Nonlinear gyrokinetic simulations of the I-mode high confinement regime and comparisons with experimenta)

For the first time, nonlinear gyrokinetic simulations of I-mode plasmas are performed and compared with experiment. I-mode is a high confinement regime, featuring energy confinement similar to H-mode, but without enhanced particle and impurity particle confinement [D. G. Whyte et al., Nucl. Fusion 50, 105005 (2010)]. As a consequence of the separation between heat and particle transport, I-mode exhibits several favorable characteristics compared to H-mode. The nonlinear gyrokinetic code GYRO [J. Candy and R. E. Waltz, J Comput. Phys. 186, 545 (2003)] is used to explore the effects of E × B shear and profile stiffness in I-mode and compare with L-mode. The nonlinear GYRO simulations show that I-mode core ion temperature and electron temperature profiles are more stiff than L-mode core plasmas. Scans of the input E × B shear in GYRO simulations show that E × B shearing of turbulence is a stronger effect in the core of I-mode than L-mode. The nonlinear simulations match the observed reductions in long wavelength density fluctuation levels across the L-I transition but underestimate the reduction of long wavelength electron temperature fluctuation levels. The comparisons between experiment and gyrokinetic simulations for I-mode suggest that increased E × B shearing of turbulence combined with increased profile stiffness are responsible for the reductions in core turbulence observed in the experiment, and that I-mode resembles H-mode plasmas more than L-mode plasmas with regards to marginal stability and temperature profile stiffness.United States. Department of Energy (Contract No. DE-FC02-99ER54512-CMOD)United States. Department of Energy. Office of Science (Contract No. DE-AC02- 05CH11231

Editorial: Who Is Afraid to Give Freedom of Speech to Marketing Folks?

Despite the invaluable contribution of marketing folks (e.g., making markets work), they fail to enjoy the same freedom of speech as others. This fact is particularly egregious because unlike other groups that can use threats, force, or coercion, marketing folks rely only on speech. Although the U.S. Constitution never mentions commercial speech, the courts invented the concept to censor marketing folks. The cloudy rational was that consumers need special protection from marketing folks (e.g., advertising). Naturally, censorship leads to abuse. Powerful incumbents use censorship covertly against new entrants. Politicians use censorship surreptitiously to promote their own political goals. If consumers need protection, it is certainly from the misleading statements of those with freedom of speech—politicians, attorneys, the news media, and the censors.freedom of speech, commercial speech, censorship, advertising, marketing, regulation, branding