiation, so my question is, how do microwaves separate atoms into positive ions and electrons? I've heard of multi-photon ionization, is this what happens?
Hello PF,
This has been frustrating me for a while:
The plasma inside a tokamak is being heated by current induction, which accelerates the ions and electrons in specific directions, thus the velocity of ions increase. These ions collide with each other, eventually randomizing the motion. Now...
Hello I am looking to pursue a master or Ph.D in plasma physics focusing on fusion tokamak reactors.
I have an undergrad in Comp Sci and am starting the necessary physics work to apply to grad school. Besides electromagnetics, are there other areas I should focus on?
What are the best websites...
Hi, I curoius if there is any way to hold plasma into one spherical ball intead of donut as seen in tokamak using magnetic field? I have came up with a few design but it doesn't seem to do it.
Thank you.
I know
Blood=plasma+blood corpuscles
blood corpuscles=WBC +RBC+Platelets
plasma=serum+clotting factors
But I am not sure about lymph
is lymph equal to plasma+WBC
i.e lymph=plasma +WBC
Hello, this is my first post, i only have what we call an O Level Physics here in the UK, but i have a strong layperson's interest in the subject, so I'm looking forward to picking the brains of the more educated people here.
My friend's professor showed him something very interesting, all to...
Hi there, I have some questions about plasma I wonder is it possible to use another gas (not inert gases) ?. and where i can find more information of plasma jet ? because it's almost have a copyright.
Thank you.
I've been reading some about the ITER project, tokamaks, and other approaches to plasma containment. Why can't ion trapping approaches such as an orbitrap be used for fusion plasma containment?
Homework Statement
In a so called z-pinch the plasma is determined by:B =B0r/a θ^
where a is the pinch radius
Calculate the drift velocity due a inhomogenous magnetic field and a bended magnetic field in ions with charge q and mass M in the pinch. Assume that that the ions in the plasma has...
hello
I was good in physics and chemistry at school and I have relatively good pre-university knowledge
but I never read about plasma
which book is complete enough starting from the beginning and mentioning plasma?
none of my physics or chemistry books mentioned plasma and it's really...
Hi guys, having a hard time figuring out where to start on a plasma physics related problem.
Homework Statement
An infinitely long metallic cylinder with a radius of ##r_0## is immersed in a Maxwellian plasma. An electric potential, ##\phi_0##, is applied to the cylinder. Assuming that the...
I just cannot confirm which one exist in my process. how can you differentiate between plume behavior and its interaction with laser from the ones with plasma?
Thanks in adnvance
Hello
Two temperatures state in non-equilibrium plasma has different vibrational temperature and translational temperature. Vibrational temperature is more than translational temperature usually. Help me to find a book or article for describing thermodynamics of this state.
Hi there,
So I have two questions really.
My first question is, I'm having a bit of trouble finding which books I should get to teach myself plasma physics. My school doesn't offer a course on the subject, sadly, so I asked my professors, who do nuclear research, and they didn't know which...
I am interested in adding simultaneously O2 and H2 in a magnetron sputtering discharge ignited in Ar at a pressure of 3*10-2 mbar. The discharge is driven by a RF generator (13.56 MHz, 60 - 120W). The target is W. Can anyone told me if I can expect at any explsion to apear due to simultanoously...
I was curious about why the plasma inside a modern fusion reactor (ITER, DIII-D) is modeled with a D-shaped cross section.
From what I've read, it is more stable that way, but WHY is it more stable than a similar plasma flow with a circular cross-section?
Thanks in advance (and sorry if I...
I think that this goes in this category...
Do you know if anyone is doing current work on plasma railguns? The most recent stuff that I've seen about it is still some years old.