NEEP 541
Fall 2007
Homework #3
1. The equation for the concentration of vacancies formed by irradiation is given by:
dCv
=K 0 - K iv C iCv - K vs Cs Cv
dt
a) Each term represents a creation or loss of a vacancy in the lattice. Describe physically what
eac

NEEP 541
Fall 2009
Exam #2
1. List five different point (zero dimensional) defects [5 points]
2. Starting with a metal with a zero sink density, you follow the microstructure and notice that
dislocation loops and voids form over time. What does this tell

NEEP 541
Fall 2009
Exam #1
1. Why is stress relaxation a concern in a nuclear reactor? [5 points]
2. Describe how a gamma ray could displace an atom [5 points]
3. For the collision between two particles with identical mass described by a hard sphere
poten

1. If an alloy swells by increasing the radius of constant density voids, by how much does a
doubling of the swelling harden the alloy? For this scenario, is the swelling or the hardening
from the voids more of a concern?
2. An Inconel-718 bolt is used to

1. A Ni-18Cr alloy is irradiated at 400C.
a. The chromium concentration is measured at the grain boundary and is found to deplete.
What is the sign of the determinant for chromium?
b. The bulk concentration of nickel decreases from 82 to 70 wt. %. Assumin

1. The equation describing the change in vacancy concentration under irradiation is given by:
Describe, for each variable, if the variable is a function of the material being irradiated, the
irradiation conditions, or both.
2. The equation for the concent

NEEP 541
Fall 2009
Homework #2
1. Assume the stopping power can be described by the following function:
1 where C and K are constants
S K 2
C E
a. What do each of the two terms represent? What approximations are inherent in this
formulation?
b. Derive an

NEEP 541
Fall 2009
Homework #1
1. A 1 MeV iron atom (particle 1) collides with an initially stationary iron atom (particle 2).
a. Prior to the collision, what is the center-of-mass velocity?
b. Prior to the collision, what is the speed of particle 2 relat

NEEP 541
Fall 2011
Homework #2
1. For Coulomb interactions, are high or low angle collisions more likely? Explain why.
2. Assume the stopping power can be described by the following function:
where C and K are constants
a. What do each of the two terms re

NEEP 541 Binary Collisions to Damage
Review
Fall 2011
Todd Allen
Radiation Damage Process
Primary radiation damage caused by energetic particle
interacting with lattice atoms
Diffusion of defects created by primary damage radiation
Creation of radiatio

NEEP 541
Fall 2011
Homework #2
1. For Coulomb interactions, are high or low angle collisions more likely? Explain why.
2. Assume the stopping power can be described by the following function:
1 where C and K are constants
S K 2
C E
a. What do each of the

NEEP 541
Fall 2007
Homework #4
1. For a binary alloy, the radiation-induced segregation determinant is given by:
a. If the determinant is positive, does atom A enrich or deplete at the sink surface? Explain.
b. If the diffusion of atom A in the vacancy fl

NEEP 541
Fall 2007
Homework #4
1. For a binary alloy, the radiation-induced segregation determinant is given by:
a. If the determinant is positive, does atom A enrich or deplete at the sink surface? Explain.
b. If the diffusion of atom A in the vacancy fl

NEEP 541
Fall 2011
Homework #1
1. Three separate particles travel through a pure iron slab, specifically 1 MeV neutrons, 1 MeV
gammas, and 1 MeV electrons. For each:
a. Calculate the maximum possible energy transfer to an Fe atom from a 1 MeV neutron,
a 1

NEEP 541
Fall 2011
Homework #1
1. Three separate particles travel through a pure iron slab, specifically 1 MeV neutrons, 1 MeV
gammas, and 1 MeV electrons. For each:
a. Calculate the maximum possible energy transfer to an Fe atom from a 1 MeV neutron,
a 1

NEEP 541
Fall 2007
Homework #3
1. The equation for the concentration of vacancies formed by irradiation is given by:
dCv
=K 0 - K iv C iCv - K vs Cs Cv
dt
a) Each term represents a creation or loss of a vacancy in the lattice. Describe physically what
eac

NEEP 541
Fall 2009
Exam #3
1. Why does cold-working reduce the rate at which void swelling develops in austenitic steels?
[5 points]
2. A reactor pressure vessel can become brittle during service, but the same material does not
become brittle if held at r