From b62a98fdeca727532767d9488bc24ec394a07ee9 Mon Sep 17 00:00:00 2001 From: Dane Sabo Date: Tue, 17 Sep 2024 19:29:05 -0400 Subject: [PATCH] vault backup: 2024-09-17 19:29:05 --- .../2024-09-17 Module 5 Nuclear Fission Basics.md | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/300s School/NUCE 2100 - Fundamentals of Nuclear Engineering/2024-09-17 Module 5 Nuclear Fission Basics.md b/300s School/NUCE 2100 - Fundamentals of Nuclear Engineering/2024-09-17 Module 5 Nuclear Fission Basics.md index 9e7c2215..f63eea2f 100644 --- a/300s School/NUCE 2100 - Fundamentals of Nuclear Engineering/2024-09-17 Module 5 Nuclear Fission Basics.md +++ b/300s School/NUCE 2100 - Fundamentals of Nuclear Engineering/2024-09-17 Module 5 Nuclear Fission Basics.md @@ -36,6 +36,8 @@ Rate of increase = Production - absorbed - leakage $$k = \frac{\text{Number of neutrons in one generation}}{\text{Number of neutrons in preceding generation}}$$ Measures how many neutrons produced by each neutron born. There are more formulas in the slides. K can be based on material properties -## Energy Dependence +## Energy Dependence and Moderating Fission is most efficiently caused by thermal neutrons (energy < 1eV), but neutrons from fission are born at something like \>2MeV. 7 orders of magnitude reduction -- usually kinetic losses by neutrons colliding with things. -Different neutron moderators require a different number of collisions to bring the energy down to thermal. The closer the mass is to that of a neutron, the better. Hydrogen is best, then beryllium, then carbon (graphite). \ No newline at end of file + +Different neutron moderators require a different number of collisions to bring the energy down to thermal. The closer the mass is to that of a neutron, the better. Hydrogen is best, then deuterium, then beryllium, then carbon (graphite). +