Summary Lecture 1. Radiation Physics Flashcards
What is matter?
Anything with mass and occupies space.
What is an atom?
Basic unit of matter.
What does the nucleus contain?
Protons (+) and neutrons (neutral).
What are electrons?
Negatively charged particles orbiting the nucleus.
What is the atomic number (Z)?
Number of protons; determines the element.
What is the atomic mass (A)?
Total of protons + neutrons.
What is binding energy?
Energy required to remove an electron from its orbital shell.
Where are electrons more tightly bound?
Inner shell electrons (e.g., K-shell).
What increases binding energy?
Higher atomic number (Z) due to more protons.
What is ionization?
Removal of an electron from a neutral atom, creating an ion pair.
What is needed for ionization?
External energy exceeding the electron’s binding energy.
What is radiation?
Transmission of energy through space or matter.
What are the two forms of radiation?
Wave theory and quantum theory.
Describe wave theory.
Radiation travels as waves (no mass) at the speed of light.
What determines high energy in wave theory?
Short wavelength and high frequency.
Describe quantum theory.
Radiation consists of discrete energy packets (photons).
What determines high energy in quantum theory?
Short wavelength and high frequency.
What is ionizing radiation?
Radiation with enough energy to ionize atoms.
Give examples of ionizing radiation.
X-rays, gamma rays, alpha particles, beta particles, neutrons, protons.
What is non-ionizing radiation?
Radiation lacking sufficient energy to ionize atoms.
What is Linear Energy Transfer (LET)?
Rate of energy loss by radiation as it travels through matter.
What is the penetration of high LET radiation?
Less penetration, short range.
What is the penetration of low LET radiation?
Greater penetration, longer range.
What are X-rays?
Photons with no mass or charge, traveling at the speed of light.
What are the properties of X-rays?
Invisible, weightless, neutral, travel in straight lines, ionize matter.
What is excitation?
Transfer of energy to an electron, raising it to a higher energy level without ejection.
What happens after excitation?
Electron returns to ground state, releasing energy.
