# Bulletin of the American Physical Society

# 49th Annual Meeting of the Division of Plasma Physics

## Volume 52, Number 11

## Monday–Friday, November 12–16, 2007; Orlando, Florida

### Session GP8: Poster Session III: Turbulence, Transport, and NL Processes; Fast Ignition and Laser-Plasma Interactions; Divertors, Edge Physics and Fueling; MHD Theory, Heating and Current Drive; Simulation: MHD; Optimal Helicon Source Performance

Tuesday, November 13, 2007

Rosen Centre Hotel
Room: Grand Ballroom, 9:30am - 12:30pm

Abstract ID: BAPS.2007.DPP.GP8.106

### Abstract: GP8.00106 : An Optimal Magnetic Coordinate system for High-Beta ST configurations*

Preview Abstract Abstract

#### Author:

Janardhan Manickam

(Princeton Plasma Physics Laboratory)

In the study of magnetohydrodynamics of magnetically confined systems, it is well known that both analysis and computation are facilitated by an appropriate coordinate system. Specifically, a magnetic coordinate system,$(\Psi,\theta,\zeta)$,where $\Psi$ is a flux label, $\theta$ a poloidal angle and $\zeta$ a generalized toroidal angle, such that magnetic field lines are straight in $(\theta,\zeta)$ space. The generalized toroidal angle, $\zeta$, can be related to the Cartesian angle $\phi$, by introducing a periodic function $\delta(\Psi,\theta)$. This function depends on the choice of Jacobian, and is identically zero when the Jacobian is proportional to $x^2$. This coordinate is commonly referred to as PEST coordinates. A more general approach to straight field line coordinates is obtained when the Jacobian is defined as $J = X^i/\alpha(\Psi) |\nabla\dot\Psi|^j$. Commonly used coordinate systems are: PEST, with i=2 , j=0; Equal Arcs, with i=j=1; and Hamada with i=j=0. Each of these coordinates has its own merits, but for high beta spherical tori, we identify a new coordinate system, i=0, j=1, which is optimal to this regime. We present results comparing the different coordinate systems in different parameter regimes.

*This work was supported by DoE Contract No. DE-AC02-76-CHO-3073.

To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2007.DPP.GP8.106

## Follow Us |
## Engage
Become an APS Member |
## My APS
Renew Membership |
## Information for |
## About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |

© 2018 American Physical Society
| All rights reserved | Terms of Use
| Contact Us

**Headquarters**
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200

**Editorial Office**
1 Research Road, Ridge, NY 11961-2701
(631) 591-4000

**Office of Public Affairs**
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700