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Title: Avalanches driven by pressure gradients in a magnetized plasma

Abstract

The results are presented for a basic heat transport experiment involving an off-axis heat source in which avalanche events occur. The configuration consists of a long, hollow, cylindrical region of elevated electron temperature embedded in a colder plasma, and far from the device walls [Van Compernolle et al. Phys. Rev. E 91, 031102(R) (2015)]. The avalanche events are identified as sudden rearrangements of the pressure profile following the growth of fluctuations from ambient noise. The intermittent collapses of the plasma pressure profile are associated with unstable drift-Alfvén waves and exhibit both radial and poloidal dynamics. After each collapse, the plasma enters a quiescent phase in which the pressure profile slowly recovers and steepens until a threshold is exceeded, and the process repeats. The use of reference probes as time markers allows for the visualization of the 2D spatio-temporal evolution of the avalanche events. Avalanches are observed only for a limited combination of heating powers and magnetic fields. At higher heating powers, the system transits from the avalanche regime into a regime dominated by sustained drift-Alfvén wave activity. Here, this manuscript focuses on new results that illustrate the individual contributions to the avalanche process from density and temperature gradients in themore » presence of zero-order, sheared flows.« less

Authors:
ORCiD logo [1];  [1]
  1. Univ. of California, Los Angeles, CA (United States). Dept. of Physics
Publication Date:
Research Org.:
Univ. of California, Los Angeles, CA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1524581
Alternate Identifier(s):
OSTI ID: 1407835
Grant/Contract Number:  
FC02-07ER54918
Resource Type:
Accepted Manuscript
Journal Name:
Physics of Plasmas
Additional Journal Information:
Journal Volume: 24; Journal Issue: 11; Journal ID: ISSN 1070-664X
Publisher:
American Institute of Physics (AIP)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY

Citation Formats

Van Compernolle, B., and Morales, G. J. Avalanches driven by pressure gradients in a magnetized plasma. United States: N. p., 2017. Web. doi:10.1063/1.5001321.
Van Compernolle, B., & Morales, G. J. Avalanches driven by pressure gradients in a magnetized plasma. United States. doi:10.1063/1.5001321.
Van Compernolle, B., and Morales, G. J. Tue . "Avalanches driven by pressure gradients in a magnetized plasma". United States. doi:10.1063/1.5001321. https://www.osti.gov/servlets/purl/1524581.
@article{osti_1524581,
title = {Avalanches driven by pressure gradients in a magnetized plasma},
author = {Van Compernolle, B. and Morales, G. J.},
abstractNote = {The results are presented for a basic heat transport experiment involving an off-axis heat source in which avalanche events occur. The configuration consists of a long, hollow, cylindrical region of elevated electron temperature embedded in a colder plasma, and far from the device walls [Van Compernolle et al. Phys. Rev. E 91, 031102(R) (2015)]. The avalanche events are identified as sudden rearrangements of the pressure profile following the growth of fluctuations from ambient noise. The intermittent collapses of the plasma pressure profile are associated with unstable drift-Alfvén waves and exhibit both radial and poloidal dynamics. After each collapse, the plasma enters a quiescent phase in which the pressure profile slowly recovers and steepens until a threshold is exceeded, and the process repeats. The use of reference probes as time markers allows for the visualization of the 2D spatio-temporal evolution of the avalanche events. Avalanches are observed only for a limited combination of heating powers and magnetic fields. At higher heating powers, the system transits from the avalanche regime into a regime dominated by sustained drift-Alfvén wave activity. Here, this manuscript focuses on new results that illustrate the individual contributions to the avalanche process from density and temperature gradients in the presence of zero-order, sheared flows.},
doi = {10.1063/1.5001321},
journal = {Physics of Plasmas},
number = 11,
volume = 24,
place = {United States},
year = {2017},
month = {11}
}

Journal Article:
Free Publicly Available Full Text
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Cited by: 2 works
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Figures / Tables:

FIG. 1 FIG. 1: (a) Schematic of the experimental setup, not to scale. A ring-shaped LaB6 cathode injects low-energy electrons into a large, cold, magnetized plasma; it acts as an ideal, hollow, cylindrical heat source. (b) Front end of the cathode assembly. (c) Contour of ion saturation current measured on a planemore » across the magnetic field.« less

