Abstract
Analysis of the time series obtained with the O-Mode reflectometer [Rhodes et al., 1997 Plasma Phys. Controlled Fusion 40, 493-510 (1998)] and the gas puff imaging [Cziegler et al., Phys. Plasmas 17(5), 056120 (2010)] systems on the Alcator C-Mod tokamak reveals that the turbulent edge density fluctuations are chaotic. Supporting evidence for this conclusion includes the observation of exponential power spectra (which is associated with Lorentzian-shaped pulses in the time series), the population of the corresponding Bandt-Pompe probability distributions [Bandt and Pompe, Phys. Rev. Lett. 88, 174102 (2002)], and the location of the signal on the complexity-entropy plane (C-H plane) [Rosso et al., Phys. Rev. Lett. 99, 154102 (2007)]. The classification of edge turbulence as chaotic opens the door for further work to understand the underlying process and the impact on turbulent transport.
| Original language | English |
|---|---|
| Article number | 042301 |
| Journal | Physics of Plasmas |
| Volume | 24 |
| Issue number | 4 |
| DOIs | |
| State | Published - Apr 1 2017 |
| Externally published | Yes |
Funding
Discussions with G. Morales, J. Maggs, J. Bonde, M. Martin, and S. Dorfman are gratefully acknowledged. The authors thank V. Winters for her previous work. The experiments reported in the paper were performed at the MIT Plasma and Fusion Center. This work was supported by the U.S. Department of Energy Office of Science under Agreement Nos. DE-FC02-99ER54512 and DE-FC02-07ER54918-011.