3: Flux and Current. B. Rouben McMaster University Course EP 4D03/6D03 Nuclear Reactor Analysis (Reactor Physics) 2012 Sept.-Dec. Contents. Concepts: Angular Neutron Flux, Angle-Integrated Flux Angular Neutron Current, Angle-Integrated Current Reaction rates. Neutron Density.
3: Flux and Current
Course EP 4D03/6D03
Nuclear Reactor Analysis
i.e. - units are, e.g., neutrons/cm3 ( n.cm-3).
Then neutron density
i.e., the product of neutron density n and speed υ.
(this can be thought of as summing
neutron beams over all directions)
(neutrons.cm-3*cm.s-1) = (n.cm-2.s-1)
Total flux = sum of all arrow lengths in unit volume
= total path length traversed by all neutrons in unit volume per unit time
If we want to sum all neutrons moving across the plane from one side to the other, we need to consider the range of .
For neutrons crossing the plane from below, is between 0 and /2 ( = cos = 0 to 1).
For neutrons crossing from above to below, is between /2 and ( = -1 to 0).