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
January 2026
Nuclear Technology
December 2025
Fusion Science and Technology
November 2025
Latest News
From Capitol Hill: Nuclear is back, critical for America’s energy future
The U.S. House Energy and Commerce Subcommittee on Energy convened its first hearing of the year, “American Energy Dominance: Dawn of the New Nuclear Era,” on January 7, where lawmakers and industry leaders discussed how nuclear energy can help meet surging electricity demand driven by artificial intelligence, data centers, advanced manufacturing, and national security needs.
J. T. Hogan, D. L. Hillis, J.D. Galambos, N. A. Uckan, K. H. Dippel, K. H. Finken, R. A. Hulse, R. V. Budny
Fusion Science and Technology | Volume 19 | Number 3 | May 1991 | Pages 1509-1512
ITER | Proceedings of the Ninth Topical Meeting on the Technology of Fusion Energy (Oak Brook, Illinois, October 7-11, 1990) | doi.org/10.13182/FST91-A29555
Articles are hosted by Taylor and Francis Online.
Many studies have shown the importance of the ratio τHe/τE in determining the level of He ash accumulation in future reactor systems. Results of the first tokamak He removal experiments have been analyzed, and a first estimate of the ratio τHe/τE to be expected for future reactor systems has been made. The experiments were carried out for neutral-beam-heated plasmas in the TEXTOR tokamak at KFA Jülich. Helium was injected both as a short puff and continuously and subsequently extracted with the Advanced Limiter Test-II (ALT-II) pump limiter. The rate at which the He density decays has been determined with absolutely calibrated charge-exchange spectroscopy and compared with theoretical models, using the Multiple Impurity Species Transport (MIST) code. An analysis of energy confinement has been made with the Princeton Plasma Physics Laboratory (PPPL) TRANSP code, to distinguish beam from thermal confinement, especially for low-density cases. The ALT-II pump limiter system is found to exhaust the He with a maximum exhaust efficiency (eight pumps) of ∼8%. We find 1< τHe/τE < 3.3 for the database of cases analyzed to date. Analysis with the International Thermonuclear Experimental Reactor (ITER) TETRA systems code shows that these values would be adequate to achieve the required He concentration with the present ITER divertor He extraction system.