A Delayed neutron precursor is a group of fission products that produce delayed neutrons. Half-lives, branching ratios, and neutron yields are difficult to measure. Therefore we typically only use 6 groups of isotopes. Here is an example of the delayed neutron precursor groups with a mean neutron generation time of \(\Lambda=5.0e-4\) s
| Group | \(\beta_i\) | \(\lambda_i(1/s)\) |
| 1 | 0.000285 | 0.0127 |
| 2 | 0.0015975 | 0.0317 |
| 3 | 0.001410 | 0.115 |
| 4 | 0.0030525 | 0.311 |
| 5 | 0.00096 | 1.40 |
| 6 | 0.000195 | 3.87 |
Sources
- [1] Nuclear Engineering Lectures, NE560 – Lecture 1: Intro to Kinetics and Dynamics, (Aug. 17, 2020). Accessed: May 25, 2023. [Online Video]. Available: https://www.youtube.com/watch?v=OPfowMUJCrk
- [2] H. Zhang, L. Zou, D. Andrs, H. Zhao, and R. Martineau, “POINT KINETICS CALCULATIONS WITH FULLY COUPLED THERMAL FLUIDS REACTIVITY FEEDBACK,” 2013.
Backlinks
Delayed Fission Neutrons
Mean Neutron Generation Time
Point Reactor Kinetics Model