# Presentation: 228672

## Status of Spherical Torus Research Contributing to a Bright Fusion Energy Sciences Future

- Oak Ridge National Laboratory
- @ Princeton Plasma Physics Laboratory
**For the CDX-U, HIT-II, NSTX & Pegasus Teams**
**Fusion Power Associates Annual Meeting and Symposium**
**“****Forum on the Future of Fusion”**
- November 20  22, 2003
- Washington, D.C.

**Status of Spherical Torus Research ********Contributing to a Bright Fusion Energy Sciences Future**

***Columbia U***
***Comp-X***
***General Atomics***
***INEL***
***Johns Hopkins U***
***LANL***
***LLNL***
***Lodestar***
***MIT***
***Nova Photonics***
***NYU***
***ORNL***
***PPPL***
***PSI***
***SNL***
***UC Davis***
***UC Irvine***
***UCLA***
***UCSD***
***U Maryland***
***U New Mexico***
***U Rochester***
***U Washington***
***U Wisconsin***
***Culham Sci Ctr***
***Hiroshima U***
***HIST***
***Kyushu Tokai U***
***Niigata U***
***Tsukuba U***
***U Tokyo***
***JAERI***
***Ioffe Inst***
***TRINITI***
***KBSI***
***KAIST***
***ENEA, Frascati***
***CEA, Cadarache***
***IPP, J******ü******lich***
***IPP, Garching***
***U Quebec***

- Status of ST Research

- FPA, 11/20-22/03

## Spherical Torus Research Has Made Large Progress and Some Exciting Projections

**Why Spherical Torus (ST)?**
**Major scientific goals of ST program**
**Address primary fusion science issues**
**Enable cost-effective steps to attractive fusion energy**
**Establish physics basis for Performance Extension Test**
**National and international collaboration**

- Status of ST Research

- FPA, 11/20-22/03

## ST Research Can Address Extended Parameter Space in Support of Fusion Energy Science Goal

| Plasma Science of Extended Parameter Space |  | Goal: Optimize Fusion DEMO & Development  Steps |
| --- | --- | --- |
| Stable high T, 0 & bootstrap current fraction |  | Lowered magnetic field and device costs |
| Effective wave-energetic particle-plasma interactions |  | Efficient fusion particle, neutral beam, & RF heating |
| Reduced turbulence |  | Smaller unit size for sustained fusion burn |
| Dispersed plasma fluxes |  | Survivable plasma facing components |
| Solenoid-free startup & sustainment |  | Simplified smaller design, reduced operating cost |
| Attractive sustained burning plasma properties |  | Steady state fusion power source |

- Status of ST Research

- FPA, 11/20-22/03

## Slide 4

- Status of ST Research

- FPA, 11/20-22/03

## Slide 5

- Status of ST Research

- FPA, 11/20-22/03

## Slide 6

- Status of ST Research

- FPA, 11/20-22/03

## Lower Limit of Aspect Ratio (A) Challenges and Strengthens Toroidal Plasma Understanding

**Test MHD theory**
- Strong plasma shaping & self fields (vertical elongation  3, Bp/Bt ~ 1)
- Very high T (~ 40%), N & fBootstrap
**Understand turbulence effects**
- Small plasma size relative to gyro-radius (a/i~30–50)
- Large plasma flow (MA = Vrotation/VA  0.3)
- Large flow shearing rate (ExB  106/s)
**Explore energetic particle modes**
- Supra-Alfvénic fast ions (Vfast/VA ~ 4–5)
- High dielectric constant (= pe2/ce2 ~ 50)
**Extend understanding of edge**
- Large mirror ratio in edge B field (fT  1)
- Strong field line expansion

**ST scientific goals**
**are exciting!**

**A = R/a ******** 1.1**

- Status of ST Research

- FPA, 11/20-22/03

## Slide 8

- Status of ST Research

- FPA, 11/20-22/03

## Slide 9

- Status of ST Research

- FPA, 11/20-22/03

## Slide 10

- Status of ST Research

- FPA, 11/20-22/03

## Slide 11

- Status of ST Research

- FPA, 11/20-22/03

## Slide 12

- Status of ST Research

- FPA, 11/20-22/03

## Barrier Formation and Expansion in NSTX H-Mode Has Potential to Improve Confinement Further

**Barrier Formation and Expansion in NSTX H-Mode Has Potential to Improve Confinement Further**

**Transport**
**Barrier**
**region**
**where**
******i ****~ ********i****NC**
**and**
******e**** >> ********i**

- 1.5x

- 0.5x

- 1.0x

*Columbia U, Culham, ORNL, PPPL*

**Already good**
**confinement**

- Status of ST Research

- FPA, 11/20-22/03

## Slide 14

- Status of ST Research

- FPA, 11/20-22/03

## Slide 15

- Status of ST Research

- FPA, 11/20-22/03

## Slide 16

- Status of ST Research

- FPA, 11/20-22/03

## Slide 17

- Status of ST Research

- FPA, 11/20-22/03

## Slide 18

- Status of ST Research

- FPA, 11/20-22/03

## Slide 19

- Status of ST Research

- FPA, 11/20-22/03

## Slide 20

- Status of ST Research

- FPA, 11/20-22/03

## Slide 21

- Status of ST Research

- FPA, 11/20-22/03

## Slide 22

- Status of ST Research

- FPA, 11/20-22/03

## Slide 23

- Status of ST Research

- FPA, 11/20-22/03

## Slide 24

- Status of ST Research

- FPA, 11/20-22/03

## Spherical Torus Research Is Contributing to a Bright Fusion Energy Sciences Future

**Addresses extended parameter space in support of fusion energy sciences goals**
**Contributes to broad Innovative Confinement Concept portfolio**
**Has made rapid progress in achieving ST scientific goals**
**Aims to enable cost-effective steps to attractive fusion energy**
**Aims to establish in 5 years physics basis for Performance Extension Test**
**Carries out active national and international collaborations**

- Status of ST Research

- FPA, 11/20-22/03