@Article{GrenfellNOGERGBORSS:2018:HmAcRo,
               author = "Grenfell, G. G. and Nascimento, I. C. and Oliveira, D. S. and 
                         Guimar{\~a}es Filho, Z. O. and Elizondo, J. I. and Reis, A. P. 
                         and Galv{\~a}o, Ricardo Magnus Os{\'o}rio and Baquero, W. A. H. 
                         and Oliveira, A. M. and Ronchi, G. and S{\'a}, W. P. de and 
                         Severo, J. H. F.",
          affiliation = "{Universidade de S{\~a}o Paulo (USP)} and {Universidade de 
                         S{\~a}o Paulo (USP)} and {Universidade de S{\~a}o Paulo (USP)} 
                         and {Universidade de S{\~a}o Paulo (USP)} and {Universidade de 
                         S{\~a}o Paulo (USP)} and {Universidade de S{\~a}o Paulo (USP)} 
                         and {Instituto Nacional de Pesquisas Espaciais (INPE)} and 
                         {Universidade de S{\~a}o Paulo (USP)} and {Universidade de 
                         S{\~a}o Paulo (USP)} and {Universidade de S{\~a}o Paulo (USP)} 
                         and {Universidade de S{\~a}o Paulo (USP)} and {Universidade de 
                         S{\~a}o Paulo (USP)}",
                title = "H-mode access and the role of spectral shift with electrode 
                         biasing in the TCABR tokamak",
              journal = "Physics of Plasmas",
                 year = "2018",
               volume = "25",
               number = "7",
                pages = "e072301",
                month = "July",
             abstract = "The transition from the ohmic heating L-mode to the H-mode in the 
                         tokamak TCABR induced by an external electrode biasing is 
                         addressed in this work. A gradual improvement in the plasma 
                         confinement with the biasing voltage was observed as a result of 
                         the enhancement of the E B shear flow at the edge. This result was 
                         supported by the measurement of plasma parameters in different 
                         radial locations by two electrostatic probes. Radial profiles of 
                         the electron temperature (from the standard sweeping voltage 
                         technique), electron density, and radial electric field, as well 
                         as the local turbulence features, were measured. We observed that 
                         the electron density profile became steeper as the voltage on the 
                         electrode increased, while no significant change in the 
                         temperature profile was noticed. In addition, the data were 
                         compared with the spectral shift model [G. M. Staebler et al., 
                         Phys. Rev. Lett. 110, 055003 (2013)] at different bias voltages, 
                         i.e., different E B shear flows, showing a good agreement. 
                         Particularly, the gradual improvement was held: the higher the 
                         biasing voltage, the larger the radial wavenumber shift and so the 
                         turbulence suppression. Moreover, by studying the edge radial 
                         profile of the mean radial wavenumber, we show that the large 
                         shift occurs in the same position where the transport barrier is 
                         created.",
                  doi = "10.1063/1.5029561",
                  url = "http://dx.doi.org/10.1063/1.5029561",
                 issn = "1070-664X",
             language = "en",
           targetfile = "grenfell_h mode.pdf",
        urlaccessdate = "27 abr. 2024"
}