Results 21 to 30 of about 4,697,162 (157)

Upward-facing lithium flash evaporator for NSTX-U [PDF]

2013 IEEE 25th Symposium on Fusion Engineering (SOFE), 2013
NSTX plasma performance has been significantly enhanced by lithium conditioning [1]. To date, the lower divertor and passive plates have been conditioned by downward facing lithium evaporators (LITER) as appropriate for lower null plasmas. The higher power operation expected from NSTX-U requires double null plasma operation in order to distribute the ...
A. L. Roquemore, D. Andruczyk, R. Majeski, D. K. Mansfield, C. H. Skinner, D. Rodgers   +5 more
openaire   +2 more sources

On the scattering correction of fast-ion D-alpha signals on NSTX-U

Review of Scientific Instruments, 2018
Analysis of fast-ion D-alpha (FIDA) data on National Spherical Torus Experiment-Upgrade (NSTX-U) shows that the cold Dα line contaminates the FIDA baseline. The scattered light is comparable to the FIDA emission. A scattering correction is required to extract the FIDA signal. Two methods that relate the scattered light contamination to the intensity of
G. Z. Hao, W. W. Heidbrink, D. Liu, L. Stagner, M. Podestà, A. Bortolon   +5 more
openaire   +4 more sources

Effect of deuterium irradiation on graphite boronized in the NSTX-U tokamak. [PDF]

Sci Rep, 2019
AbstractBoronization has been used in the National Spherical Torus-Upgrade (NSTX-U) as first wall conditioning technique. The technique decreased the oxygen impurities in the plasma and the O% on the Plasma Facing Components (PFC) as measured with an in-vacuo probe.
Bedoya F, Allain JP, Dominguez-Gutierrez FJ, Krstic PS.   +3 more
europepmc   +5 more sources

NSTX-U theory, modeling and analysis results

NSTX-U theory, modeling and analysis results
The mission of the low aspect ratio spherical tokamak NSTX-U is to advance the physics basis and technical solutions required for optimizing the configuration of next-step steady-state tokamak fusion devices. NSTX-U will ultimately operate at up to 2 MA of plasma current and 1 T toroidal field on axis for 5 s, and has available up to 15 MW of neutral ...
Domier, C., Ferraro, N., Soukhanovskii, V., Zweben, S.J., Munaretto, S., Russel, D., 1040837, 1040836, Reinke, M., 1040839, 1040838, 1040844, 1040843, 1040846, 1040845, 1040840, 1040842, 1040841, Lore, J.D., Smith, D.R., Goldston, R.J., Schuster, E., Laggner, F., Bierwage, Andreas, Duarte, V.N., Berkery, J.W., Kolemen, E., 1040829, Emdee, E.D., Gorelenkov, N.N., 1040826, Stratton, B., 1040825, 1040828, S.-H., Ku, 1040827, 1040833, 1040799, 1040832, 1040835, 1040834, 1040796, 1040798, E.-H., Kim, 1040831, 1040797, 1040830, Wirth, B., Fredrickson, E., Battaglia, D.J., Rhodes, T., Riquezes, J., Belova, E., Kaye, S.M., Banerjee, S., 1040819, Ilhan, Z., 1040818, 1040815, 1040814, 1040817, Levinton, F., 1040816, 1040822, 1040821, 1040824, 1040823, Evans, T., Chang, C.S., 1040820, Raman, R., Crocker, N., Liu, D., Ren, Y., Koel, B., Maingi, R., Stotler, D., White, A.E., 1040808, 1040807, 1040809, Menard, J.E., 1040804, 1040803, 1040806, Looby, T., Tritz, K., 1040805, Ebrahimi, F., 1040811, Luhmann, N., 1040810, 1040813, 1040812, Canal, G.P., White, R.B., Bertelli, N., Myra, J.R., Barchfeld, R., 1040800, 1040888, Gerhardt, S., 1040887, 1040802, Sabbagh, S.A., 1040801, Lestz, J.B., Vail, P., 1040884, 1040883, Diallo, A., Nichols, J.H., 1040886, 1040885, 1040880, Podesta, M., Hakim, A., 1040882, 1040881, Kubota, S., J.-K., Park, Poli, F., J. Yang, Shiraiwa, S., Scotti, F., Francisquez, M., Mandell, N., 1040869, Hammett, G., 1040877, 1040876, 1040879, 1040878, 1040873, 1040872, 1040875, Ono, M., 1040874, 1040871, 1040870, Lunsford, R., Bhattacharjee, A., Boyer, M.D., Heidbrink, W., Chen, X., 1040859, Clauser, C., 1040858, C. Liu, Wang, Z.R., Lampert, M., 1040866, 1040865, 1040868, 1040867, 1040862, 1040861, 1040864, 1040863, 1040860, Kaita, R., Guttenfelder, W., Wehner, W., Rafiq, T., Gan, K., Woods, B.J.Q., 1040848, Gray, T., LeBlanc, B.P., Ruiz Ruiz, J., 1040847, Kleiner, A., 1040849, 1040855, Jardin, S., Bell, R.E., 1040854, 1040857, 1040856, 1040851, 1040850, 1040853, 1040852, Wang, W., Maqueda, R.   +184 more
openaire   +2 more sources

