Plasma Definition and 681 Threads

The paper is "Helium-like ions as powerful X-ray plasma diagnostics" Proceedings of “X-ray Astronomy 2000”, Palermo, Sep. 2000 ASP Conference Series, Vol. TBD (in press), 2001 R. Giacconi, L. Stella, S. Serio [Mentors note: arXiv link at https://arxiv.org/abs/astro-ph/0012218v2] By the way, why...

During the derivation of the dielectric function of a plasma (Kittel 8. ed. chap. 14), this somewhat mysterious quantity ε(∞) is inserted to account for the high-frequency dielectric contribution of the ionic background. In some ways, I see how this is related to the "external" charge density in...

I am trying to wrap my head around the concepts in fusion. They talk about ion density, but I don't ever see that expressed in pascals, for instance. Why is that? I understand that confinment time is also important for successful fusion and that they go hand in hand, but I'm not concerned about...

Plasma-powered rockets could reduce the travel time to Mars by roughly half. https://theconversation.com/traveling-to-mars-with-immortal-plasma-rockets-58705

Hi guys. I'm a third year physics student. Next year I'll be in my final year. I'm interested in studying fusion in the future. Unfortunately I have not done plasma physics as part of my degree so I don't know much about it yet. However I'd like to do an internship abroad this summer. Ideally I...

Summary:: I am looking for topics to give a presentation on. Hi everyone. If this is in the wrong section feel free to move it. Anyway, as part of our lab course, on top of doing experiments we will also have to prepare a 20 minute presentation on a chosen topic on physics. This is not like...

As the title indicates, what are some soft skills needed (math/programming/cfd softwares) do I need if I wish to pursue a masters degree in plasma/fusion physics? Also, how do you think I should go about learning them? Thank you.

I have observed a layer like structure (made of plasma) in a cold plasma and wonders what causes it. Following image shows the observation.

Hi, I have been taught that quarks don't exist individually on their own, as they has with be with at least another antiquark to form a colorless state. But in the quark-gluon plasma, do we have individual quarks in a color state or do they still, somehow, are in a color-neutral state? Thanks!

Just a question that's been bugging ,me, In the first seconds of the universe it is stated that a hot plasma was the seed of the universe, can some one please tell me how the plasma got hot in the fist instance. thanks.

Is it the same as the plasma density ? Is it directly proportional to the plasma density ? Does this term only applies to electropositive plasma or applies to any plasma?

∇p=j×B (eq. 1) K=nI BSolenoid=μnI⇒μK (eq. 2) ∇p=-2p0r/(a2) (eq. 3) Combining these three equations: j=-2p0r/(a2μK) (θ hat direction) Feel like this is too simple and might be missing a step any help would be much appreciated!

a) I know the invariants are $\mu = \frac{0.5*m*v_{perp}^2{B} $ and $J = v_{parallel} x b) I used the invariance of $\mu$ to get the following equation: $$ v_{perp}^2 = v_{perp,0}^2(1+\alpha(t)^2 z^2) $$ I am thinking of using the Lorentz force to get $v_z$, but I'm not so clear on how to go...

As B increases, a circular E-field is setup by Faraday's Law, which accelerates the ions/electrons into a gyrating motion. The gyrating electrons/ions have an effective magnetic moment that opposes the applied B-field (Lenz's Law). When the B-field is decreased, a circular induced E-field...

I am skeptical about the scientific basis of "platelet-rich plasma" (PRP): the view expressed in https://www.painscience.com/articles/platelet-rich-plasma-does-it-work.php seems to sum up my objections, but as I am not in the medical field, I am not sure how valid such articles as...

A simple question, I read that the particles in a plasma (protons , electrons) travel along the B field lines in a plasma which I know and they loop around the field lines each in opposite direction (clockwise, anticlockwise ) but both in the same direction. My question then is this. If I have...

From time to time I think about such ideas among other things. I know the Penning trap and I see it is a good device for catching small to medium quantities of particles with similar charge. So I thought a little how would one create something similar but for a neutral or quasi neutral plasma...

If we assume ##\nabla \times \vec{H} = \vec{0}## (again I have no idea why this would be true) $$\vec{0} = \sigma \vec{E} + \epsilon \frac{\partial \vec{E}}{\partial t}$$ $$\vec{0} = \sigma \vec{E} + \epsilon Nq\frac{\partial \vec{V}}{\partial t}$$ $$-\sigma \vec{E} = \epsilon...

Hello, just wanted to know what is recommended after undergrad Physics to get into a career developing electric propulsion systems, or anything to do with Plasmas and future propulsion devices?

Hello, I am currently working through an introductory textbook on plasma physics, and I have encountered two topics that I separately understand but seem to be at odds with one another. In a quasi neutral plasma in steady state, the following relation must hold, $$\Gamma_i = \Gamma_e.$$ In...

Summary: Is it the same as Bohm velocity ? Is it the same as Bohm velocity ?

I'm thinking of implementing a metal disk-like probe in an Argon plasma which is powered by RF. Therefore I need to know a metal that's least reactive with the plasma. Does molybdenum meets this requirement?

Summary: I'm interested in knowing more about instabilities within plasma. Is the viscosity of plasma produced by thermal, magnetic, or gravitational effects (or even something else)? I had the opportunity to talk with multiple Ph.D. students during the summer and was especially interested in...

Hi, of all the main plasma heating techniques employed by multiple fusion reactor designs, namely 1) ohmic heating 2)RF 3)neutral beam 4)some other method? Which of them is the most efficient in terms of how much of the input electricity gets converted to direct heat/kinetic energy of the...