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Works referenced in this record:

Multiple Avalanches across the Metal-Insulator Transition of Vanadium Oxide Nanoscaled Junctions
journal, July 2008


Observation of Simultaneous Axial and Transverse Classical Heat Transport in a Magnetized Plasma
journal, October 1998


Theory of mean poloidal flow generation by turbulence
journal, July 1991

  • Diamond, P. H.; Kim, Y. ‐B.
  • Physics of Fluids B: Plasma Physics, Vol. 3, Issue 7
  • DOI: 10.1063/1.859681

Spectral statistics of global avalanches along granular piles
journal, November 1997


Rotation shear induced fluctuation decorrelation in a toroidal plasma
journal, September 1994


A review of ELMs in divertor tokamaks
journal, February 1997


Edge localized modes (ELMs)
journal, February 1996


A novel angular motion vacuum feedthrough
journal, August 2001

  • Leneman, D.; Gekelman, W.
  • Review of Scientific Instruments, Vol. 72, Issue 8
  • DOI: 10.1063/1.1374588

Solar flares and avalanches in driven dissipative systems
journal, July 1993

  • Lu, Edward T.; Hamilton, Russell J.; McTiernan, J. M.
  • The Astrophysical Journal, Vol. 412
  • DOI: 10.1086/172966

Influence of sheared poloidal rotation on edge turbulence
journal, January 1990

  • Biglari, H.; Diamond, P. H.; Terry, P. W.
  • Physics of Fluids B: Plasma Physics, Vol. 2, Issue 1
  • DOI: 10.1063/1.859529

Spontaneous Thermal Waves in a Magnetized Plasma
journal, July 2008


Turbulence and transport suppression scaling with flow shear on the Large Plasma Device
journal, May 2013

  • Schaffner, D. A.; Carter, T. A.; Rossi, G. D.
  • Physics of Plasmas, Vol. 20, Issue 5
  • DOI: 10.1063/1.4804637

Wave and transport studies utilizing dense plasma filaments generated with a lanthanum hexaboride cathode
journal, December 2011

  • Van Compernolle, B.; Gekelman, W.; Pribyl, P.
  • Physics of Plasmas, Vol. 18, Issue 12
  • DOI: 10.1063/1.3671909

Drift-Alfvén fluctuations associated with a narrow pressure striation
journal, January 2000

  • Peñano, J. R.; Morales, G. J.; Maggs, J. E.
  • Physics of Plasmas, Vol. 7, Issue 1
  • DOI: 10.1063/1.873789

Snow avalanche formation
journal, January 2003


Trapping phenomena in avalanche photodiodes on nanosecond scale
journal, December 1991

  • Cova, S.; Lacaita, A.; Ripamonti, G.
  • IEEE Electron Device Letters, Vol. 12, Issue 12
  • DOI: 10.1109/55.116955

Exponential frequency spectrum and Lorentzian pulses in magnetized plasmas
journal, December 2008

  • Pace, D. C.; Shi, M.; Maggs, J. E.
  • Physics of Plasmas, Vol. 15, Issue 12
  • DOI: 10.1063/1.3023155

Transport properties of a hollow pressure filament in a magnetized plasma
journal, September 2016

  • Poulos, M. J.; Morales, G. J.
  • Physics of Plasmas, Vol. 23, Issue 9
  • DOI: 10.1063/1.4962574

Experimental study of fluctuations excited by a narrow temperature filament in a magnetized plasma
journal, May 2000

  • Burke, A. T.; Maggs, J. E.; Morales, G. J.
  • Physics of Plasmas, Vol. 7, Issue 5
  • DOI: 10.1063/1.873957

The upgraded Large Plasma Device, a machine for studying frontier basic plasma physics
journal, February 2016

  • Gekelman, W.; Pribyl, P.; Lucky, Z.
  • Review of Scientific Instruments, Vol. 87, Issue 2
  • DOI: 10.1063/1.4941079

    Works referencing / citing this record:

    Detection of an electron beam in a high density plasma via an electrostatic probe
    journal, May 2018

    • Majeski, Stephen; Yoo, Jongsoo; Zweben, Stewart
    • Plasma Physics and Controlled Fusion, Vol. 60, Issue 7
    • DOI: 10.1088/1361-6587/aabd0e