VIDEOS 1 TO 50

2b Coulomb collisions in plasmas

Published: 2015/09/15

Channel: Plasma Physics and Applications

14A Coulomb Collisions | Introduction to Plasma Physics by J D Callen

Published: 2015/12/24

Channel: Lucius Fox

Coulomb collision Meaning

Published: 2015/04/22

Channel: SDictionary

collision response with coulomb friction

Published: 2013/03/23

Channel: Glenn Fiedler

Special collision between 2 Protons entering inside the range of strong Coulomb force

Published: 2010/08/17

Channel: Bengt Nyman

1 Solution (1/2) Problem #25 - Collision 1000 GeV Proton

Published: 2018/02/02

Channel: Lectures by Walter Lewin. They will make you ♥ Physics.

Robust Treatment of Simultaneous Collisions

Published: 2012/12/26

Channel: Walt Disney Animation Studios

Proton collision and penetration into the range of strong Coulomb force

Published: 2010/10/08

Channel: Bengt Nyman

Big Balls! Thermal Energy in Collisions

Published: 2017/10/14

Channel: A Level Physics Online

Collision Detection and Response - Interactive 3D Graphics

Published: 2015/02/23

Channel: Udacity

Electric Charges: "Coulomb's Law" 1959 PSSC; Eric Rogers; Princeton University

Published: 2017/05/18

Channel: Jeff Quitney

Electron collision

Published: 2007/11/15

Channel: arthurnal

Physics 30: Lesson 13 - Elastic and Inelastic Collisions

Published: 2014/08/15

Channel: ms. Booth

collision response linear

Published: 2013/03/23

Channel: Glenn Fiedler

proton collision jet

Published: 2010/11/30

Channel: noxjumblebox

Coulomb's Law Overview

Published: 2013/04/14

Channel: Frank McCulley

Lec 15: Momentum and Its Conservation | 8.01 Classical Mechanics, Fall 1999 (Walter Lewin)

Published: 2014/12/10

Channel: For the Allure of Physics

Electron Capture & Proton - Electron Collisions | A-level Physics | AQA, OCR, Edexcel

Published: 2017/05/26

Channel: SnapRevise

Physics: Mechanics- Momentum (5 of 9) Momentum in 2-Dimension Explained: Graphically

Published: 2016/08/19

Channel: Michel van Biezen

2D Collision Response

Published: 2012/08/03

Channel: Jamie King

Coulomb Focusing: Helping Electrons Hit the Bullseye

Published: 2013/10/02

Channel: Aaron Parsons

Coulomb's Law - How To Calculate The Electric Force Between 3 Point Charges Physics

Published: 2017/12/06

Channel: The Organic Chemistry Tutor

Physics: "Elastic Collision and Stored Energy" 1961 PSSC; James Strickland, Energy, Momentum...

Published: 2017/06/23

Channel: Jeff Quitney

James D. Callen: Fluid and transport modeling of plasmas 1: collisional plasma kinetics, solutions

Published: 2015/08/06

Channel: Centre International de Rencontres Mathématiques

angular collision response new

Published: 2013/03/23

Channel: Glenn Fiedler

Gravity & Coulomb repulsion

Published: 2009/07/09

Channel: Computer Physics Lab

Simulation of Coulomb crystal of 2685 Ca+

Published: 2016/11/03

Channel: Thierry Matthey

Lecture 11 - Discharge physics, Gaseous electronics, mean free path, collision frequency

Published: 2017/05/22

Channel: USYD - Senior Plasma Physics Lectures

collision response rolling friction

Published: 2013/03/23

Channel: Glenn Fiedler

Elastic Collision

Published: 2017/09/21

Channel: Michael Teters

Accurate 2D collision responses

Published: 2014/04/11

Channel: Guillaume Racicot

angular collision response without friction

Published: 2013/03/23

Channel: Glenn Fiedler

N-body Simulation of Counter-streaming ion beams.

Published: 2017/08/08

Channel: Andrew Chap

8.01x - Module 18 01 Elastic collision of sliders with unequal masses, one at rest

Published: 2015/02/16

Channel: Lectures by Walter Lewin. They will make you ♥ Physics.

Elastic and inelastic Collision in one and two dimension and problems on it in hindi

Published: 2017/10/01

Channel: ARIF ACADEMY

Higgs particle production 2.Proton - proton Collision in the ATLAS Experiment

Published: 2011/05/30

Channel: portalhispano1

[量子力學]第10-1講、Collision Theory

Published: 2012/11/14

Channel: CASE 臺大科學教育發展中心

1c Plasma definition: frequencies and parameters

Published: 2015/09/15

Channel: Plasma Physics and Applications

Line 18 a3z5b3a Nuclear Fusion Collision Spin Polarized Plasmas Electron 5g WOW SETI

Published: 2012/04/13

Channel: theideagirlsays

Coulomb-Friction-Based Needle Insertion/Withdrawal Model

Published: 2010/09/03

Channel: Ryo Kikuuwe

Line 18 a3z5b5 Coulomb Barrier Nuclear Bi-sphere Fiber Laser Light Resonators 5g WOW SETI

