Lecture 3

Question 1

Given the non-leakage probablity, what is the equation for k?

Answer 1

Question 2

Equation for caputre-to-fission ratio?

Answer 2

Question 3

The capture-to-fission ratio ratio decreases sharply above ____ keV

Answer 3

100

Question 4

The number of neutrons produced per fission ______ above 1 MeV

Answer 4

increases rapidly

Question 5

What is the equation for the ratio of fission neutrons produced to neutrons absorbed)?

Answer 5

Question 6

What is the equation for isotopic eta?

Answer 6

Question 7

Answer 7

Question 8

Equation for fuel eta (using fissile enrichment ratio)

Answer 8

Question 9

Fast reactors must have a U-235 enrichment percent of at least

Answer 9

10%

Question 10

The average fractional energy loss from isotropic elastic scattering is given by

Answer 10

Question 11

Average slowing down decrement

Answer 11

Question 12

Average slowing down power

Answer 12

Question 13

Average slowing down ratio

Answer 13

Question 14

define

Answer 14

number of neutrons/cm^3 with energies between E and E+dE

Question 15

define

Answer 15

total number of neutrons / cm^3

Question 16

define φ(E)dE

Answer 16

total distance traveled during one second by all neutrons with energies E and E+dE in 1 cm^3

Question 17

What is the equation for φ(E)?

Answer 17

Question 18

Define

Answer 18

probablity/cm of flight of a neutron with energy E undergoing a reaction of type x

Question 19

Define

Answer 19

probable number of colllisions of type x /s-cm^3 for neutrons with energies between E and E+dE

Question 20

Define

Answer 20

probable number of collisions of type x /s-cm^3 of all neutrons

Question 21

Fill in the blanks

Answer 21

Question 22

define q(E)

Answer 22

numer of neutrons slowing down past energy E /s/cm^3

Question 23

Primary form of absorption comes from

Answer 23

the resonance cross sections

Question 24

Between resonances, the absorption cross sections are

Answer 24

small enough to be ignored

Question 25

In the intermediate range below the fission spectrum

Answer 25

Question 26

In the intermediate range below the ifssion spectrum ϕ(E) =

Answer 26

Question 27

The flux is no longer proportional to 1/E when what kind of material is present?

Answer 27

resonance absorber

Question 28

What is the equation for ϕ(E) using the the narrow resonance approximation?

Answer 28

Question 29

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.

Answer 29

reduces reduces aids

Question 30

Absorption cross sections in the _____ range are approximately 1/v

Answer 30

thermal

Question 31

Equation for thermal cross section averages

Answer 31

Question 32

In many cases, thermal scattering cross sections are _____ of energy

Answer 32

independent

Question 33

At thermal energies, the binding of atoms to molecules or within crystal lattices can significantly affect

Answer 33

thermal scattering cross sections

Question 34

Equation for number of fission neutrons produced

Answer 34

Question 35

Equation for number of neutrons absorbed

Answer 35

Question 36

Infinite multiplicaton factor (given cross sections)

Answer 36