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
Radiation Protection & Shielding
The Radiation Protection and Shielding Division is developing and promoting radiation protection and shielding aspects of nuclear science and technology — including interaction of nuclear radiation with materials and biological systems, instruments and techniques for the measurement of nuclear radiation fields, and radiation shield design and evaluation.
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
Mar 2025
Jul 2024
Latest Journal Issues
Nuclear Science and Engineering
March 2025
Nuclear Technology
Fusion Science and Technology
April 2025
Latest News
Nuclear News 40 Under 40 discuss the future of nuclear
Seven members of the inaugural Nuclear News 40 Under 40 came together on March 4 to discuss the current state of nuclear energy and what the future might hold for science, industry, and the public in terms of nuclear development.
To hear more insights from this talented group of young professionals, watch the “40 Under 40 Roundtable: Perspectives from Nuclear’s Rising Stars” on the ANS website.
G. Marleau, A. Hebert
Nuclear Science and Engineering | Volume 111 | Number 3 | July 1992 | Pages 257-270
Technical Paper | doi.org/10.13182/NSE92-A23939
Articles are hosted by Taylor and Francis Online.
The J± technique is an approximation of the collision probability (CP) method in which a probability matrix is associated with each homogeneous region, and then, these regions are coupled using an interface current technique. The main advantages of the J± technique are its speed and the fact that the probability matrix associated with each region is completely decoupled from its environment. Previous work using the DP0 approximation of the J± technique has been carried out for cluster geometries. Here, the DP1 approximation is investigated, and in addition to the uniform angular flux contribution, linearly anisotropic contributions are also considered. For cluster geometries, this results in an approximation for the angular fluxes of the form ψ(rs,Ω) = a + b(Ω.N), where a and b are expansion coefficients to be determined, Ω is the neutron angular direction, and N is normal at surface s. A surf ace fractioning correction is also introduced to remove the diffraction effect that arises when using the J± method in two-dimensional geometries. The results obtained by means of the DPI approximation are now very close to those of the CP method.