Intro To Radtech. X-ray Production Flashcards
What are x-rays?
A group or rays belonging to the electromagnetic spectrum
Electromagnetic spectrum measures in…
Wavelengths and light
What is radioactivity?
Radioactivity is the process of decay.
Everything around us is radioactive
Sine waves travel at what speed
The speed of light
What is the speed of light?
186,000 miles per second
3x10^8 meters per second
3x10^10 centimeters per second
C=constant
EM wavelengths are measured in
The distance between two successive crests in a wave
Lamda
EM Frequency is measure in
The time between each crest
Nu
Wavelength and frequency of Em waves are
Inversely proportional
Speed of light = wavelength x frequency
What is the crest of a wave?
The highest point in the wave
What is the trough of a wave
The lowest point
The wavelength of a wave
Crest to crest or trough to trough or center to center.
Distance between
What is the wave height?
Distance between the crest and its neighboring trough
What is amplitude?
The amount that the wave has been displaced from its median position.
Half of the wave height
What is the undisturbed surface of a wave
The middle line of the wavelength
What is frequency?
The number of crests or troughs that pass through during a specific time interval.
Inverse of period
What is period?
.the length of time it takes to complete one cycle
X-Ray beams are
Heterogenous
Meaning different energies
Average- very short wavelength
Useful range is 0.1A through 0.5A
What are the two theories on properties of x-rays?
Wave concept
Particle concept
What is the wave concept on properties of x-rays
It explains how they move through space. And yet travel in a vacuum
What is the particle concept on properties of x-rays?
Explains how they can interact with matter as though they were particles.
Define mathematical constant
- constant: a non-varying value
- variable: changing value
- constant, in a formula, usually denoted by a letter, such as c for the speed of light
- or planck’s constant: the letter h
Is there a relationship between photon energy and frequency?
- energy = plancks constant x frequency
- plancks constant = 6.63x10^-34 joule-seconds
Symbol is h
As frequency increases, photon energy increases
Who discovered x-rays?
Wilhelm Conrad Roentgen
November 8, 1895
Discovered by accident
Observed by 12 other scientists previously
Roentgen identified all of the properties of x-rays less than a month after his discovery
Part of university of wurzburg
What is the first known medical radiograph?
A wrist x-ray performed on February 3, 1896 at Dartmouth college
What conditions are needed for x-ray production?
- separation of electrons
- high-speed electrons
- sudden stopping of electrons
- concentration(focusing) of electrons
Separation of electrons
Thermionic emission
Heating of the tungsten filament
Creates electron cloud aka space charge
All x-Ray tubes are…
Dual focus
Two filaments used one at a time
One wired with high voltage and one with low
Space charge
“Electron cloud”
Space charge effect
Limits the number of electrons present in the space charge
Due to the negative charge on the focusing cup, forcing the electrons together
In spite of the electrostatic repulsion the electrons have for each other