Radiation Flashcards
What are the fuel rods in a nuclear reactor made from?
Uranium
What are the control rods in a nuclear reactor made from?
Boron Cadmium
What is the moderator of a nuclear reactor made from?
Heavy Water Graphite
What is the shielding of a nuclear reactor made from?
Lead
What is the name of the process occuring in a nuclear reactor?
Fission Nuclear Fission
A nuclear reactor is self-sustaining. What is this type of reaction called?
Chain reaction
What is used to trigger a nuclear fission reaction?
Slow moving neutron
How many neutrons (on average) are produced by a single nuclear fission?
3
What are the nuclei produced by nuclei fission called?
Daughter nuclei
What does the fuel rod do in a nuclear reactor?
Holds the fuel to allow the reaction to take place
What does the moderator in a nuclear reactor do?
Reduces the speed of neutrons to increase the rate of reaction
What do the control rods in a nuclear reactor do?
Removes neutrons from the reactor to reduce the rate of reaction or stop the reaction.
Why is shielding necessary on a nuclear reactor?
Reactor material is radioactive. Radiation causes cancer. Radiation is very penetrating.
What form does nuclear fission convert energy into?
Kinetic
Explain how nuclear fission can lead to a chain reaction.
Neutrons released. Slowed by moderator. Absorbed by OTHER uranium nuclei. Causing further fissions.
State a source of background radiation.
Rocks Radon Cosmic rays Medical sources Carbon atoms in living creatures
How do I correct an experiment for background radiation.
Do experiment without radioactive source. Measure background count. Repeat and take an average. Subtract this average value from the experimental values.
Why do we use beta sources as medical tracers?
Penetration depth large enough to get through the skin and be detected outside the body.
What material blocks alpha radiation?
Paper Skin
What material blocks beta radiation?
Aluminium Foil
What material reduces gamma radiation?
Lead Lots of concrete
Which radiation has the largest penetration depth?
Gamma
Which radiation has the shortest penetration depth?
Alpha
Which radiation is the most ionising?
Alpha
Which radiation is the least ionising?
Gamma
What is an isotope?
An atom with the same number of protons but a different number of neutrons.
What is the mass number of a nucleus?
The number of protons plus neutrons
What is the atomic number of a nucleus?
The number of protons.
An isotope alpha decays. What happens to the mass number?
-4
An isotope alpha decays. What happens to the proton number?
-2
An isotope beta decays. What happens to the mass number?
Nothing
An isotope beta decays. What happens to the proton number?
1
What is an alpha particle?
2 protons 2 neutrons bound together He-4 nucleus
What is a beta particle?
electron
What is gamma radiation?
High frequency EM radiation
What is a non-medical application of alpha?
A smoke detector
Why is alpha suitable for use in smoke detectors?
It is blocked by smoke but not by air.
