Equipment used in the production of x-rays Flashcards
Conditions necessary for the production of x-rays
- Source of electrons
- Acceleration of electrons
- Sudden stoppage of electrons against target material
What is the source for selecting kVp?
Autotransformer
Provides for the variation of voltage flowing in the x-ray circuit and applied to the x-ray tube
Autotransformer
Autotranformer operates on the principle of what?
Self-induction
Self-induction
Single winding of wire incorporates both the primary & secondary coils of the transformer
Prereading voltmeter indicates what?
the kilovoltage that will be flowing through the tube once the exposure is made
mAs timer measures what?
Measures the total tube current in the shortest amount of time
Where is the mAs timer located?
Located after the secondary coil of the high voltage tranformer
AEC stands for?
Automatic Exposure Control
What is the purpose of an AEC?
To provide consistency of radiographic quality
Explain how AEC works
Consists of flat ionization chambers that is between the patient and the receptor. Radiation passes through the ionization chamber & ionizes the gase contained inside. The level of ionization is directly proportional to the density that will appear on the image.
Falling load generator take advantage of what?
Short time capabilities & tube heat-loading potential
Explain Falling load generators
It calculates the most effecient method of obtaining the required mAs. When the max heat load is reached for that mA, the generator decreases the mA to the next lower level. The exposure continues at a progressivly lower level of mA for the shortest time possible until the mAs is reached.
Falling load generator uses the shortest time possible to obtain the mAs
Disadvantages of Falling load generators
Exams which require a long exposure (ex. breathing lateral T-spine) and Rapid sequence exposures in which heat build up in the tube may increase exposure times
Step-up tranformer AKA
High-voltage transformer
Step-up transformer consists of what and require what to operate?
Consists of primary & secondary coils and require alternating current to operate
Step up tranformer operates on what principle?
Mutural Inducton - A magnetic field surrounding a wire wih electricity flowing through it induces (causes) electricity to flow in a second wire placed within the force field
What does a rectifier do?
Changes alternating current from the step-up transformer to direct current
Milliammeter (mA meter) measures what?
Measures tube current in milliamperes
mA Control (filament circuit) regulates what?
The number of electrons avaliable at the filament to produce x-rays
Step-down tranformer reduces ____ and increases ____
Reduces voltage and increases current.
X-ray tube is made of what two parts?
Cathode and Anode
Negative side of x-ray tube
Cathode
Positive side of x-ray tube
Anode
