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Title: Thermonuclear inverse magnetic pumping power cycle for stellarator reactors

Abstract

A novel power cycle for direct conversion of alpha-particle energy into electricity is proposed for an ignited plasma in a stellarator reactor. The plasma column is alternately compressed and expanded in minor radius by periodic variation of the toroidal magnetic field strength. As a result of the way a stellarator is expected to work, the plasma pressure during expansion is greater than the corresponding pressure during compression. Therefore, negative work is done on the plasma during a complete cycle. This work manifests itself as a back-voltage in the toroidal field coils, and direct electrical energy is obtained from this voltage. For a typical reactor, the average power obtained from this cycle (with a minor radius compression factor on the order of 50%) can be as much as 50% of the electrical power obtained from the thermonuclear neutrons without compressing the plasma. Thus, if it is feasible to vary the toroidal field strength, the power cycle provides an alternative scheme of energy conversion for a deuterium-tritium fueled reactor. The cycle may become an important method of energy conversion for advanced neutron-lean fueled reactors. By operating two or more reactors in tandem, the cycle can be made self-sustaining.

Authors:
;
Publication Date:
Research Org.:
Princeton Univ., NJ (USA). Plasma Physics Lab.
OSTI Identifier:
5138614
Report Number(s):
PPPL-2249
ON: DE86002539
DOE Contract Number:
AC02-76CH03073
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; STELLARATOR TYPE REACTORS; ENERGY CONVERSION; ALPHA PARTICLES; ELECTRIC POTENTIAL; MAGNETIC FIELD CONFIGURATIONS; MAGNETIC-PUMPING HEATING; PLASMA PRESSURE; CHARGED PARTICLES; CONVERSION; HEATING; HIGH-FREQUENCY HEATING; PLASMA HEATING; THERMONUCLEAR REACTORS; 700207* - Fusion Power Plant Technology- Power Conversion Systems

Citation Formats

Ho, D.D.M., and Kulsrud, R.M.. Thermonuclear inverse magnetic pumping power cycle for stellarator reactors. United States: N. p., 1985. Web. doi:10.2172/5138614.
Ho, D.D.M., & Kulsrud, R.M.. Thermonuclear inverse magnetic pumping power cycle for stellarator reactors. United States. doi:10.2172/5138614.
Ho, D.D.M., and Kulsrud, R.M.. Sun . "Thermonuclear inverse magnetic pumping power cycle for stellarator reactors". United States. doi:10.2172/5138614. https://www.osti.gov/servlets/purl/5138614.
@article{osti_5138614,
title = {Thermonuclear inverse magnetic pumping power cycle for stellarator reactors},
author = {Ho, D.D.M. and Kulsrud, R.M.},
abstractNote = {A novel power cycle for direct conversion of alpha-particle energy into electricity is proposed for an ignited plasma in a stellarator reactor. The plasma column is alternately compressed and expanded in minor radius by periodic variation of the toroidal magnetic field strength. As a result of the way a stellarator is expected to work, the plasma pressure during expansion is greater than the corresponding pressure during compression. Therefore, negative work is done on the plasma during a complete cycle. This work manifests itself as a back-voltage in the toroidal field coils, and direct electrical energy is obtained from this voltage. For a typical reactor, the average power obtained from this cycle (with a minor radius compression factor on the order of 50%) can be as much as 50% of the electrical power obtained from the thermonuclear neutrons without compressing the plasma. Thus, if it is feasible to vary the toroidal field strength, the power cycle provides an alternative scheme of energy conversion for a deuterium-tritium fueled reactor. The cycle may become an important method of energy conversion for advanced neutron-lean fueled reactors. By operating two or more reactors in tandem, the cycle can be made self-sustaining.},
doi = {10.2172/5138614},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Sun Sep 01 00:00:00 EDT 1985},
month = {Sun Sep 01 00:00:00 EDT 1985}
}

Technical Report:

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  • This patent describes the plasma column in a stellarator is compressed and expanded alternatively in minor radius. First a plasma in thermal balance is compressed adiabatically. The volume of the compressed plasma is maintained until the plasma reaches a new thermal equilibrium. The plasma is then expanded to its original volume. As a result of the way a stellarator works, the plasma pressure during compression is less than the corresponding pressure during expansion. Therefore, negative work is done on the plasma over a complete cycle. This work manifests itself as a back-voltage in the toroidal field coils. Direct electrical energymore » is obtained from this voltage. Alternatively, after the compression step, the plasma can be expanded at constant pressure.« less
  • The plasma column in a stellarator is compressed and expanded alternatively in minor radius. First a plasma in thermal balance is compressed adiabatically. The volume of the compressed plasma is maintained until the plasma reaches a new thermal equilibrium. The plasma is then expanded to its original volume. As a result of the way a stellarator works, the plasma pressure during compression is less than the corresponding pressure during expansion. Therefore, negative work is done on the plasma over a complete cycle. This work manifests itself as a back-voltage in the toroidal field coils. Direct electrical energy is obtained frommore » this voltage. Alternatively, after the compression step, the plasma can be expanded at constant pressure. The cycle can be made self-sustaining by operating a system of two stellarator reactors in tandem. Part of the energy derived from the expansion phase of a first stellarator reactor is used to compress the plasma in a second stellarator reactor.« less
  • The plasma column in a stellarator is compressed and expanded alternatively in minor radius. First a plasma in thermal balance is compressed adiabatically. The volume of the compressed plasma is maintained until the plasma reaches a new thermal equilibrium. The plasma is then expanded to its original volume. As a result of the way a stellarator works, the plasma pressure during compression is less than the corresponding pressure during expansion. Therefore, negative work is done on the plasma over a complete cycle. This work manifests itself as a back-voltage in the toroidal field coils. Direct electrical energy is obtained frommore » this voltage. Alternatively, after the compression step, the plasma can be expanded at constant pressure. The cycle can be made self-sustaining by operating a system of two stellarator reactors in tandem. Part of the energy derived from the expansion phase of a first stellarator reactor is used to compress the plasma in a second stellarator reactor. 9 figs., 4 tabs.« less
  • Results are summarized from a study of the B-2 magnetic pumping section, commonly called the B-2 Bulge, using the axially symmetric resistance analogue. The limiting aperture is found for all values of M, the pumping modulus, from zero to 1.00, taken in steps of 0.05. The radius of the limiting flux line is given for seven axially spaced points within the bulge. This radius was found for the instants in time when the R-F current is peak negatmve, peak positive, and zero. The location of the limiting flux line for M = 0.85 was determined as a function of time.more » For comparison, the time-dependent location of the flux line having one-fourth the value of the limiting flux line is also shown, again for M = 0.86. Empirical formulas are given enabling a determination of the value of the flux line at any radius (at any of the seven axial positions) for any instant of time and any value of M. Conversely, through a process of iteration, the formulas may be used to find the radius of a given flux line, again for any instant of time and value of M. (auth)« less