Scaling properties of turbulence driven shear flow

Journal Article · Fri Jan 15 04:00:00 EST 2010 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.3276521· OSTI ID:21344650

Yan, Z ^[1]; Tynan, G R; Holland, C; Xu, M; Muller, S H; Yu, J H ^[1]

---

1. University of California, San Diego, La Jolla, California 92093 (United States)

The characteristics and scaling properties of the turbulence driven shear flow are investigated in a cylindrical laboratory plasma device. For a given plasma pressure, the density fluctuation amplitude and radial particle flux increase with the applied magnetic field. Strong flow shear is found to coexist at high magnetic fields (>700 G) with approx10 kHz drift wave turbulence, but not at low magnetic fields (<700 G). The absolute value of the divergence of the turbulent Reynolds stress at the shear layer is shown to increase with the magnetic field as well. For a fixed magnetic field, the shear flow is found to decrease as the discharge gas pressure is increased. The density fluctuation amplitude and divergence of the turbulent Reynolds stress also decrease with the plasma pressure. For both situations the cross phase between the radial and azimuthal components of the velocity is found to be a key factor to determine variations in the turbulent Reynolds stress at different magnetic fields and discharge pressures. The results show that the generation of the shear flow is related to the development of specific frequency components of the drift wave turbulence for a variety of plasma conditions. The linear stability analysis shows that the observed variation in the turbulence and shear flow with magnetic field is also consistent with a critical gradient behavior.

• OSTI ID: 21344650
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 1 Vol. 17; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
FLUCTUATIONS
MAGNETIC FIELDS
PLASMA
PLASMA DENSITY
PLASMA PRESSURE
SCALING
SHEAR
TURBULENCE
VARIATIONS
WAVE PROPAGATION