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 Nuclear Energy Conference & Expo (NECX)
August 24–27, 2026
Dallas, TX|Hilton Anatole
Latest Magazine Issues
Jul 2026
Jan 2026
2026
Latest Journal Issues
Nuclear Science and Engineering
September 2026
Nuclear Technology
August 2026
Fusion Science and Technology
Latest News
In transition: Commercializing fusion power
Commercial fusion power is closer than ever. There are now around 30 U.S. fusion companies, several of which claim to be on track to connect to the grid as early as the 2030s.
Tokamak and laser inertial confinement approaches benefit from decades of research at facilities such as the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory and ITER, with alternative concepts including stellarator, magnetic mirror, and Z-pinch confinement also making notable progress as private and government funding for fusion increases.
Erkang Li
Nuclear Science and Engineering | Volume 85 | Number 1 | September 1983 | Pages 61-70
Technical Note | doi.org/10.13182/NSE83-A17153
Articles are hosted by Taylor and Francis Online.
A method for calculating the first-flight collision probabilities in an annular region containing identical cylindrical fuel rods is described. Based on the assumptions of flat isotropic neutron sources and isotropic incidence fluxes on boundary surfaces, 5 of the 15 probabilities in the annular region are calculated. By neutron conservation and the reciprocity theorem, the other 10 probabilities are obtained in terms of the first 5. The results are satisfactory in comparison to other existing theories. The method can be used in the treatment of a cluster-type fuel assembly.
