Momentum transport studies from multi-machine comparisons (Articolo in rivista)

Type
Label
  • Momentum transport studies from multi-machine comparisons (Articolo in rivista) (literal)
Anno
  • 2012-01-01T00:00:00+01:00 (literal)
Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#doi
  • 10.1088/0029-5515/52/12/123005 (literal)
Alternative label
  • Yoshida, M [ 1 ] ; Kaye, S [ 2 ] ; Rice, J [ 3 ] ; Solomon, W [ 2 ] ; Tala, T [ 4 ] ; Bell, RE [ 2 ] ; Burrell, KH [ 5 ] ; Ferreira, J [ 6 ] ; Kamada, Y [ 1 ] ; McDonald, D [ 7,8 ] ; Mantica, P [ 9 ] ; Podpaly, Y [ 3 ] ; Reinke, ML [ 3 ] ; Sakamoto, Y [ 1 ] ; Salmi, A [ 4 ]; and ITPA Transport & Confinement Topical Group (2012)
    Momentum transport studies from multi-machine comparisons
    in Nuclear fusion (Online)
    (literal)
Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#autori
  • Yoshida, M [ 1 ] ; Kaye, S [ 2 ] ; Rice, J [ 3 ] ; Solomon, W [ 2 ] ; Tala, T [ 4 ] ; Bell, RE [ 2 ] ; Burrell, KH [ 5 ] ; Ferreira, J [ 6 ] ; Kamada, Y [ 1 ] ; McDonald, D [ 7,8 ] ; Mantica, P [ 9 ] ; Podpaly, Y [ 3 ] ; Reinke, ML [ 3 ] ; Sakamoto, Y [ 1 ] ; Salmi, A [ 4 ]; and ITPA Transport & Confinement Topical Group (literal)
Pagina inizio
  • 123005 (literal)
Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#url
  • http://iopscience.iop.org/0029-5515/52/12/123005/ (literal)
Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#numeroVolume
  • 52 (literal)
Rivista
Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#numeroFascicolo
  • 12 (literal)
Note
  • ISI Web of Science (WOS) (literal)
Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#affiliazioni
  • [ 1 ] Japan Atom Energy Agcy, Naka, Ibaraki 3110193, Japan [ 2 ] Princeton Univ, Princeton Plasma Phys Lab, Princeton, NJ 08543 USA [ 3 ] MIT, Plasma Sci & Fus Ctr, Cambridge, MA 02139 USA [ 4 ] Assoc EURATOM Tekes, FIN-02044 Espoo, Finland [ 5 ] Gen Atom Co, San Diego, CA 92186 USA [ 6 ] Univ Tecn Lisboa, Assoc EURATOM IST, Inst Plasmas & Fusao Nucl, Inst Super Tecn, P-1049001 Lisbon, Portugal [ 7 ] Culham Ctr Fus Energy, Abingdon, Oxon, England [ 8 ] EFDA CSU Garching, Munich, Germany [ 9 ] Istituto di Fisica del Plasma CNR EURATOM, I-20125 Milan, Italy (literal)
Titolo
  • Momentum transport studies from multi-machine comparisons (literal)
Abstract
  • A database of toroidal momentum transport on five tokamaks, Alcator C-Mod, DIII-D, JET, NSTX and JT-60U, has been constructed under a wide range of conditions in order to understand the characteristics of toroidal momentum transport coefficients, namely the toroidal momentum diffusivity (chi(phi)) and the pinch velocity (V-pinch). Through an inter-machine comparison, the similarities and differences in the properties of chi(phi) and V-pinch among the machines have been clarified. Parametric dependences of these momentum transport coefficients have been investigated over a wide range of plasma parameters taking advantage of the different operation regimes in machines. The approach offers insights into the parametric dependences as follows. The toroidal momentum diffusivity (chi(phi)) generally increases with increasing heat diffusivity (chi(i)). The correlation is observed over a wide range of chi(phi), covering roughly two orders of magnitude, and within each of the machines over the whole radius. Through the inter-machine comparison, it is found that chi(phi) becomes larger in the outer region of the plasma. Also observed is a general trend for V-pinch in tokamaks; the inward pinch velocity (-V-pinch) increases with increasing chi(phi). The results that are commonly observed in machines will support a toroidal rotation prediction in future devices. On the other hand, differences among machines have been observed. The toroidal momentum diffusivity, chi(phi), is larger than or equal to chi(i) in JET and JT-60U; on the other hand, chi(phi) is smaller than or equal to chi(i) in NSTX, DIII-D and Alcator C-Mod. In DIII-D, the ratio -RVpinch/chi(phi) at r/a = 0.5-0.6 is about 2, which is small compared with that in other tokamaks (-RVpinch/chi(phi) approximate to 5). Based on these different observations, parametric dependences of chi(phi)/chi(i), RVpinch/chi(phi) and chi(phi) have been investigated in H-mode plasmas. Across the dataset from all machines, the ratio chi(phi)/chi(i) tends to be larger in low nu(e)* at fixed T-e/T-i and rho(pol)*. An increase in chi(phi) is observed with decreasing n(e) and/or increasing T-e. The pinch number (-RVpinch/chi(phi)) is observed to increase with increasing R/L-ne at both q(95) = 5.5-7.2 and q(95) = 3.7-4.5. Here nu(e)*, nu(pol)*, T-e, T-i, R/L-ne and q(95) are, respectively, the normalized effective electron collision frequency, the normalized ion poloidal Larmor radius, the electron and ion temperatures, the inverse ratio of density scale length, L-ne, to the major radius, R, and the safety factor at the 95% flux surface. (literal)
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