Science
A subatomic particle that has a negative electrical charge.
What is an electron?
In a dental X-ray machine, electrons are accelerated toward this metal target, where their sudden slowing produces X-rays.
What is the tungsten target?
This term refers to the amount of time the X-ray tube is producing radiation during an exposure.
What is exposure time?
This protective garment may be used during dental X-rays to help reduce unnecessary radiation exposure to the body.
What is a lead apron?
This German physicist accidentally discovered X-rays while experimenting with cathode rays.
Who is Wilhelm Röntgen?
This process happens when X-rays have enough energy to remove electrons from atoms.
What is ionization?
The focusing cup has this electrical charge, which helps concentrate electrons released from the filament into a narrow stream directed toward the target.
What is a negative charge?
This part of a dental X-ray machine controls the amount of radiation produced by controlling the number of electrons traveling toward the target.
What is the mA (milliamperage) control?
This radiation safety principle means keeping a patient’s exposure “as low as reasonably achievable” while still getting a useful diagnostic image.
What is ALARA?
X-rays were discovered on this day in 1895 by Wilhelm Röntgen.
What is November 8, 1895?
This is the process in which electrons are released from the heated tungsten filament.
What is thermionic emission?
What is the purpose of the tungsten filament in the cathode?
What is producing electrons when heated?
This term describes the amount or strength of X-ray radiation produced by the X-ray beam.
What is intensity?
This type of radiation can bounce off the patient during an X-ray and expose the dental operator if proper safety precautions are not followed.
What is scatter radiation?
This device is used to measure the amount of radiation exposure produced by an X-ray machine.
What is a dosimeter?
This occurs when an X-ray photon transfers some or all of its energy to an electron in matter.
What is absorption?
This component increases the voltage needed to accelerate electrons from the cathode toward the anode.
What is the step-up transformer?
This term describes the amount of radiation energy deposited in a specific mass of tissue and is commonly expressed in gray.
What is absorbed dose?
When taking a dental X-ray, the operator should stand at least this far away from the patient to reduce exposure to radiation.
What is 6 feet?
A dental X-ray operator is standing 4 feet from the X-ray source. If they move to 12 feet away, what happens to the intensity of the radiation according to the inverse square law?
What is it decreases to 1/9 of the original intensity?
Although electrons strike the tungsten target, approximately this type of interaction produces the majority of diagnostic x-rays.
What is Bremsstrahlung radiation.
The thickness of a specified material that reduces the intensity by half.
What is the half-value layer?
This occurs when an X-ray photon collides with an electron, causing the photon to change direction and lose some of its energy.
What is Compton scatter?
Increasing the distance between the operator and the patient during an X-ray exposure dramatically reduces radiation exposure because intensity follows this mathematical relationship.
What is the inverse square law?
In this year, Christopher Columbus made his first voyage across the Atlantic Ocean.
What is 1492?