ANS is committed to advancing, fostering, and promoting the development and application of nuclear sciences and technologies to benefit society.
Explore the many uses for nuclear science and its impact on energy, the environment, healthcare, food, and more.
Explore membership for yourself or for your organization.
Conference Spotlight
2026 ANS Annual Conference
May 31–June 3, 2026
Denver, CO|Sheraton Denver
Latest Magazine Issues
Feb 2026
Jul 2025
Latest Journal Issues
Nuclear Science and Engineering
March 2026
Nuclear Technology
February 2026
Fusion Science and Technology
January 2026
Latest News
Fusion energy: Progress, partnerships, and the path to deployment
Over the past decade, fusion energy has moved decisively from scientific aspiration toward a credible pathway to a new energy technology. Thanks to long-term federal support, we have significantly advanced our fundamental understanding of plasma physics—the behavior of the superheated gases at the heart of fusion devices. This knowledge will enable the creation and control of fusion fuel under conditions required for future power plants. Our progress is exemplified by breakthroughs at the National Ignition Facility and the Joint European Torus.
W. M. Stacey, Jr.
Fusion Science and Technology | Volume 23 | Number 2 | March 1993 | Pages 157-166
Technical Paper | Plasma Engineering | doi.org/10.13182/FST93-A30145
Articles are hosted by Taylor and Francis Online.
A new “rotational” energy flux is derived for highly collisional impurity ions in tokamaks with strong unbalanced neutral beam injection (NBI). The derivation is based on a consistent ordering of kinetic theory. The rotational flux, which is of a collisional origin and vanishes when the rotation vanishes, is ∼ε2δ−1 times larger than the conventional neoclassical energy flux. This rotational energy flux and a previously derived momentum flux of a similar nature reproduce the experimentally observed relation between momentum and ion energy transport, τφ/τi ∼ O(1), χφ/χi ∼ O(1). The magnitude of χi resulting from this rotational energy flux is the same as is observed in many tokamaks with strong unbalanced NBI. This suggests the control of energy confinement via the control of impurity content in strongly rotating tokamak plasmas.
