I am new to this subject and texts that I have read suggest that with an independent source, independent of neutron flux, that there are a multitude of equalibrium (dn/dt = 0 ) neutron population levels for Keff < 1.
For each distinct value of keff < 1 there is distinct value of neutron...
Consider a reactor being held sub-critical, Keff < 1, by control rods. The reactor has heavy water reflector and has been operatored for some time prior to the current state (we got Photo Neutrons). Keff is then bought to
1.
It seems to me, for Keff = 1 the neutron population should be...