Published: 2012/04/17

Channel: theideagirlsays

Purdue PHYS 342 L16.2: Nuclear Reactions: Fusion

Published: 2014/12/08

Channel: nanohubtechtalks

18 Coulomb Friction

Published: 2014/02/14

Channel: John Ferris

Introduction to Friction

Published: 2012/03/06

Channel: Darryl Morrell

What is Radiation Measurements (Exposure in Air)

Published: 2017/06/01

Channel: RadTechBootCamp

collision response no rotation

Published: 2016/05/15

Channel: RobotZer0

Inelastic Collisions

Published: 2017/09/21

Channel: Michael Teters

ATLAS 13 TeV Stable Beam Collisions

Published: 2015/06/08

Channel: ATLAS Experiment

Inelastic Collision Example # 1

Published: 2012/12/27

Channel: AK LECTURES

La théorie des collisions Partie 2

Published: 2016/02/24

Channel: Mme Chimie

A **Coulomb collision** is a binary elastic collision between two charged particles interacting through their own electric field. As with any inverse-square law, the resulting trajectories of the colliding particles is a hyperbolic Keplerian orbit. This type of collision is common in plasmas where the typical kinetic energy of the particles is too large to produce a significant deviation from the initial trajectories of the colliding particles, and the cumulative effect of many collisions is considered instead.

In a plasma a Coulomb collision rarely results in a large deflection. The cumulative effect of the many small angle collisions, however, is often larger than the effect of the few large angle collisions that occur, so it is instructive to consider the collision dynamics in the limit of small deflections.

We can consider an electron of charge -*e* and mass *m*_{e} passing a stationary ion of charge +*Ze* and much larger mass at a distance *b* with a speed *v*. The perpendicular force is (1/4πε_{0})*Ze*^{2}/*b*^{2} at the closest approach and the duration of the encounter is about *b*/*v*. The product of these expressions divided by the mass is the change in perpendicular velocity:

Note that the deflection angle is proportional to . Fast particles are "slippery" and thus dominate many transport processes. The efficiency of velocity-matched interactions is also the reason that fusion products tend to heat the electrons rather than (as would be desirable) the ions. If an electric field is present, the faster electrons feel less drag and become even faster in a "run-away" process.

In passing through a field of ions with density *n*, an electron will have many such encounters simultaneously, with various impact parameters (distance to the ion) and directions. The cumulative effect can be described as a diffusion of the perpendicular momentum. The corresponding diffusion constant is found by integrating the squares of the individual changes in momentum. The rate of collisions with impact parameter between *b* and (*b*+d*b*) is *nv*(2π*b* d*b*), so the diffusion constant is given by

Obviously the integral diverges toward both small and large impact parameters. At small impact parameters, the momentum transfer also diverges. This is clearly unphysical since under the assumptions used here, the final perpendicular momentum cannot take on a value higher than the initial momentum. Setting the above estimate for equal to *mv*, we find the lower cut-off to the impact parameter to be about

We can also use πb_{0}^{2} as an estimate of the cross section for large-angle collisions. Under some conditions there is a more stringent lower limit due to quantum mechanics, namely the de Broglie wavelength of the electron, *h*/(*m*_{e}*v*).

At large impact parameters, the charge of the ion is shielded by the tendency of electrons to cluster in the neighborhood of the ion and other ions to avoid it. The upper cut-off to the impact parameter should thus be approximately equal to the Debye length:

The integral of 1/*b* thus yields the logarithm of the ratio of the upper and lower cut-offs. This number is known as the **Coulomb logarithm** and is designated by either lnΛ or λ. It is the factor by which small-angle collisions are more effective than large-angle collisions. For many plasmas of interest it takes on values between 5 and 15. (For convenient formulas, see pages 34 and 35 of the *NRL Plasma formulary*.) The limits of the impact parameter integral are not sharp, but are uncertain by factors on the order of unity, leading to theoretical uncertainties on the order of 1/λ. For this reason it is often justified to simply take the convenient choice λ = 10. The analysis here yields the scalings and orders of magnitude.^{[1]}

**^**Huba, J.D. (2016).*NRL Plasma formulary*(PDF). The Office of Naval Research. pp. 31 ff.

- Effects of Ionization [ApJ paper] by Gordon Emslie
- [1] [NRL Plasma Formulary 2013 ed.]

None of the audio/visual content is hosted on this site. All media is embedded from other sites such as GoogleVideo, Wikipedia, YouTube etc. Therefore, this site has no control over the copyright issues of the streaming media.

All issues concerning copyright violations should be aimed at the sites hosting the material. This site does not host any of the streaming media and the owner has not uploaded any of the material to the video hosting servers. Anyone can find the same content on Google Video or YouTube by themselves.

The owner of this site cannot know which documentaries are in public domain, which has been uploaded to e.g. YouTube by the owner and which has been uploaded without permission. The copyright owner must contact the source if he wants his material off the Internet completely.

Wikipedia content is licensed under the GFDL and (CC) license