Confinement transport
Download
1 / 21

Confinement & Transport - PowerPoint PPT Presentation


  • 94 Views
  • Uploaded on

Confinement & Transport. 29-11-2010. Plan. Classical theory of confinement and transport. Diffusion equation Particle diffusion in a magnetic field Diffusion as a random walk Collisions in a fully magnetized plasmas Heat diffusion What happens in a real tokamak?. Bibliography.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' Confinement & Transport' - medea


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

Plan

  • Classical theory of confinement and transport.

  • Diffusion equation

  • Particle diffusion in a magnetic field

  • Diffusion as a random walk

  • Collisions in a fully magnetized plasmas

  • Heat diffusion

  • What happens in a real tokamak?


Bibliography
Bibliography

  • F. Chen: Introduction to plasma physics, pages 165 to 181

  • Freidberg: Plasma physics and fusion energy Chapter 14


Energy confinement in magnetically confined plasma
Energy confinement in magnetically confined plasma

  • L and H modes in tokamak

  • H modes exist also in stellarator


Iter plasma scenario elmy h mode
ITER Plasma Scenario - ELMy H-mode

From D. Campbell-ITER

  • Conventionally, plasma confinement regimes denoted L-mode and H-mode

    • The difference between these modes is caused by the formation of an edge pedestal in which transport is significantly reduced - edge transport barrier

    • edge localized modes maintain plasma in quasi-stationary state

JET




H mode 1
H mode (1)

  • Excerpt from Wesson -Tokamaks



Spectre
Spectre

hn= 13.6 eV = Energie d’ionisation

Extrait de Spectroscopy;

Edité par B.P. Straughna et S. Walker; Science Paperbacks




Degradation of confinement with density
Degradation of confinement with density

Nuclear Fusion, Vol 47, Number 6 June 2007


Iter baseline scenario elmy h mode
ITER Baseline Scenario - ELMy H-mode

From D. Campbell-ITER

  • The ELMy H-mode is a robust mode of tokamak operation - ITER baseline scenario

    • H-mode confinement time is approximately double that in L-mode

    • multi-machine database provides scaling prediction for ITER energy confinement time

th IpR2P-2/3

JET




Internal barrier
Internal barrier

From D. Campbell-ITER


Discovery of internal transport barriers “advanced scenarios”

From D. Campbell -ITER

Steady-State Operation

plasma with reversed central shear +sufficient rotational shear

internal transport barrier  enhanced confinement

reduced current operation +large bootstrap current fraction

active mhd control

reduced external current drive +current well aligned for mhd stability and confinement enhancement

Steady-state operation +High fusion power density

  • But development of an integrated plasma scenario satisfying all reactor-relevant requirements remains challenging


Quiz to summarize a few important points
Quiz to summarize a few important points

  • Is the diffusion equation symmetric with respect to time? According to you, what is the meaning of this non symmetry?

  • What is the dependency of the classical diffusion coefficient with respect to the magnetic field?

  • What are the two main confinement modes in a magnetically confined plasma?

  • How does one get the H mode?


ad