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 Annual Conference
May 31–June 3, 2026
Denver, CO|Sheraton Denver
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
Dec 2025
Jul 2025
Latest Journal Issues
Nuclear Science and Engineering
December 2025
Nuclear Technology
Fusion Science and Technology
November 2025
Latest News
3D-printed tool at SRS makes quicker work of tank waste sampling
A 3D-printed tool has been developed at the Department of Energy’s Savannah River Site in South Carolina that can eliminate months from the job of radioactive tank waste sampling.
William W. Wadman III
Nuclear Science and Engineering | Volume 35 | Number 2 | February 1969 | Pages 220-226
Technical Paper | doi.org/10.13182/NSE69-A21137
Articles are hosted by Taylor and Francis Online.
The angular distribution, yield, spectra, and attenuation of fast neutrons from the alpha-particle bombardment of a thick elemental tantalum target have been measured. Data obtained by using threshold energy detectors and thermal-neutron detectors were reduced to neutron spectra with the computer program FLUXPOS. Thermal-neutron activation foils were placed in the shielding at 6-in. intervals to determine the neutron attenuation profiles at 0, 75, and 90° from the target. Data show that the neutron spectral slope becomes steeper and the relaxation length (1/e attenuation thickness) decreases with increasing angle.