A Re-Examination of Spheromak Experiments and Opportunities

Hooper, E. B.; Hammer, J.H.; Barnes, Cris W.; Fernández, Juan; Wysocki, F.J.

doi:10.13182/fst96-a30706

Cited by 25 publications

(17 citation statements)

References 37 publications

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“…This is not at all consistent with observations based on heat confinement in CTX that time-averaged fluctuations involved in heat transport during field decay are many orders of magnitude weaker than this (a time-averaged "free energy" of order S-r = 10-r in experiments) [7].…”

contrasting

confidence: 82%

Gun requirements to achieve high field spheromaks

Fowler¹

1999

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contrasting

confidence: 82%

Gun requirements to achieve high field spheromaks

Fowler¹

1999

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“…It has been suggested that although the global confinement time of spheromaks is not attractive for a fusion reactor, it is possible that core confinement is very good. 27 The fact that 11 T e~ 400 eV and that hard X rays 28 were observed in decaying CTX spheromaks suggests good core confinement during decay. However, this observation raises the following question: Why was good confinement not observed during sustainment?…”

Section: Proposed Experimentsmentioning

confidence: 99%

Spheromak Experiment Using Separate Guns for Formation and Sustainment

Brown

Martin

1996

Fusion Technology

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An experiment is described that incorporates the use of separate magnetized plasma guns for formation and sustainment of a spheromak. It is shown that energy coupling efficiency approaches unity if the gun and spheromak are of comparable size. A large gun should be able to operate at lower current and therefore lower voltage. In addition, it is expected that a gun matched to the size of the spheromak will cause less perturbation to the equilibrium. It is proposed to use a smaller gun for spheromak formation and a large, efficient gun for sustainment. The theoretical basis for the experiment is developed, and the details of the experiment are described. A prediction of the equilibrium magnetic flux surfaces using the EFIT code is presented.

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“…[3][4][5][6] The robustness of forming a spheromak in the laboratory using a variety of helicity injection schemes 7 is another potential advantage over more complicated and expensive setup for q Ͼ 1 devices such as tokamaks and stellerators. [3][4][5][6] The robustness of forming a spheromak in the laboratory using a variety of helicity injection schemes 7 is another potential advantage over more complicated and expensive setup for q Ͼ 1 devices such as tokamaks and stellerators.…”

Section: Introductionmentioning

confidence: 99%

Reactor prospect of spheromak concept by electrostatic helicity injection

Tang

Boozer

2008

Physics of Plasmas

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The highest performing spheromaks in the laboratory are formed by electrostatic helicity injection. Discharges with up to 1MA plasma current and core electron temperature as high as 500eV have been recently obtained. For such a scheme to scale-up to a reactor, however, a much higher current multiplication factor (plasma current over injector current) must be achieved. It is shown here that spheromak current multiplication is linearly proportional to flux amplification (ratio of poloidal fluxes inside and outside the separatrix of the mean field). Hence, spheromak optimization is centered around achieving high flux amplification, which is provided by linear or nonlinear resonant coupling between helicity injector and the spheromak force-free eigenmode. The nonlinear resonant field amplification is the most promising route to high flux amplification in a realistic plasma that often significantly deviates from the Taylor state. Accessing such nonlinear resonant field amplification can be facilitated by auxiliary current drive around the magnetic axis and auxiliary heating to break the electron temperature constraint on flux amplification.

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A Re-Examination of Spheromak Experiments and Opportunities

Cited by 25 publications

References 37 publications

Gun requirements to achieve high field spheromaks

Gun requirements to achieve high field spheromaks

Spheromak Experiment Using Separate Guns for Formation and Sustainment

Reactor prospect of spheromak concept by electrostatic helicity injection

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