Bulletin of the American Physical Society
51st Annual Meeting of the APS Division of Plasma Physics
Volume 54, Number 15
Monday–Friday, November 2–6, 2009; Atlanta, Georgia
Session BM9: Mini-Conference on Innovative Magnetic Mirror Concepts and Applications I |
Hide Abstracts |
Chair: Xianzhu Tang, Los Alamos National Laboratory Room: The Learning Center |
Monday, November 2, 2009 9:30AM - 10:00AM |
BM9.00001: Innovative Magnetic Mirror Concepts Thomas Simonen In the past two decades, while magnetic mirror research in the US was curtailed, several innovations have been proposed and many have been demonstrated in Japan and Russia in the Gamma 10 and GDT experiments. These advances have led to new scientific understanding, means of overcoming previous short comings, and reconsideration of magnetic mirror systems as a modest size material testing neutron source or as a fusion- fission hybrid system. Compared to toroidal systems, the linear geometry of mirror systems has the significant advantages of easing construction, operation and maintenance, but has a less developed data base. The recent innovations include reliance on axi-symmetric mirror coils, suppression of energetic-ion cyclotron-modes with potential confined warm plasma, and sheared ExB flow stabilization of drift waves. To enable increased electron temperature, the magnetic field expansion ratio from the mirror to the end wall is increased beyond the square root of the ion to electron mass ratio. This expansion inhibits electron thermal conduction, reduces the incident wall power flux to low levels, and isolates plasma-wall interactions far from the confined plasma. [Preview Abstract] |
Monday, November 2, 2009 10:00AM - 10:30AM |
BM9.00002: MHD-stable axisymmetric mirrors Dmitri Ryutov The traditional way of making MHD-stable mirror configurations is to use quadrupolar magnets. This approach indeed provides stability, but only at the cost of creating complex three-dimensional plasma equilibria, with a number of undesirable features like enhanced cross-field transport, lower magnetic field, and engineering complexity. Over the years, numerous ideas have been suggested for achieving the MHD stability in axisymmetric mirrors. Some of them have been successfully tested experimentally. In this paper, a brief summary of various approaches to the axisymmetric mirror stability will be made that will include: stabilization by sloshing ions, non-paraxial stabilization, the use of magnetic divertors, sheared plasma rotation, and enhanced line-tying stabilization. Wherever possible, relation to existing experiments will be made. The general conclusion is that there are ways of providing MHD stability of the reactor-relevant plasma in axisymmetric mirrors. Prepared by LLNL under Contract DE-AC52-07NA27344. [Preview Abstract] |
Monday, November 2, 2009 10:30AM - 11:00AM |
BM9.00003: Present status of the GAMMA 10 and future plan in University of Tsukuba Tsuyoshi Imai, Makoto Ichimura, Yousuke Nakashima, Masayuki Yoshikawa, Isao Katanuma, Tsuyoshi Kariya, Hitoshi Hojo, Ryutaro Minami, Yoshiaki Miyata, Yuusuke Yamaguchi, Hiroyuki Shidara The studies of the formation of ion confining potential, the central electron heating, the suppression of drift type fluctuations by the ECH and various collaborative works have been carried out in the GAMMA 10 tandem mirror device. With high power plug ECH up to $\sim $ 500 kW, the ion confining potential of more than 2 kV was achieved. The drift type low frequency fluctuations were suppressed by the potential produced with plug ECH. The best central EC heating was observed with 100{\%} X-mode excitation. The development of a gyrotron, the key tool of these ECH experiments, has been made in collaboration with NIFS (National Institute for Fusion Science), JAEA (Japan Atomic Energy Agency) and TETD (Toshiba). The plan of the new mirror program with modification of GAMMA 10 is in progress. The new program includes the physics studies of the divertor plasma and SOL plasma relevant to torus plasmas like ITER. The high heat flux experiments using the open end mirror throat and the edge physics with introduction of the divertor coil are in consideration. [Preview Abstract] |
Monday, November 2, 2009 11:00AM - 11:30AM |
BM9.00004: Potential and density fluctuation suppressions by the potential formation and the newly installing Thomson scattering system in GAMMA 10 M. Yoshikawa, Y. Miyata, M. Mizuguchi, N. Imai, H. Hojo, M. Ichimura, T. Kariya, I. Katanuma, Y. Nakashima, R. Minami, H. Shidara, Y. Yamaguchi, Y. Shima, Y. Ohno, F Yaguchi, T. Imai, K. Kawahata, I. Yamada, H. Funaba Suppression phenomena of the potential and density fluctuation were clearly observed when the confinement potentials were produced by the application of electron cyclotron heating (ECH) in the tandem mirror GAMMA 10. We study the correlation between the suppression levels of both potential and density fluctuations and the effects of formed confinement potentials. Moreover, we show that the radial anomalous transport induces the radial particle transport which is estimated by the phase difference between the potential and density fluctuations obtained by using the gold neutral beam probe. We are now planning to measure the electron temperature by using a Thomson scattering system in GAMMA 10 by the collaboration with NIFS. In recent years, the direct electron heating experiments by central cell ECH have been carried out. The highest electron temperature, about over 500 eV, was estimated by a soft x-ray measurement. We will make a crosscheck with the newly installing Thomson scattering system for more reliable data evaluation. [Preview Abstract] |
Monday, November 2, 2009 11:30AM - 12:00PM |
BM9.00005: The Maryland Centrifugal Experiment Richard Ellis, Adil Hassam The Maryland Centrifugal Experiment(MCX) produces supersonically rotating plasmas in a mirror geometry with a radial electric field produced by a coaxial core biased at high voltage. MCX has achieved high density (n$>$10**20 m-3) fully ionized plasmas rotating with velocities of $\sim $100 km/sec for times exceeding 8 ms under a wide range of conditions. Ion temperatures are 30 eV and confinement times $\sim $100 microseconds. Sonic mach numbers are 1-3 and Alfven mach numbers somewhat less than 0.5; the maximum rotational velocity may be limited by the critical ionization velocity. MCX has achieved its major goals including the demonstration of supersonic rotation, radial velocity profiles with shear sufficient for MHD stability, overall MHD stability, and centrifugal confinement in the axial direction. Upgrade plans include a larger diameter vessel, higher field magnets, and higher discharge voltages. Possible applications to larger experiments will be discussed. [Preview Abstract] |
Monday, November 2, 2009 12:00PM - 12:30PM |
BM9.00006: The GDT-based 14MeV neutron source for fission fuel systems Alexander Ivanov The gas dynamic trap (GDT) is an axisymmetric mirror device with a high mirror ratio and with a mirror to mirror length exceeding a mean free path for the ion scattering into loss cone. A version of GDT with multi-component plasma was proposed for generation of high D-T neutron flux in localized zones to serve the needs of fusion material tests [1]. Conceptual studies demonstrated that the D-T neutron flux would reach $\sim $2MW/m$^{2}$ in these zones if the device consumes 60MW. This approach can only be realized if the high beta plasma in the GDT with anisotropic fast ions is stable against MHD and kinetic instabilities. This has been already proven both theoretically and experimentally. Recently, application of the GDT neutron source as a driver for a fission --fusion hybrid and minor actinides burner was considered. This requires certain modifications to be introduced into the initial approach, since then overall efficiency of the driver becomes important. These physical and technical modifications are discussed in the paper. \\[4pt] [1] I.A.Kotelnikov,V.V.Mirnov, V.P.Nagorny, D.D.Ryutov, In: Plasma Phys. Controll. Fusion Res., \textbf{2, }IAEA, Vienna, p.309, 1985 [Preview Abstract] |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700