| Full text | |
| Author(s): |
Pereira, F. A. C.
[1, 2]
;
Toufen, D. L.
[3]
;
Guimaraes-Filho, Z. O.
[2]
;
Caldas, I. L.
[2]
;
Viana, R. L.
[1]
;
Gentle, K. W.
[4, 5]
Total Authors: 6
|
| Affiliation: | [1] Univ Fed Parana, Dept Phys, BR-81531990 Curitiba, Parana - Brazil
[2] Univ Sao Paulo, Inst Phys, BR-05315970 Sao Paulo, SP - Brazil
[3] Fed Inst Educ Sci & Technol Sao Paulo, BR-07115000 Guarulhos, SP - Brazil
[4] Univ Texas Austin, Dept Phys, Austin, TX 78712 - USA
[5] Univ Texas Austin, Inst Fus Studies, Austin, TX 78712 - USA
Total Affiliations: 5
|
| Document type: | Journal article |
| Source: | Physics of Plasmas; v. 28, n. 3 MAR 2021. |
| Web of Science Citations: | 0 |
| Abstract | |
The turbulence of magnetically confined plasmas usually presents high-density pulses with short duration known as bursts. In the Texas Helimak, it is possible to suppress bursts in a broader region by applying a negative electrostatic bias. However, an almost unchanged burst rate persists in a region far from the location where bias is applied. We investigate the turbulence transition that occurs from the burst suppressed region to the burst dominated region by analyzing data from Langmuir probes in the whole radial extension of the machine. We find that such turbulence transition can be understood as an alternation of two different turbulent regimes, with the probability of being in each regime depending on the radial position. One regime, named as burst-free regime, consists of only Gaussian fluctuations and the other, named as bursty turbulent regime, is a train of pulses with double exponential temporal profiles, exponential amplitude distribution, and random occurring instants. This succession between burst-free and bursty turbulent regimes influences the equilibrium parameters. (AU) | |
| FAPESP's process: | 18/03211-6 - Non linear dynamics |
| Grantee: | Iberê Luiz Caldas |
| Support Opportunities: | Research Projects - Thematic Grants |
| FAPESP's process: | 15/50122-0 - Dynamic phenomena in complex networks: basics and applications |
| Grantee: | Elbert Einstein Nehrer Macau |
| Support Opportunities: | Research Projects - Thematic Grants |
| FAPESP's process: | 17/23128-3 - Turbulence and transport models for the Texas Helimak |
| Grantee: | Felipe Augusto Cardoso Pereira |
| Support Opportunities: | Scholarships abroad - Research Internship - Post-doctor |