Results 191 to 200 of about 15,788,610 (233)

Sawtooth Precursor Oscillations on DIII-D

IEEE Transactions on Plasma Science, 2011
The sawtooth oscillation, observed in tokamak plasmas with a central safety factor of less than unity, is a periodic disruptive instability characterized by a slow ramping of central plasma density and temperature, followed by a fast relaxation resulting in flattening of both profiles.
Tobias, B.J., Domier, C.W., Luhmann, N.C., Boom, J.E., Classen, I.G.J., Donne, A.J. H., Yun, G., Park, H.K., Nazikian, R.M.   +8 more
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Hybrid Scenario Development in DIII-D

Fusion Science and Technology, 2005
Experiments in the DIII-D tokamak have demonstrated the ability to sustain ELMing H-mode discharges with high beta and good confinement quality under stationary conditions. These experiments have shown the ability to sustain normalized fusion performance (in terms of {beta}{sub N}H{sub 89P} /q{sub 95}{sup 2}) at or above that projected for Q{sub fus} =
Wade, M., Luce, T., Jayakumar, R., Politzer, P., Petty, C., Murakami, M., Ferron, J., Hyatt, A., Sips, A.   +8 more
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Pedestal Studies in DIII-D

Fusion Science and Technology, 2005
Studies of the H-mode pedestal in the DIII-D tokamak are presented. The global energy confinement increases as the plasma pressure on top of the pedestal increases. The best empirical description for a pedestal width parameter is {delta}{sub pe} [proportional to] ({beta}{sub pol}{sup PED}){sup 0.4}, where {delta}{sub pe} is the width of the electron ...
R. J. Groebner, T. H. Osborne, M. E. Fenstermacher, A. W. Leonard, M. A. Mahdavi, R. A. Moyer, L. W. Owen, G. D. Porter, P. B. Snyder, P. C. Stangeby, T. L. Rhodes, N. S. Wolf   +11 more
openaire   +1 more source

Disruption prediction investigations using Machine Learning tools on DIII-D and Alcator C-Mod

Plasma Physics and Controlled Fusion, 2018
Using data-driven methodology, we exploit the time series of relevant plasma parameters for a large set of disrupted and non-disrupted discharges to develop a classification algorithm for detecting disruptive phases in shots that eventually disrupt ...
Alcator C-Mod, C. Rea, R. Granetz, K. Montes, R. A. Tinguely, N. Eidietis, J. Hanson, B. Sammuli   +7 more
semanticscholar   +1 more source

DIII-D data management

Fusion Engineering and Design, 2002
Abstract The DIII-D tokamak at the DIII-D National Fusion Facility routinely acquires ∼500MB of raw data per pulse of the experiment through a centralized data management system. It is expected that in FY01 (October 2001 to September 2002), nearly 1TB of data will be acquired.
B.B. McHarg, J.R. Burruss, J. Freeman, C.T. Parker, J. Schachter, D.P. Schissel   +5 more
openaire   +1 more source

Intrinsic rotation in DIII-D

Physics of Plasmas, 2007
In the absence of any auxiliary torque input, the DIII-D plasma consists of nonzero toroidal angular momentum, in other words, it rotates. This effect is commonly observed in tokamaks, being referred to as intrinsic rotation. Measurements of intrinsic rotation profiles have been made in DIII-D [J. Luxon, Nucl.
J. S. deGrassie, J. E. Rice, K. H. Burrell, R. J. Groebner, W. M. Solomon   +4 more
openaire   +1 more source

DIII–D RESULTS AND PLANS

1991
The completion of additional radiation shielding in the spring of 1989 has allowed the DIII-D tokamak to enter a new phase of experimental operation, in which the potential of injecting deuterium beam injection into deuterium plasmas has been exploited. The benefit of the isotope effect in increased energy confinement time, and increased power delivery
Callis, R., Anderson, P., Colleraine, A., Smith, J., Petersen, P., Taylor, P.   +5 more
openaire   +1 more source

Deuterium retention of DIII-D DiMES sample

Journal of Nuclear Materials, 1999
Abstract The deuterium retention property of B4C converted graphite and isotropic graphite exposed to DIII-D deuterium plasma was examined by using a technique of thermal desorption spectroscopy. Major outgassing species were HD, D2 and CD4 in both the graphite and the B4C. In the case of the graphite, the ratios of deuterium desorbed in the forms of
Yamauchi, Y., Hirohata, Y., Hino, T., Masaki, K., Saidoh, M., Ando, T., Whyte, D., Wong, C.   +7 more
openaire   +2 more sources

Thomson scattering diagnostic upgrade on DIII-D

Review of Scientific Instruments, 2010
The DIII-D Thomson scattering system has been upgraded. A new data acquisition hardware was installed, adding the capacity for additional spatial channels and longer acquisition times for temperature and density measurements. Detector modules were replaced with faster transimpedance circuitry, increasing the signal-to-noise ratio by a factor of 2. This
D M, Ponce-Marquez, B D, Bray, T M, Deterly, C, Liu, D, Eldon   +4 more
openaire   +2 more sources

Recent DIII-D Results

Fusion Technology, 1994
This paper summarizes the recent DIII-D experimental results and the development of the relevant hardware systems. The DIII-D program focuses on divertor solutions for next generation tokamaks such as International Thermonuclear Experimental Reactor (ITER) and Tokamak Physics Experiment (TPX), and on developing configurations with enhanced confinement ...
openaire   +1 more source