Nuclear Physics Exam 2

radioactive decay is when an __________ nucleus undergoes transformation, it is a ____________ process

unstable; spontaneous

decay constant is the fraction of atoms undergoing ________________________________ per unit time

radioactive decay

activity depends on ____________ __________ and ______ of _________

decay constant and number of atoms

half life is the time required to decay _____ of it’s _______ value

50%; initial value

a pre-calibration factor is multiplied by original activity to calculate?

activity that needs to be drawn at a specific time

the PCF is always?

greater than one!

it is possible to predict how _________ atoms will decay, but impossible to predict __________

many; which

if the half life is GREATER than 10¹⁰ years it is ___________

stable

if the half life is LESS than 10^-9 sec it is ____________

nonexistent

we can assume radioactivity is gone after _______ half lives.

10

Tp

physical half life

Tb

biological half life

how to calculate effective half life?

Tp * Tb/ Tp +Tb

sucessive decay is when ______________ nuclide transforms into _____________ nuclide

parent; daughter

in secular equilibrium, T1/2 P ______ T1/2 D! it is ___________!

GREATER; long

in transient equilibrium, T1/2 P _________ T/12 D! it is ___________!

GREATER, not as long!

when there is no equilibrium, the half life of the daughter is _______________ than the parent

GREATER

the stable isotopes in a radionuclide sample are called:

carriers

radionuclides can be produced by ___________, ___________, or _____________

reactors, accelerators, or generators

fission is ________ ____________

self sustaining

__________ cause fission, and fission creates _________

neutrons; neutrons

fission is ___________ free, has _______ specific activity, and is generally ______

carrier free, high SA, and B-

The "core" of a nuclear reactor typically contains a large amount of naturally occurring _______ and also enriched ______. The enriched uranium is fissile and can undergo a fission reaction.

U-238, U-235

________ ________ contain uranium- 235

fuel cells

What is used to slow down the neutrons in a reactor?

moderators

What can expose the fuel cells?

control rods

the accelerator is also know as the ____________

cyclotron

the accelerator is __________ rich, and decays via _____ and ______, it is NOT __________ free, and is more _____________-

proton, EC and B+, not carrier free, expsensive

nuclear transmutation is the conversion of one ___________ _________ to __________

chemical element to another

in nuclear transmutation, it goes from _________ to ________

stable to unstable

generators have a __________ ____________ of radioactive material

continual supply

The dees in an accelerator are:

metal electrodes

About how much energy does a particle gain when it jumps across the dees in a cyclotron?

30 kev