Dynamo-free plasma in the reversed-field pinch: Advances in understanding the reversed-field pinch improved confinement mode

J. K. Anderson; J. Adney; A. Almagri; A. Blair; D. L. Brower; M. Cengher; B. E. Chapman; S. Choi; D. Craig; D. R. Demers; D. J.Den Hartog; B. Deng; W. X. Ding; F. Ebrahimi; D. Ennis; G. Fiksel; C. B. Forest; P. Franz; J. Goetz; R. W. Harvey; D. Holly; B. Hudson; M. Kaufman; T. Lovell; L. Marrelli; P. Martin; K. McCollam; V. V. Mirnov; P. Nonn; R. O'Connell; S. Oliva; P. Piovesan; S. C. Prager; I. Predebon; J. S. Sarff; G. Spizzo; V. Svidzinski; M. Thomas; M. D. Wyman

doi:10.1063/1.1883666

Dynamo-free plasma in the reversed-field pinch: Advances in understanding the reversed-field pinch improved confinement mode

J. K. Anderson, J. Adney, A. Almagri, A. Blair, D. L. Brower, M. Cengher, B. E. Chapman, S. Choi, D. Craig, D. R. Demers, D. J.Den Hartog, B. Deng, W. X. Ding, F. Ebrahimi, D. Ennis, G. Fiksel, C. B. Forest, P. Franz, J. Goetz, R. W. HarveyD. Holly, B. Hudson, M. Kaufman, T. Lovell, L. Marrelli, P. Martin, K. McCollam, V. V. Mirnov, P. Nonn, R. O'Connell, S. Oliva, P. Piovesan, S. C. Prager, I. Predebon, J. S. Sarff, G. Spizzo, V. Svidzinski, M. Thomas, M. D. Wyman

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20 Scopus citations

Abstract

Generation and sustainment of the reversed field pinch (RFP) magnetic configuration normally relies on dynamo activity. The externally applied electric field tends to drive the equilibrium away from the relaxed, minimum energy state which is roughly described by a flat normalized parallel current density profile and is at marginal stability to tearing modes. Correlated fluctuations of magnetic field and velocity create a dynamo electric field which broadens the parallel current density profile, supplying the necessary edge current drive. These pervasive magnetic fluctuations are also responsible for destruction of flux surfaces, relegating the standard RFP to a stochastic-magnetic transport-limited device. Application of a tailored electric field profile (which matches the relaxed current density profile) allows sustainment of the RFP configuration without dynamo-driven edge current. The method used to ascertain that a dynamo-free RFP plasma has been created is reported here in detail. Several confinement improvements during the accompanying periods of low magnetic fluctuations are observed. Namely, the magnetic fluctuation level is reduced to the point where stochastic-magnetic transport is no longer the dominant process in the core and nested flux surfaces are restored in the core of the dynamo-free RFP.

Original language	English (US)
Article number	056118
Pages (from-to)	1-7
Number of pages	7
Journal	Physics of Plasmas
Volume	12
Issue number	5
DOIs	https://doi.org/10.1063/1.1883666
State	Published - May 2005

All Science Journal Classification (ASJC) codes

Condensed Matter Physics

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10.1063/1.1883666

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Anderson, J. K., Adney, J., Almagri, A., Blair, A., Brower, D. L., Cengher, M., Chapman, B. E., Choi, S., Craig, D., Demers, D. R., Hartog, D. J. D., Deng, B., Ding, W. X., Ebrahimi, F., Ennis, D., Fiksel, G., Forest, C. B., Franz, P., Goetz, J., ... Wyman, M. D. (2005). Dynamo-free plasma in the reversed-field pinch: Advances in understanding the reversed-field pinch improved confinement mode. Physics of Plasmas, 12(5), 1-7. Article 056118. https://doi.org/10.1063/1.1883666

@article{b9a35c98a83c4a26a4c0807c8cad934d,

title = "Dynamo-free plasma in the reversed-field pinch: Advances in understanding the reversed-field pinch improved confinement mode",

abstract = "Generation and sustainment of the reversed field pinch (RFP) magnetic configuration normally relies on dynamo activity. The externally applied electric field tends to drive the equilibrium away from the relaxed, minimum energy state which is roughly described by a flat normalized parallel current density profile and is at marginal stability to tearing modes. Correlated fluctuations of magnetic field and velocity create a dynamo electric field which broadens the parallel current density profile, supplying the necessary edge current drive. These pervasive magnetic fluctuations are also responsible for destruction of flux surfaces, relegating the standard RFP to a stochastic-magnetic transport-limited device. Application of a tailored electric field profile (which matches the relaxed current density profile) allows sustainment of the RFP configuration without dynamo-driven edge current. The method used to ascertain that a dynamo-free RFP plasma has been created is reported here in detail. Several confinement improvements during the accompanying periods of low magnetic fluctuations are observed. Namely, the magnetic fluctuation level is reduced to the point where stochastic-magnetic transport is no longer the dominant process in the core and nested flux surfaces are restored in the core of the dynamo-free RFP.",

author = "Anderson, {J. K.} and J. Adney and A. Almagri and A. Blair and Brower, {D. L.} and M. Cengher and Chapman, {B. E.} and S. Choi and D. Craig and Demers, {D. R.} and Hartog, {D. J.Den} and B. Deng and Ding, {W. X.} and F. Ebrahimi and D. Ennis and G. Fiksel and Forest, {C. B.} and P. Franz and J. Goetz and Harvey, {R. W.} and D. Holly and B. Hudson and M. Kaufman and T. Lovell and L. Marrelli and P. Martin and K. McCollam and Mirnov, {V. V.} and P. Nonn and R. O'Connell and S. Oliva and P. Piovesan and Prager, {S. C.} and I. Predebon and Sarff, {J. S.} and G. Spizzo and V. Svidzinski and M. Thomas and Wyman, {M. D.}",

