# Helical axis stellarator equilibrium model

## Abstract

An asymptotic model is developed to study MHD equilibria in toroidal systems with a helical magnetic axis. Using a characteristic coordinate system based on the vacuum field lines, the equilibrium problem is reduced to a two-dimensional generalized partial differential equation of the Grad-Shafranov type. A stellarator-expansion free-boundary equilibrium code is modified to solve the helical-axis equations. The expansion model is used to predict the equilibrium properties of Asperators NP-3 and NP-4. Numerically determined flux surfaces, magnetic well, transform, and shear are presented. The equilibria show a toroidal Shafranov shift.

- Authors:

- Publication Date:

- Research Org.:
- Princeton Univ., NJ (USA). Plasma Physics Lab.

- OSTI Identifier:
- 6117137

- Report Number(s):
- PPPL-2195

ON: DE85008716

- DOE Contract Number:
- AC02-76CH03073

- Resource Type:
- Technical Report

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; STELLARATORS; MAGNETIC FIELD CONFIGURATIONS; EQUILIBRIUM PLASMA; HELICAL CONFIGURATION; MAGNETIC FLUX; MATHEMATICAL MODELS; ROTATIONAL TRANSFORM; SHEAR; CLOSED PLASMA DEVICES; CONFIGURATION; PLASMA; THERMONUCLEAR DEVICES; 700202* - Fusion Power Plant Technology- Magnet Coils & Fields

### Citation Formats

```
Koniges, A E, and Johnson, J L.
```*Helical axis stellarator equilibrium model*. United States: N. p., 1985.
Web. doi:10.2172/6117137.

```
Koniges, A E, & Johnson, J L.
```*Helical axis stellarator equilibrium model*. United States. https://doi.org/10.2172/6117137

```
Koniges, A E, and Johnson, J L. Fri .
"Helical axis stellarator equilibrium model". United States. https://doi.org/10.2172/6117137. https://www.osti.gov/servlets/purl/6117137.
```

```
@article{osti_6117137,
```

title = {Helical axis stellarator equilibrium model},

author = {Koniges, A E and Johnson, J L},

abstractNote = {An asymptotic model is developed to study MHD equilibria in toroidal systems with a helical magnetic axis. Using a characteristic coordinate system based on the vacuum field lines, the equilibrium problem is reduced to a two-dimensional generalized partial differential equation of the Grad-Shafranov type. A stellarator-expansion free-boundary equilibrium code is modified to solve the helical-axis equations. The expansion model is used to predict the equilibrium properties of Asperators NP-3 and NP-4. Numerically determined flux surfaces, magnetic well, transform, and shear are presented. The equilibria show a toroidal Shafranov shift.},

doi = {10.2172/6117137},

url = {https://www.osti.gov/biblio/6117137},
journal = {},

number = ,

volume = ,

place = {United States},

year = {1985},

month = {2}

}

Save to My Library

You must Sign In or Create an Account in order to save documents to your library.