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.
Division Spotlight
Nuclear Installations Safety
Devoted specifically to the safety of nuclear installations and the health and safety of the public, this division seeks a better understanding of the role of safety in the design, construction and operation of nuclear installation facilities. The division also promotes engineering and scientific technology advancement associated with the safety of such facilities.
Meeting Spotlight
ANS Student Conference 2025
April 3–5, 2025
Albuquerque, NM|The University of New Mexico
Standards Program
The Standards Committee is responsible for the development and maintenance of voluntary consensus standards that address the design, analysis, and operation of components, systems, and facilities related to the application of nuclear science and technology. Find out What’s New, check out the Standards Store, or Get Involved today!
Latest Magazine Issues
Apr 2025
Jan 2025
Latest Journal Issues
Nuclear Science and Engineering
May 2025
Nuclear Technology
April 2025
Fusion Science and Technology
Latest News
First astatine-labeled compound shipped in the U.S.
The Department of Energy’s National Isotope Development Center (NIDC) on March 31 announced the successful long-distance shipment in the United States of a biologically active compound labeled with the medical radioisotope astatine-211 (At-211). Because previous shipments have included only the “bare” isotope, the NIDC has described the development as “unleashing medical innovation.”
J. D. Galambos, Y.-K. Martin Peng
Fusion Science and Technology | Volume 19 | Number 1 | January 1991 | Pages 31-42
Technical Paper | Fusion Fuel Cycle | doi.org/10.13182/FST91-A29313
Articles are hosted by Taylor and Francis Online.
The D-3He ignition and burn criteria for tokamaks and spherical torus reactors are examined in a global analysis with profile corrections. Particle confinement and ash buildup effects are included with the power balance, which results in an increased sensitivity of the ignition criteria to losses via bremsstrahlung and synchrotron radiation. Plasma beta scaling via an ɛβp limit provides the needed aspect ratio (A) dependence and permits an analysis in all A values of the first and second stability regimes. Energy confinement time (τE) associated with particle diffusion (τp) and energy conduction (τc) is used. The ignition condition for minimum nτE is found to be sensitive to beta but not to the magnetic field. Steady-state burn in second stability tokamaks (ξβp ≥ 0.6) at high A (>4) with average synchrotron wall reflectivities below 95% requires nτE above 5 × 1021 m−3 · s or strong plasma elongation (κ > 3). Ignition in a spherical torus can be achieved with wall reflectivities below 80% and at nτE ≤ 1021 m−3 · s, without requiring strong plasma shaping or ɛβp > 0.6. The need to minimize nτE for ignition and burn strongly limits the synchrotron radiation loss to <20% of the fusion power for all values of A. Synchrotron power fractions can be increased, but only to 40%, due to an upper bound on nτE. Further increases of this fraction can be obtained only by assuming preferential ash removal.