Chapter 31 - Nuclear Energy; Effects and Uses of Radiation

Transmutation

Changing from one element to another, also occurs during nuclear reactions

Nuclear Reaction

Occurs when a nucleus is struck by another nucleus or a simpler particle

Reaction Energy

Used to calculate the energy used/expelled when particle a hits nucleus X andturns into nucleus Y and particle b

Collision Cross Section

Used to predict the probability of certain nuclear reactions happening

Liquid Drop Model

A uranium-235 nucleus absorbs a neutron and becomes a compound nucleus, uranium-236

Fission Fragments

The resulting nuclei from a fission reaction

Moderator

A substance used to slow down neutrons as they usually travel too fast to be absorbed by uranium atoms

Enrichment

process used to increase the percentage of uranium-235 in a sample of uranium in order to increase the likelihood of a nuclear reaction

Critical Mass

The minimum mass of uranium required to achieve a self-sustaining reaction

Neutron Multiplication Factor

The average number of neutrons produces by a reaction,representedby f, a self-sustaining reaction must have a NMF of f ≥ 1

Nuclear Fusion

Bringing two nuclei together to build a larger nuclei

Magnetic Confinement

One such method developed to contain the high temperature plasma necessary for fusion, uses strong magnetic fields to keep the plasma suspended in air and rotate it to increase its kinetic energy

Lawson Criterion

A value that the product of ion density (ions/m^3) and confinement time, τ , must surpass in order to produce ignition of a fusion reaction, defined as 3 ∗ 1020s/m^3

Ionizing Radiation

Any type of radiation that can ionize an atom of any material

Dosimetry

The study of measuring dosage of radiation

Source Activity

The rate of nuclear decays per second from a source, unit is the curie

Absorbed Dose

Another method of measuring exposure to radiation, this measures the effect theradiation has on the absorbing material

Relative Biological Effectiveness

The number of rads or X-ray or γ radiation that produces thesame biological damage as 1 rad of the given radiation

Natural Radioactive Background

A source of radiation that averages 0.30 rem per year per personin the U.S.

Radiation Sickness

A disease caused by large doses of radiation, symptoms include loss of bodyhair and nausea

Radiation Therapy

A cancer treatment that works by focusing large amount of radiation on cancercells in order to destroy them

Tracer

A compound that incorporates a radioactive isotope and can be traced within the body

Auto radiography

Radioactive isotopes are tracked on film

Gamma Camera

Simultaneously record radioactivity at many points which can be displayed on a screen for ease of visualization

Single Photon Emission Computed Tomography (SPECT)

The process of using gamma cameras to detect radioactive intensity at many points

Positron Emission Tomography

Uses positron emitters in a compound that accumulates in asingle area to further observe it