# Turbulent Equipartition Theory of Toroidal Momentum Pinch

## Abstract

The mode-independet part of magnetic curvature driven turbulent convective (TuroCo) pinch of the angular momentum density [Hahm et al., Phys. Plasmas 14,072302 (2007)] which was originally derived from the gyrokinetic equation, can be interpreted in terms of the turbulent equipartition (TEP) theory. It is shown that the previous results can be obtained from the local conservation of "magnetically weighted angular momentum density," nmi U|| R/B2, and its homogenization due to turbulent flows. It is also demonstrated that the magnetic curvature modification of the parallel acceleration in the nonlinear gyrokinetic equation in the laboratory frame, which was shown to be responsible for the TEP part of the TurCo pinch of angular momentum density in the previous work, is closely related to the Coriolis drift coupling to the perturbed electric field. In addition, the origin of the diffusive flux in the rotating frame is highlighted. Finally, it is illustratd that there should be a difference in scalings between the momentum pinch originated from inherently toroidal effects and that coming from other mechanisms which exist in a simpler geometry.

- Authors:

- Publication Date:

- Research Org.:
- Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)

- Sponsoring Org.:
- USDOE Office of Science (SC)

- OSTI Identifier:
- 960371

- Report Number(s):
- PPPL-4285

TRN: US0904386

- DOE Contract Number:
- DE-ACO2-76CHO3073

- Resource Type:
- Conference

- Resource Relation:
- Conference: Forty-Ninth APS Division of Plasma Physics Meeting, 12–16 November 2007, Orlando, Florida USA

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ACCELERATION; ANGULAR MOMENTUM; ELECTRIC FIELDS; GEOMETRY; MODIFICATIONS; ORIGIN; PHYSICS; PLASMA; TURBULENT FLOW; Gyrokinetic Equations; Rotating Plasmas; Transport Theory

### Citation Formats

```
T.S. Hahm, P.H. Diamond, O.D. Gurcan, and G. Rewaldt.
```*Turbulent Equipartition Theory of Toroidal Momentum Pinch*. United States: N. p., 2008.
Web.

```
T.S. Hahm, P.H. Diamond, O.D. Gurcan, and G. Rewaldt.
```*Turbulent Equipartition Theory of Toroidal Momentum Pinch*. United States.

```
T.S. Hahm, P.H. Diamond, O.D. Gurcan, and G. Rewaldt. Thu .
"Turbulent Equipartition Theory of Toroidal Momentum Pinch". United States. https://www.osti.gov/servlets/purl/960371.
```

```
@article{osti_960371,
```

title = {Turbulent Equipartition Theory of Toroidal Momentum Pinch},

author = {T.S. Hahm, P.H. Diamond, O.D. Gurcan, and G. Rewaldt},

abstractNote = {The mode-independet part of magnetic curvature driven turbulent convective (TuroCo) pinch of the angular momentum density [Hahm et al., Phys. Plasmas 14,072302 (2007)] which was originally derived from the gyrokinetic equation, can be interpreted in terms of the turbulent equipartition (TEP) theory. It is shown that the previous results can be obtained from the local conservation of "magnetically weighted angular momentum density," nmi U|| R/B2, and its homogenization due to turbulent flows. It is also demonstrated that the magnetic curvature modification of the parallel acceleration in the nonlinear gyrokinetic equation in the laboratory frame, which was shown to be responsible for the TEP part of the TurCo pinch of angular momentum density in the previous work, is closely related to the Coriolis drift coupling to the perturbed electric field. In addition, the origin of the diffusive flux in the rotating frame is highlighted. Finally, it is illustratd that there should be a difference in scalings between the momentum pinch originated from inherently toroidal effects and that coming from other mechanisms which exist in a simpler geometry.},

doi = {},

journal = {},

number = ,

volume = ,

place = {United States},

year = {2008},

month = {1}

}