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
Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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
Aug 2025
Jan 2025
Latest Journal Issues
Nuclear Science and Engineering
September 2025
Nuclear Technology
August 2025
Fusion Science and Technology
Latest News
Ribbon-cutting scheduled for Advanced Manufacturing Collaborative
Energy Secretary Chris Wright will attend the opening of the Advanced Manufacturing Collaborative in Aiken, S.C., on August 7. Wright will deliver remarks and join Savannah River National Laboratory leadership and partners for a ribbon-cutting ceremony.
Jingshang Zhang
Nuclear Science and Engineering | Volume 114 | Number 1 | May 1993 | Pages 55-63
Technical Paper | doi.org/10.13182/NSE93-3
Articles are hosted by Taylor and Francis Online.
The master equation theory of precompound and compound nuclear reactions has been generalized to include the conservation of angular momentum and parity. Based on this improved semi-classical theory, the UNF code has been developed as a tool for calculating nucleon-induced reaction cross sections and double-differential cross sections at incident neutron energies below 20 MeV. It is demonstrated that the code contains the Hauser-Feshbach model and the exciton models as the limiting cases. The unified treatment of equilibrium and pre-equilibrium reaction processes includes the introduction of composite particle formation factors in calculations of pickup-type composite particle emissions. A method to calculate the double-differential cross sections for all kinds of particles is proposed based on the leading particle model.