DHY 102 Radiation Physics Lecture 1

Who discovered the x-ray?

Wilhelm Roentgen

What year was the first x-ray of the human body taken?

1895

Define radiation.

energy carried by waves of particles

Define x-radiation.

energy that can penetrate substances to record images

Define radiology.

science of radiation in medicine

Define radiograph.

2D picture of 3D object

Give 4 examples of the uses of dental radiographs.

detect diseases, lesions, evaluate growth, provide information

Give the 2 steps that follow a dental radiograph.

clinical treatment plan, comprehensive patient care

Give the term that “occupies space and has mass.”

matter

Give the term for the fundamental unit of matter.

atom

What has the ability to do work and overcome resistance?

energy

What is inside the atomic nucleus?

protons and neutrons

Which shell around the nucleus has the highest binding energy?

closest

Ionization causes the atom to lose an electron forming an ___ ____.

The atom is the _____ ion, the ejected electron is the _____ ion.

ion pair, positive, negative

______ is required to remove an electron from an atom.

energy

What type of radiation is not capable of producing ions?

Non-ionizing

What type of radiation is capable of producing ions by removing electron from an atom?

Ionizing

Give the 2 groups of ionizing radiation.

Particulate, electromagnetic

Which ionizing radiation deals with tiny particles of matter?

Particulate

Which ionizing radiation deals with x-rays?

Electromagnetic

What is this term?

wavelength

The shorter the wavelength, the ____ the energy. The longer the wavelength, the ____ the energy.

higher, lower

Define frequency.

number of wavelengths passing in a period of time

Give the wavelength and frequency.

long, low

Give the wavelength and frequency.

short, high

What is 1?

Control Panel

What is 2?

Extension arm

What is 3?

Tubehead

What kind of wavelengths are harmful to a patient and not useful in radiography?

long and low energy

What is the purpose of a filter?

Absorbs long wavelengths

What is the center rectangular part of the x-ray machine?

Tube

What is this part of the machine?

Collimation

What is the purpose of the collimation?

controls size of beam

What is the collimation made of?

lead

Give the name.

Position indicating device

The cathode is the _____ electrode.

negative

The anode is the _____ electrode.

positive

What does the cathode do?

supplies electrons

What does the anode do?

converts electrons from cathode into photons

What are the 2 components of the cathode?

tungsten filament, molybdenum cup

What are the 2 components of the anode?

tungsten target, copper stem

Give the two types of radiation that are produced by the reaction of the electrons striking the tungsten target:

General, characteristic

How is general radiation produced?

fast electron hits nucleus or comes close

General radiation will ____ the electron and an x-ray photon is produced.

slow

How commonly is general radiation used for x-ray production?

70%

How is characteristic radiation produced?

speeding electron breaks another electron from inner shell

This kind of radiation is produced with the

penetrating beam that is produced at the target of

the anode…

Primary

This kind of radiation is produced when the primary

beam reacts with matter…

Secondary

This kind of radiation is produced when an x-ray has been deflected from its path by interaction with matter…

Scatter

What kind of x-ray interaction is this?

none

What kind of x-ray interaction is this?

Photoelectric effect

What kind of x-ray interaction is this?

Compton scatter

What kind of x-ray interaction is this?

Coherent scatter