Nuclear and radiation good def

radioisotope

isotope that emits radiation due to unstable combination of protons and neutrons

isotope

atoms with the same number of protons but with different numbers of neutrons

fundamental force

force that cannot be explained in terms of the actions of other forces

gravity

acts between objects with mass

weak force

governs particle decay

electromagnetism

acts between electrically charged particles

strong force

binds quarks together

decay constant

probability that a radioisotope will decay in a given second

boson

force carriers

baryon

subatomic particle with 3 quarks

decay energy

output of energy from radioactive decay

half life

the average time it takes for activity to halve

activity

number of nuclei that decay each second

absorbed dose

energy deposited in 1kg of substance by radiation

quality factor

weighting of the biological impact

binding energy

energy required to separate nucleus into its constituent particles and also provides extra mass of nucleons to exist separately

mass defect

difference in mass between the reactants and products in a nuclear reaction. Mass defect is converted into energy.

fission

the splitting of large unstable atomic nuclei to form smaller ones

fusion

combining 2 smaller nuclei to create a larger one

annihilation

particle and antiparticle collide and disappear, releasing energy

hadron

particle that has 3 quarks or a quark and an antiquark pair

meson

quark and antiquark pair bound by gluon

antiparticle

particle that has equivalent mass, but opposite charge and quantum properties of normal matter

nucleon

particle located at nucleus of an atom

chain reaction

series of nuclear fissions that may be controlled or uncontrolled.

critical mass of fuel

minimum amount of fissile material in shape of sphere required to establish a self-sustaining chain reaction

subcritical

quantity of fissile material that it too small to sustain a chain reaction

supercritical

quantity of fissile material that is large enough to sustain a chain reaction

fuel rod

contains fissionable U235 to produce heat

control rod

absorbs excess neutrons

moderator

slows down fast neutrons into thermal speeds so that they can be absorbed by U235

coolant

extracts heat from reactor and stops meltdowns

reactor shielding

a thick concrete wall that protects worker from radiation

neutron flux

number of neutrons passing through at a time

background radiation

low level ionising radiation result of earth being radioactive, nuclear testing and nuclear accidents

dose equivalent

measure of biological damage inflicted on a tissue due to absorption of a defined quantity of radiation

atomic mass constant

equal to 1/12th the mass of a carbon-12 nucleus. = to 1.66x10^27 kg

core

part of nuclear reactor where fission occurs and thermal energy is produced

heavy water

water that has a higher than normal proportion of water molecules that contain deuterium

fission fragments

nuclides formed during nuclear fission, usually radioactive