Book contents
- Frontmatter
- Contents
- Preface
- 1 Introduction
- 2 Current-Sheet Formation
- 3 Magnetic Annihilation
- 4 Steady Reconnection: The Classical Solutions
- 5 Steady Reconnection: New Generation of Fast Regimes
- 6 Unsteady Reconnection: The Tearing Mode
- 7 Unsteady Reconnection: Other Approaches
- 8 Reconnection in Three Dimensions
- 9 Laboratory Applications
- 10 Magnetospheric Applications
- 11 Solar Applications
- 12 Astrophysical Applications
- 13 Particle Acceleration
- References
- Appendix 1 Notation
- Appendix 2 Units
- Appendix 3 Useful Expressions
- Index
9 - Laboratory Applications
Published online by Cambridge University Press: 14 October 2009
- Frontmatter
- Contents
- Preface
- 1 Introduction
- 2 Current-Sheet Formation
- 3 Magnetic Annihilation
- 4 Steady Reconnection: The Classical Solutions
- 5 Steady Reconnection: New Generation of Fast Regimes
- 6 Unsteady Reconnection: The Tearing Mode
- 7 Unsteady Reconnection: Other Approaches
- 8 Reconnection in Three Dimensions
- 9 Laboratory Applications
- 10 Magnetospheric Applications
- 11 Solar Applications
- 12 Astrophysical Applications
- 13 Particle Acceleration
- References
- Appendix 1 Notation
- Appendix 2 Units
- Appendix 3 Useful Expressions
- Index
Summary
Reconnection is not difficult to achieve in a laboratory environment. When two simple dipole magnets are held near each other in air, two null points will generally be present, and when the magnets are moved relative to each other, their field lines easily reconnect. It is only when a conducting plasma is present in the vicinity of a null point that reconnection starts to become difficult and therefore interesting.
The principal application of reconnection theory in the laboratory has been in the development of magnetic containment devices for controlled thermonuclear fusion, but plasma experiments have also been designed specifically to study reconnection dynamics. Containment devices try to confine a sufficiently hot plasma inside a magnetic bottle for a period long enough to achieve a sustained nuclear reaction. Reconnection can both hinder and help in this regard. For example, in one device (known as the tokamak, §9.1.2) reconnection is involved in several different instabilities which degrade the confinement, but in another device (known as the spheromak, §9.1.3) reconnection is necessary to create the field configuration which actually confines the plasma.
Laboratory experiments specifically designed to study reconnection dynamics are motivated by a desire to understand reconnection as a general physical process, in the hope that this knowledge can be applied to both fusion, space, and astrophysical applications. However, as with numerical simulations, laboratory experiments cannot easily replicate the conditions that occur outside the Earth, primarily because of the problem of scale. Laboratory devices typically have dimensions of a metre or less, which is many orders of magnitude smaller than occurs in cosmical applications.
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- Magnetic ReconnectionMHD Theory and Applications, pp. 290 - 321Publisher: Cambridge University PressPrint publication year: 2000
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