Topic 1: Radiation Flashcards
When does radiation occur?
It occurs when energy propagates through space
In what form is radiation transmitted?
waves or particles
How does electromagnetic radiation travel and what do they travel as
they travel in waves as visible light, radio waves, x-rays and gamma
What is radiation?
the transmission of energy in waves/particles through space or a medium
All forms of _______ _____ travel as waves
electromagnetic radiation
Some types of atomic decay lead to…
/particle radiation
What are sound waves?
pressure fluctuations in a medium
What types of radiation are a result of kinetic energy?
Particle radiation and mechanical radiation
Examples of particle radiation
electrons, protons, neutrons, etc.
Examples of mechanical radiation
only state of motion is the propagation (ex. sound waves, ultrasound)
Does radiation as a result of electromagnetic field require a medium?
No
What does radiation as a result of an electromagnetic field generate?
electric and magentic forces that act on surrounding particles with electromagnetic properties
How does propagation resulting of electromagnetic field travel?
Through transverse waves
How can radiation be classified?
In how they interact with matter and the properties of the radiation itself
What are the types of radiation classified in how it interacts with matter?
Non-ionizing and ionizing radiation
What is non-ionizing radiation?
all mechanical waves, every electromagnetic wave with frequency lower than UV
What is ionizing radiation?
high frequency radiation that transfers energy to electrons of a molecule….. turns the atom in an ion; can cause harm to living DNA: used for cancer treatment and medical imaging
What is radiant power, and what is the equation?
the amount of energy over time- measured in Watts: P=ΔE/Δt
What is radiant emittance and what is the equation?
/radiant flux- describes the radiant energy emitted from a radiation source per unit area (direction is neglected) M=ΔP/ΔA in Watts/meters2
What is intensity and what is the equation to find it?
measures the strength of the radiant beam- measures the radiation being propagated J=ΔP/ΔA
What is attenuation?
the gradual loss of flux intensity while passing through a medium
What is the attenuation of radiation law?
J=Jo * e^ -μx stating that the attenuation coefficient (μ) is dependent on density, type of radiation and interaction of the radiation and medium (x is thickness of material)
Unit of radiation POWER
Watts (joules/second)
Unit of radiation ENERGY
Joules
Unit of radiation EMITTANCE
W per meter^2
Unit of radiation INTENSITY
W/m^2
Unit of IRRADIANCE
W/m^2
What are simple laws of radiation?
Laws based on how radiation spreads. Useful when trying to find how to expose crops to more light, or avoiding radiation exposure
Radiation when spherically radiating outward from a point has an intensity of
1/r^2