note = "Funding Information: This work was supported by the U.S. Department of Energy and National Science Foundation. ",

year = "2005",

month = may,

doi = "10.1063/1.1883666",

language = "English (US)",

volume = "12",

pages = "1--7",

journal = "Physics of Plasmas",

issn = "1070-664X",

publisher = "American Institute of Physics Publising LLC",

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}

Anderson, JK, Adney, J, Almagri, A, Blair, A, Brower, DL, Cengher, M, Chapman, BE, Choi, S, Craig, D, Demers, DR, Hartog, DJD, Deng, B, Ding, WX, Ebrahimi, F, Ennis, D, Fiksel, G, Forest, CB, Franz, P, Goetz, J, Harvey, RW, Holly, D, Hudson, B, Kaufman, M, Lovell, T, Marrelli, L, Martin, P, McCollam, K, Mirnov, VV, Nonn, P, O'Connell, R, Oliva, S, Piovesan, P, Prager, SC, Predebon, I, Sarff, JS, Spizzo, G, Svidzinski, V, Thomas, M & Wyman, MD 2005, 'Dynamo-free plasma in the reversed-field pinch: Advances in understanding the reversed-field pinch improved confinement mode', Physics of Plasmas, vol. 12, no. 5, 056118, pp. 1-7. https://doi.org/10.1063/1.1883666

TY - JOUR

T1 - Dynamo-free plasma in the reversed-field pinch

T2 - Advances in understanding the reversed-field pinch improved confinement mode

AU - Anderson, J. K.

AU - Adney, J.

AU - Almagri, A.

AU - Blair, A.

AU - Brower, D. L.

AU - Cengher, M.

AU - Chapman, B. E.

AU - Choi, S.

AU - Craig, D.

AU - Demers, D. R.

AU - Hartog, D. J.Den

AU - Deng, B.

AU - Ding, W. X.

AU - Ebrahimi, F.

AU - Ennis, D.

AU - Fiksel, G.

AU - Forest, C. B.

AU - Franz, P.

AU - Goetz, J.

AU - Harvey, R. W.

AU - Holly, D.

AU - Hudson, B.

AU - Kaufman, M.

AU - Lovell, T.

AU - Marrelli, L.

AU - Martin, P.

AU - McCollam, K.

AU - Mirnov, V. V.

AU - Nonn, P.

AU - O'Connell, R.

AU - Oliva, S.

AU - Piovesan, P.

AU - Prager, S. C.

AU - Predebon, I.

AU - Sarff, J. S.

AU - Spizzo, G.

AU - Svidzinski, V.

AU - Thomas, M.

AU - Wyman, M. D.

N1 - Funding Information: This work was supported by the U.S. Department of Energy and National Science Foundation.

PY - 2005/5

Y1 - 2005/5

N2 - Generation and sustainment of the reversed field pinch (RFP) magnetic configuration normally relies on dynamo activity. The externally applied electric field tends to drive the equilibrium away from the relaxed, minimum energy state which is roughly described by a flat normalized parallel current density profile and is at marginal stability to tearing modes. Correlated fluctuations of magnetic field and velocity create a dynamo electric field which broadens the parallel current density profile, supplying the necessary edge current drive. These pervasive magnetic fluctuations are also responsible for destruction of flux surfaces, relegating the standard RFP to a stochastic-magnetic transport-limited device. Application of a tailored electric field profile (which matches the relaxed current density profile) allows sustainment of the RFP configuration without dynamo-driven edge current. The method used to ascertain that a dynamo-free RFP plasma has been created is reported here in detail. Several confinement improvements during the accompanying periods of low magnetic fluctuations are observed. Namely, the magnetic fluctuation level is reduced to the point where stochastic-magnetic transport is no longer the dominant process in the core and nested flux surfaces are restored in the core of the dynamo-free RFP.

AB - Generation and sustainment of the reversed field pinch (RFP) magnetic configuration normally relies on dynamo activity. The externally applied electric field tends to drive the equilibrium away from the relaxed, minimum energy state which is roughly described by a flat normalized parallel current density profile and is at marginal stability to tearing modes. Correlated fluctuations of magnetic field and velocity create a dynamo electric field which broadens the parallel current density profile, supplying the necessary edge current drive. These pervasive magnetic fluctuations are also responsible for destruction of flux surfaces, relegating the standard RFP to a stochastic-magnetic transport-limited device. Application of a tailored electric field profile (which matches the relaxed current density profile) allows sustainment of the RFP configuration without dynamo-driven edge current. The method used to ascertain that a dynamo-free RFP plasma has been created is reported here in detail. Several confinement improvements during the accompanying periods of low magnetic fluctuations are observed. Namely, the magnetic fluctuation level is reduced to the point where stochastic-magnetic transport is no longer the dominant process in the core and nested flux surfaces are restored in the core of the dynamo-free RFP.

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DO - 10.1063/1.1883666

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JO - Physics of Plasmas

JF - Physics of Plasmas

IS - 5

M1 - 056118

ER -

Dynamo-free plasma in the reversed-field pinch: Advances in understanding the reversed-field pinch improved confinement mode

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