Homework Statement: So if I were to take Jew strong very strong magnets and place them repelling one another in a vacuum would I be able to create plasma and could I create a laser that can shoot it out? Homework Equations: sorry new to this :biggrin:

Summary: specific modulation of lasers will cause ionisation, how is this being used in plasma physics? Just a simple question

Principles of Plasma physics by Krall & Trivelpiece seems to be a well-used book in the plasma physics community, but I've never seen a solution key for the questions asked in the book. I am trying some of the problems and want to check my work. Is there such a solution key or some blog that...

If we heat up hydrogen gas in a sealed container to tens of thousands of degrees Celsius (via microwave or other radiation) , until the nucleus and electrons start to separate from each other, which becomes plasma. Then use a polarised magnetic field to separate the protons and electrons. Where...

I have no clear idea of this phenomenon?

Summary: I was reading that the most powerful gamma ray burst experienced a 'drag' due to quantum turbulence and wondered how this could effect a plasma. After reading this Wikipedia article https://en.wikipedia.org/wiki/GRB_080916C I noticed the part about how the light was slowed down by the...

If i get this right: In space when electrons leave its atoms, do they attach to something else? Or is the electrons bouncing freely in space when they get detached? Is this because of dark energy? And if so, where do they go? Do they move between atoms or are the free to go anywhere? And where...

The following physical expression : Collisionless plasma hydromagnetic waves. What does it mean?

I was looking at things today and read (on wiki) that the use of Thompson Scattering reveals electron temperature in a plasma, not ion temperature. I thought that's how ion temp was measured (or maybe it is and the wiki text was incomplete)? Could someone please clarify how ion temperatures in...

Plasma balls. Knowing that... 1. Neon lights are filled with noble gas and light up when current goes through them. 2. The equations, ##V=Ed##, ##F=qE ##, and Coulomb's Law could be used to design these. Are you actually seeing a random electric field or is the plasma real...

I read Wikipedia's description of how a plasma ball works. Question: What kind of energy is the "radio-frequency energy from the transformer"? Is in the form of electric field energy, magnetic field energy, or both? Thank you! (from Wikipedia)... Although many variations exist, a plasma lamp is...

Hi, I've posted here several time because you all gave me very helpful suggestions. Let me recap briefly my situation. I apologize for the very long post. I have BS in chemical engineering but now I'm going through a MS degree in nuclear engineering. Although - given my background - I should...

Background of problem comes from Drude model of a metal (not necessary to answer my problem but for the curious): Consider a uniform, time-dependent electric field acting on a metal. It can be shown that the conductivity is $$\sigma = \frac{\sigma_0}{1-i\omega t}$$ where $$\sigma_0 =...

https://arxiv.org/abs/1512.06471 In the paper, dark plasma (that is, NOT baryonic plasma) was suggested. I'd like to know if it is compatible with many cosmic phenomena (like bullet clusters). Can you think of one where the data (especially new ones) don't support it? In baryonic matter...

It is my understanding that a state of matter known as quark-gluon plasma has been produced artificially and studied in various labs. How is the presence of varying densities of charged leptons such as electrons thought to influence the behavior of any naturally occurring examples of quark gluon...

I'm an undergraduate student and thinking of doing a research in plasma physics. Any suggestion? I prefer to do it computationally. Most research topic in plasma physics I googled are about fusion, but do you think it's too advanced for my education level?

I will make some assertions and then phrase a question , please correct me if necessary. So the tokamak works like a transformer where the primary is a coil winding while the secondary is a torus which contains plasma which being electrically conductive forms the secondary winding? The toroidal...

Hi, I am interested in plasma physics. I understand that once a gas (say Argon) is ionized, light (electromagnetic radiation) is emitted. This is clearly observable from the coloured glow of the gas when it is in a plasma state. Where does the energy for these electromagnetic rays come from? Is...

Hi, I was wondering of those who might write papers in this field. What is the convention of units in plasma physics papers, and is this often all screwed around and you have to already understand it to understand it? I'll give you an example, because I am looking at this paper to understand...

Hello all: I was wondering what is the shape of the plasma at Nif ,is it spherical ? I start to wonder that it may be spindle shaped ,or fusiform shaped . Best H

https://phys.org/news/2019-01-scientists-stabilizes-fusion-plasmas.html By applying more RF power to the unstable 'bubbles' that form in the plasmas.

I'm trying to understand the physical implications of electron temperature (Te), vibrational temperature (Tv), rotational temperature (Tr) and translational temperature (To) of a plasma. I am reading often that Te > Tv > Tr ≃To, in terms of what is happening inside the plasma what does this...

Could there be a connection between Robert Zimmermann's work (McMaster Univ. Toronto) on Vector Plasma, and Jenkins and Fischbach's (Perdue Univ.) work on variations in the rate of radioactive decay for elements on Earth in relation to solar activity? Only looking for a confirmation that their...

Hello, I am having a very hard time understanding what is plasma frequency by reading definitions. I know, for example, that metals have a metallic bond and can be analysed like plasma because of an equal distribution of electrons in electron gas and positively charged atoms. I know metals are...

Let us say that we have a dispersion relation curve and associated instability curve as shown below for a magnetised plasma, which have been formulated through kinetic theory. The frequencies and growth rate have been normalized w.r.t. cyclotron frequency of proton. My question is: what does...

In plasma physics we have what is known as plasma dispersion function. There are two approximation under which this function can be expanded: when the argument is less than 1, we can use power series expansion and when the argument is greater than 1 we can have asymptotic expression. My...