Lecture 3 Flashcards
Given the non-leakage probablity, what is the equation for k?
Equation for caputre-to-fission ratio?
The capture-to-fission ratio ratio decreases sharply above ____ keV
100
The number of neutrons produced per fission ______ above 1 MeV
increases rapidly
What is the equation for the ratio of fission neutrons produced to neutrons absorbed)?
What is the equation for isotopic eta?
Equation for fuel eta (using fissile enrichment ratio)
Fast reactors must have a U-235 enrichment percent of at least
10%
The average fractional energy loss from isotropic elastic scattering is given by
Average slowing down decrement
Average slowing down power
Average slowing down ratio
define
number of neutrons/cm^3 with energies between E and E+dE
define
total number of neutrons / cm^3
define φ(E)dE
total distance traveled during one second by all neutrons with energies E and E+dE in 1 cm^3
What is the equation for φ(E)?
Define
probablity/cm of flight of a neutron with energy E undergoing a reaction of type x
Define
probable number of colllisions of type x /s-cm^3 for neutrons with energies between E and E+dE
Define
probable number of collisions of type x /s-cm^3 of all neutrons
Fill in the blanks
define q(E)
numer of neutrons slowing down past energy E /s/cm^3
Primary form of absorption comes from
the resonance cross sections
Between resonances, the absorption cross sections are
small enough to be ignored
In the intermediate range below the fission spectrum
In the intermediate range below the ifssion spectrum ϕ(E) =
The flux is no longer proportional to 1/E when what kind of material is present?
resonance absorber
What is the equation for ϕ(E) using the the narrow resonance approximation?
Since self-shielding ____ the flux where the absorption cross section is large, it _____ overall neutron losses to absorption and thus ____ the propogation of the chain reaction.
reduces
reduces
aids
Absorption cross sections in the _____ range are approximately 1/v
thermal
Equation for thermal cross section averages
In many cases, thermal scattering cross sections are _____ of energy
independent
At thermal energies, the binding of atoms to molecules or within crystal lattices can significantly affect
thermal scattering cross sections
Equation for number of fission neutrons produced
Equation for number of neutrons absorbed
Infinite multiplicaton factor (given cross sections)
