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
Fusion Science and Technology
August 2025
Latest News
Powering the future: How the DOE is fueling nuclear fuel cycle research and development
As global interest in nuclear energy surges, the United States must remain at the forefront of research and development to ensure national energy security, advance nuclear technologies, and promote international cooperation on safety and nonproliferation. A crucial step in achieving this is analyzing how funding and resources are allocated to better understand how to direct future research and development. The Department of Energy has spearheaded this effort by funding hundreds of research projects across the country through the Nuclear Energy University Program (NEUP). This initiative has empowered dozens of universities to collaborate toward a nuclear-friendly future.
A. Dubi, T. Elperin, Donald J. Dudziak
Nuclear Science and Engineering | Volume 80 | Number 1 | January 1982 | Pages 139-161
Technical Paper | doi.org/10.13182/NSE82-A21411
Articles are hosted by Taylor and Francis Online.
Through a direct statistical approach, analytic expressions are derived for the second moment, the variance ratio, and benefit functions of a model for n-surface geometric splitting. The model is general in that it can be applied to many geometric and material conditions, energy dependence, and biasing methods besides splitting. The model applies to any detector, provided that the detector region is separated from the source region. The model has the following limitations: (a) every source particle reaching the detector must cross all splitting surfaces, (b) particles are allowed to split only once on each surface, (c) weight-dependent biasing schemes are not included, and (d) reactions that bifurcate the particle are excluded. The derived expressions depend linearly on n unknown constants that are bulk properties of the medium in a given problem. These constants may be estimated approximately from one small sample run invoking the point-surface approximation or from (n + 1) consecutive small sample runs. Numerical examples are given in verification of the theory, and the possibility of using the expressions in an in-code optimization or self-optimizing code is discussed.