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.
K. Takeuchi, S. Tanaka, M. Kinno
Nuclear Science and Engineering | Volume 78 | Number 3 | July 1981 | Pages 273-283
Technical Paper | doi.org/10.13182/NSE81-A20304
Articles are hosted by Taylor and Francis Online.
For the transport calculation of gamma rays including bremsstrahlung, an improvement is made in the PALLAS-PL, SP discrete ordinates direct-integration code to enable evaluation of bremsstrahlung. The electrons resulting from Compton scattering, pair production, and the photoelectric effect are individually evaluated based on the primary gamma-ray flux calculated with the code. Bremsstrahlung production is then calculated by applying the continuous electron slowing down model. For this purpose, both the electron stopping power and the differential cross section for bremsstrahlung production are evaluated. Comparisons of PALLAS calculations with experiments are presented to test the validity of this code and method. As a result, it has been observed that the PALLAS calculations result in fairly good agreement with experiments, except for some discrepancies at energies below ∼0.7 MeV in the energy spectrum transmitted through lead and iron from a plane isotropic 6.2-MeV gamma-ray source. There is agreement also with another experiment on the attenuation by lead of transmission dose ∼8-MeV gamma rays in a normally incident from a plane monodirectional source. Further, there is agreement with the energy spectrum in lead calculated by a moments method for a plane monodirectional 8-MeV source without inclusion of secondary photons. Also presented are calculations of buildup factors and of energy spectra, including the contribution of bremsstrahlung, for a plane monodirectional beam of 8-MeV gamma rays normally incident on lead and on tungsten.
