skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: The ''Kinetic Stabilizer'': A Simpler Tandem Mirror Confinement?

Abstract

In the search for better approaches to magnetic fusion it is important to keep in mind the lessons learned in the 50 years that fusion plasma confinement has been studied. One of the lessons learned is that ''closed'' and ''open'' fusion devices differ fundamentally with respect to an important property of their confinement, as follows: Without known exception closed systems such as the tokamak, the stellarator, or the reversed-field pinch, have been found to have their confinement times limited by non-classical, i.e., turbulence-related, processes, leading to the requirement that such systems must be scaled-up in dimensions to sizes much larger than would be the case in the absence of turbulence. By contrast, from the earliest days of fusion research, it has been demonstrated that open magnetic systems of the mirror variety can achieve confinement times close to that associated with classical, i.e., collisional, processes. While these good results have been obtained in both axially symmetric fields and in non-axisymmetric fields, the clearest cases have been those in which the confining fields are solenoidal and axially symmetric. These observations, i.e., of confinement not enhanced by turbulence, can be traced theoretically to such factors as the absence of parallel currents in themore » plasma, and to the constraints on particle drifts imposed by the adiabatic invariants governing particle confinement in axisymmetric open systems. In the past the MHD instability of axially symmetric open systems has been seen as a barrier to their use. However, theory predicts MHD-stable confinement is achievable if sufficient plasma is present in the ''good curvature'' regions outside the mirrors. This theory has been confirmed by experiments on the Gas Dynamic Trap mirror-based experiment at Novosibirsk, In this paper a new way of exploiting this stabilizing principle, involving creating a localized ''stabilizer plasma'' outside a mirror, will be discussed. To create this plasma ion beams are injected along the field lines in such a way as to be reflected before they reach the mirrors, thus forming a localized peak in the plasma density. It will be shown that the power required to produce these stabilizing plasmas is much less than the power per meter of fusion power systems that might employ this technique. Use of the Kinetic Stabilizer idea may therefore permit the construction of tandem mirror fusion power systems that are much smaller and simpler than those based on the use of non-axisymmetric fields to achieve MHD stability.« less

Authors:
Publication Date:
Research Org.:
Lawrence Livermore National Lab., Livermore, CA (US)
Sponsoring Org.:
USDOE Office of Defense Programs (DP) (US)
OSTI Identifier:
791326
Report Number(s):
UCRL-JC-139277
TRN: US0501998
DOE Contract Number:  
W-7405-Eng-48
Resource Type:
Conference
Resource Relation:
Conference: Open Magnetic Systems for Plasma Confinement, Tsukuba (JP), 07/03/2000--07/06/2000; Other Information: PBD: 15 Jun 2000
Country of Publication:
United States
Language:
English
Subject:
24 POWER TRANSMISSION AND DISTRIBUTION; 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; CONFINEMENT; CONFINEMENT TIME; CONSTRUCTION; DIMENSIONS; INSTABILITY; ION BEAMS; KINETICS; MIRRORS; PLASMA CONFINEMENT; PLASMA DENSITY; POWER SYSTEMS; STABILITY; TANDEM MIRRORS; TURBULENCE

Citation Formats

Post, R F. The ''Kinetic Stabilizer'': A Simpler Tandem Mirror Confinement?. United States: N. p., 2000. Web.
Post, R F. The ''Kinetic Stabilizer'': A Simpler Tandem Mirror Confinement?. United States.
Post, R F. Thu . "The ''Kinetic Stabilizer'': A Simpler Tandem Mirror Confinement?". United States. https://www.osti.gov/servlets/purl/791326.
@article{osti_791326,
title = {The ''Kinetic Stabilizer'': A Simpler Tandem Mirror Confinement?},
author = {Post, R F},
abstractNote = {In the search for better approaches to magnetic fusion it is important to keep in mind the lessons learned in the 50 years that fusion plasma confinement has been studied. One of the lessons learned is that ''closed'' and ''open'' fusion devices differ fundamentally with respect to an important property of their confinement, as follows: Without known exception closed systems such as the tokamak, the stellarator, or the reversed-field pinch, have been found to have their confinement times limited by non-classical, i.e., turbulence-related, processes, leading to the requirement that such systems must be scaled-up in dimensions to sizes much larger than would be the case in the absence of turbulence. By contrast, from the earliest days of fusion research, it has been demonstrated that open magnetic systems of the mirror variety can achieve confinement times close to that associated with classical, i.e., collisional, processes. While these good results have been obtained in both axially symmetric fields and in non-axisymmetric fields, the clearest cases have been those in which the confining fields are solenoidal and axially symmetric. These observations, i.e., of confinement not enhanced by turbulence, can be traced theoretically to such factors as the absence of parallel currents in the plasma, and to the constraints on particle drifts imposed by the adiabatic invariants governing particle confinement in axisymmetric open systems. In the past the MHD instability of axially symmetric open systems has been seen as a barrier to their use. However, theory predicts MHD-stable confinement is achievable if sufficient plasma is present in the ''good curvature'' regions outside the mirrors. This theory has been confirmed by experiments on the Gas Dynamic Trap mirror-based experiment at Novosibirsk, In this paper a new way of exploiting this stabilizing principle, involving creating a localized ''stabilizer plasma'' outside a mirror, will be discussed. To create this plasma ion beams are injected along the field lines in such a way as to be reflected before they reach the mirrors, thus forming a localized peak in the plasma density. It will be shown that the power required to produce these stabilizing plasmas is much less than the power per meter of fusion power systems that might employ this technique. Use of the Kinetic Stabilizer idea may therefore permit the construction of tandem mirror fusion power systems that are much smaller and simpler than those based on the use of non-axisymmetric fields to achieve MHD stability.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2000},
month = {6}
}

Conference:
Other availability
Please see Document Availability for additional information on obtaining the full-text document. Library patrons may search WorldCat to identify libraries that hold this conference proceeding.

Save / Share: