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 Nuclear Energy Conference & Expo (NECX)
August 24–27, 2026
Dallas, TX|Hilton Anatole
Latest Magazine Issues
Jun 2026
Jan 2026
2026
Latest Journal Issues
Nuclear Science and Engineering
July 2026
Nuclear Technology
Fusion Science and Technology
May 2026
Latest News
Breaking ground on a new approach to construction
The drive to Kairos Power’s reactor demonstration site in Oak Ridge, Tenn., is not only scenic—it’s historic. Nearly 85 years ago, roughly 30,000 construction workers transformed orchards and farmland into a key Manhattan Project site. Depending on your route, you may pass by one of the three gatehouses that were once military checkpoints controlling access to Atomic Energy Commission production facilities.
Albert E. Evans, M. S. Krick
Nuclear Science and Engineering | Volume 62 | Number 4 | April 1977 | Pages 652-659
Technical Paper | doi.org/10.13182/NSE77-A15208
Articles are hosted by Taylor and Francis Online.
A 3He neutron spectrometer has been used to measure the energy spectra of delayed neutrons in equilibrium with fission induced by sub-MeV neutrons incident upon 235U, 238U, and 239Pu. Full contribution of shorter lived delayed neutron groups not previously measured was ensured by bombarding samples for 35 out of every 100 ms and measuring delayed neutrons for 40 ms between each bombarding pulse. Results show delayed neutron spectra of somewhat higher average energy than have previously been reported. Examination of the energy end points of delayed neutron emitters as a function of precursor half-life shows that the higher average delayed neutron energies are probably due to the inclusion of neutrons from the shorter lived precursors.