Neural net modeling of equilibria in NSTX-U

Nuclear Fusion, 2022
Abstract Neural networks (NNs) offer a path towards synthesizing and interpreting data on faster timescales than traditional physics-informed computational models. In this work we develop two NNs relevant to equilibrium and shape control modeling, which are part of a suite of tools being developed for the National
J.T. Wai, M.D. Boyer, E. Kolemen
openaire   +2 more sources

Diagnostic options for radiative divertor feedback control on NSTX-U [PDF]

Review of Scientific Instruments, 2012
A radiative divertor technique is used in present tokamak experiments and planned for ITER to mitigate high heat loads on divertor plasma-facing components (PFCs) to prevent excessive material erosion and thermal damage. In NSTX, a large spherical tokamak with lithium-coated graphite PFCs and high divertor heat flux (qpeak ⩽ 15 MW/m2), radiative ...
Soukhanovskii, V A, Gerhardt, S P, Kaita, R, McLean, A G, Raman, R   +4 more
openaire   +2 more sources

Addressing the challenges of plasma-surface interactions in NSTX-U

2014 IEEE 41st International Conference on Plasma Sciences (ICOPS) held with 2014 IEEE International Conference on High-Power Particle Beams (BEAMS), 2014
The importance of conditioning plasma-facing components (PFCs) has long been recognized as a critical element in obtaining high-performance plasmas in magnetic confinement devices. Lithium coatings, for example, have been used for decades for conditioning PFCs.
R. Kaita, T. Abrams, M. Jaworski, M. Lucia, J. Nichols, C. H. Skinner, D. Stotler, J-P. Alain, F. Bedoya   +8 more
openaire   +2 more sources

Securing MDSplus for the NSTX-U Digital Coil Protection System [PDF]

2015 IEEE 26th Symposium on Fusion Engineering (SOFE), 2015
NSTX used MDSplus extensively to record data, relay information and control data acquisition hardware. For NSTX-U the same functionality is expected as well as an expansion into the realm of securely maintaining parameters for machine protection. Specifically, we designed the Digital Coil Protection System (DCPS) to use MDSplus to manage our physical ...
Tchilinguirian, Gregory J., Erickson, Keith G.   +1 more
openaire   +1 more source

A megawatt-level 28 GHz heating system for the National Spherical Torus Experiment Upgrade

EPJ Web of Conferences, 2015
The National Spherical Torus Experiment Upgrade (NSTX-U) will operate at axial toroidal fields of ≤ 1 T and plasma currents, Ip ≤ 2 MA. The development of non-inductive (NI) plasmas is a major long-term research goal for NSTX-U.
Taylor G., Ellis R.A., Fredd E., Gerhardt S. P., Greenough N., Harvey R. W., Hosea J. C., Parker R., Poli F., Raman R., Shiraiwa S., Smirnov A. P., Terry D., Wallace G., Wukitch S.   +14 more
doaj   +1 more source

Optimization of the snowflake divertor for power and particle exhaust on NSTX–U

Nuclear Materials and Energy, 2019
In this paper, simple analytical modeling and numerical simulations performed with the multi-fluid edge transport code UEDGE are used to identify optimal snowflake divertor (SFD) configurations for heat flux mitigation and sufficient cryopumping ...
P.J. Vail, O. Izacard, E. Kolemen
doaj   +1 more source