排序方式: 共有25条查询结果,搜索用时 62 毫秒
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Lazarus EA Navratil GA Greenfield CM Strait EJ Austin ME Burrell KH Casper TA Baker DR DeBoo JC Doyle EJ Durst R Ferron JR Forest CB Gohil P Groebner RJ Heidbrink WW Hong R Houlberg WA Howald AW Hsieh C Hyatt AW Jackson GL Kim J Lao LL Lasnier CJ Leonard AW Lohr J La Haye RJ Maingi R Miller RL Murakami M Osborne TH Perkins LJ Petty CC Rettig CL Rhodes TL Rice BW Sabbagh SA Schissel DP Scoville JT Snider RT Staebler GM Stallard BW Stambaugh RD St John HE Stockdale RE Taylor PL Thomas DM 《Physical review letters》1996,77(13):2714-2717
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Reimerdes H Berkery JW Lanctot MJ Garofalo AM Hanson JM In Y Okabayashi M Sabbagh SA Strait EJ 《Physical review letters》2011,106(21):215002
Active measurements of the plasma stability in tokamak plasmas reveal the importance of kinetic resonances for resistive wall mode stability. The rotation dependence of the magnetic plasma response to externally applied quasistatic n=1 magnetic fields clearly shows the signatures of an interaction between the resistive wall mode and the precession and bounce motions of trapped thermal ions, as predicted by a perturbative model of plasma stability including kinetic effects. The identification of the stabilization mechanism is an essential step towards quantitative predictions for the prospects of "passive" resistive wall mode stabilization, i.e., without the use of an "active" feedback system, in fusion-alpha heated plasmas. 相似文献
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Nazikian R Berk HL Budny RV Burrell KH Doyle EJ Fonck RJ Gorelenkov NN Holcomb C Kramer GJ Jayakumar RJ La Haye RJ McKee GR Makowski MA Peebles WA Rhodes TL Solomon WM Strait EJ Vanzeeland MA Zeng L 《Physical review letters》2006,96(10):105006
Evidence is presented for a multitude of discrete frequency Alfvén waves in the core of magnetically confined high-temperature fusion plasmas. Multiple diagnostic instruments confirm wave excitation over a wide spatial range from the device size at the longest wavelengths down to the thermal ion Larmor radius. At the shortest scales, the poloidal wavelengths are comparable to the scale length of electrostatic drift wave turbulence. Theoretical analysis confirms a dominant interaction of the modes with particles in the thermal ion distribution traveling well below the Alfvén velocity. 相似文献
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Nazikian R Fu GY Austin ME Berk HL Budny RV Gorelenkov NN Heidbrink WW Holcomb CT Kramer GJ McKee GR Makowski MA Solomon WM Shafer M Strait EJ Zeeland MA 《Physical review letters》2008,101(18):185001
Intense axisymmetric oscillations driven by suprathermal ions injected in the direction counter to the toroidal plasma current are observed in the DIII-D tokamak. The modes appear at nearly half the ideal geodesic acoustic mode frequency, in plasmas with comparable electron and ion temperatures and elevated magnetic safety factor (q_{min}>or=2). Strong bursting and frequency chirping are observed, concomitant with large (10%-15%) drops in the neutron emission. Large electron density fluctuations (n[over ]_{e}/n_{e} approximately 1.5%) are observed with no detectable electron temperature fluctuations, confirming a dominant compressional contribution to the pressure perturbation as predicted by kinetic theory. The observed mode frequency is consistent with a recent theoretical prediction for the energetic-particle-driven geodesic acoustic mode. 相似文献
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The aim of this report is to demonstrate that the combination bands of NH2 are useful to compare the association interactions of the NH2 group of primary aliphatic amines with the recognized weak proton donor solvents, chloroform and isopropyl alcohol for example and with the weaker π-electron donors benzene and pyridine, for example. Examples of families of isosbestic curves characteristic of typical equilibrium reactions of an amine with the complexing solvents are presented including the proton donor-acceptor system, 4-phenylbutylamine with benzene. 相似文献
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Reimerdes H Chu MS Garofalo AM Jackson GL La Haye RJ Navratil GA Okabayashi M Scoville JT Strait EJ 《Physical review letters》2004,93(13):135002
The stability of the resistive-wall mode (RWM) in DIII-D plasmas above the conventional pressure limit, where toroidal plasma rotation in the order of a few percent of the Alfve n velocity is sufficient to stabilize the n=1 RWM, has been probed using the technique of active MHD spectroscopy at frequencies of a few Hertz. The measured frequency spectrum of the plasma response to externally applied rotating resonant magnetic fields is well described by a single-mode approach and provides an absolute measurement of the damping rate and the natural mode rotation frequency of the stable RWM. 相似文献
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Garofalo AM Strait EJ Johnson LC La Haye RJ Lazarus EA Navratil GA Okabayashi M Scoville JT Taylor TS Turnbull AD 《Physical review letters》2002,89(23):235001
Values of the normalized plasma pressure up to twice the free-boundary stability limit predicted by ideal magnetohydrodynamic (MHD) theory have been sustained in the DIII-D tokamak. Long-wavelength modes are stabilized by the resistive wall and rapid plasma toroidal rotation. High rotation speed is maintained by minimization of nonaxisymmetric magnetic fields, overcoming a long-standing impediment [E. J. Strait, Phys. Rev. Lett. 74, 2483 (1995)]]. The ideal-MHD pressure limit calculated with an ideal wall is observed as the operational limit to the normalized plasma pressure. 相似文献