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
Jan 2026
Jul 2025
Latest Journal Issues
Nuclear Science and Engineering
February 2026
Nuclear Technology
January 2026
Fusion Science and Technology
Latest News
The spark of the Super: Teller–Ulam and the birth of the H-bomb—rivalry, credit, and legacy at 75 years
In early 1951, Los Alamos scientists Edward Teller and Stanislaw Ulam devised a breakthrough that would lead to the hydrogen bomb [1]. Their design gave the United States an initial advantage in the Cold War, though comparable progress was soon achieved independently in the Soviet Union and the United Kingdom.
Andrew M. Irvin, Ehab Hassan, Sebastian de Pascuale, Mark Cianciosa, Rhea L. Barnett, Livia Casali
Fusion Science and Technology | Volume 82 | Number 1 | January-February 2026 | Pages 64-78
Research Article | doi.org/10.1080/15361055.2025.2476829
Articles are hosted by Taylor and Francis Online.
The complex and iterative nature of plasma scenario optimization in fusion devices necessitates the use of reduced models in early stages of the design process to filter through a large parameter space in an efficient manner. Ray-tracing codes, such as TORAY, offer considerable advantages in run time for electron cyclotron (EC) heating and current drive (H/CD) cases over full-wave codes while maintaining a high degree of fidelity. We deploy the Fusion Reactor Design and Assessment (FREDA)–TokDesigner workflow to enable training of a surrogate model for EC H/CD radial profiles based on the TORAY ray-tracing code, coupled to the Integrated Plasma Simulator (IPS)–FASTRAN framework. The surrogate model is trained to predict key H/CD profile characteristics for EC cases based on a subset of plasma and EC launcher parameters for a Compact Advanced Tokamak (CAT) design point. The CAT was selected as a baseline to assess the performance of the surrogate model trained in the fusion pilot plant regime. The surrogate model is able to accomplish this an order of magnitude faster than TORAY coupled to IPS-FASTRAN while still maintaining a high level of accuracy. The surrogate model demonstrates invertibility, being able to solve the inverse problem to generate an accurate parameter space for a set of desired H/CD profile characteristics.