Abstract
By repeated injection of magnetic helicity (K = 2φψ) on time-scales short compared with the dissipation time (τinj << τ K ), it is possible to produce toroidal currents relevant to POP-level experiments. Here we discuss an effective injection rate, \( \dot{K}_{\text{eff}} = 2\psi_{\text{gun}} I_{\text{gun}} \dot{L} \) due to the expansion of a series of current sheets and their subsequent reconnection to form spheromaks and compression into a copper flux-conserving chamber. The benefits of repeated injection are that the usual limits to current amplification can be exceeded, and an efficient quasi-steady sustainment scenario is possible (within minimum impact on confinement). A new experiment designed to address the physics of pulsed formation and sustainment is described.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
T.K. Fowler, D.D. Hua, Prospects for spheromak fusion reactors. J. Fusion Energy 14, 181 (1995)
R.L. Hagenson, R.A. Krakowski, Fusion Technol. 8, 1606 (1985)
R.F. Bourque, J. Fusion Energy 17, 207 (1998)
S. Woodruff, “Technical Survey of Simply Connected Compact Tori (CTs).” Proc. ICC Workshop, J. Fusion Energy, 27, 134 (2008)
H. Alfvén, L. Lindberg, P. Mitlid, J. Nucl. Energy C 1, 116 (1960)
L. Lindberg, C.T. Jacobsen, Phys. Fluids S44 (1963), see also L. Lindberg, C. Jacobsen, Astrophysics J. 133 1043 (1960) and H. Alfvén, Astrophysics J. 133 1049 (1960)
W.C. Turner, G.C. Goldenbaum, E.H.A. Granneman, J.H. Hammer, C.W. Hartman, D.S. Prono, J. Taska, Phys. Fluids 26, 1965 (1983)
Y. Ono, A. Morita, M. Katsurai, M. Yamada, Phys. Fluids B 5(10), 3691 (1993)
M.R. Brown, P.M. Bellan, Phys. Rev. Lett. 64, 2144 (1990)
M. Yamada, Y. Ono, A. Hayakawa, M. Katsurai, F.W. Perkins, Phys. Rev. Lett. 65, 721 (1990)
S. Woodruff, D.N. Hill, B.W. Stallard, R. Bulmer, B. Cohen, C.T. Holcomb, E.B. Hooper, H.S. McLean, J. Moller, R.D. Wood, Phys. Rev. Lett. 90, 095001 (2003)
S. Woodruff, B.W. Stallard, H.S. McLean, E.B. Hooper, R. Bulmer, B.I. Cohen, D.N. Hill, C.T. Holcomb, J. Moller, R.D. Wood, Increasing the magnetic helicity content of a plasma by pulsing a magnetized source. Phys. Rev. Lett. 93, 205002 (2004)
S. Woodruff, B.I. Cohen, E.B. Hooper, H.S. Mclean, B.W. Stallard, D.N. Hill, C.T. Holcomb, C. Romero-Talamas, R.D. Wood, G. Cone, C.R. Sovinec, Controlled and spontaneous magnetic field generation in a gun-driven spheromak. Phys. Plasmas 12, 52502 (2005)
C.R. Sovinec, J.M. Finn, D. del-Castillo-Negrete, Phys. Plasmas 8, 475 (2001)
M.R. Brown, P.M. Bellan, Current Drive by Spheromak Injection into a Tokamak. Phys. Rev. Lett. 64(18), 2144 (1990)
P.M. Bellan, Scalings for a traveling mirror adiabatic magnetic compressor. Rev. Sci. Instrum. 53(8), 1214 (1982)
Acknowledgements
The authors would like to acknowledge useful discussions with Prof. Uri Shumlak, Dr. Harry McLean and thanks other WS, Inc team members for hard work (especially Wandee Earp). This work was performed under the auspices of the US DoE by Woodruff Scientific, Inc. under Contract No. DE-FG02-06ER84449.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Woodruff, S., Macnab, A.I.D., Ziemba, T.M. et al. Spheromak Formation and Current Sustainment Using a Repetitively Pulsed Source. J Fusion Energ 28, 229–234 (2009). https://doi.org/10.1007/s10894-008-9178-6
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10894-008-9178-6