X-ray Tube
What is required of a metal target in an x-ray tube?
1)Ability to conduct heat 2) High atomic number 3)High melting point
How fast do high speed anodes rotate?
10,000RPM
How many kilovolts is equal to 75,000 volts?
75kV
What is the area of the x-ray target called that is struck by electrons?
Actual focal spot
In what unit is filament current measured?
Amperage
As kilovoltage is applied, the electrons are accelerated toward which part of the x-ray tube?
Anode
What types of primary radiation is produced when the x-ray tube boltage is below 70?
Bremsstrahlung
What is the negative terminal x-ray tube?
Cathode
Which part of the x-ray tube has the filament wires and focusing cup?
Cathode
Electrons travel in an x-ray tube from ___ to ___.
Cathode, Anode
What is the purpose of the anode in an x-ray tube?
Decelerates electrons
What are the x-ray tubes called that have 2 filament wires?
Dual focus tubes
Which is the smallest? -Space charge -Actual focal spot -Effective focal spot -Target
Effective Focal Spot
Which is not related to the other? -Rotor -Target -Filament -Tungsten Disk
Filament
Which parts make up the cathode end of the x-ray tube?
Filament and focusing cup
The formula, mA x kVp x time(s) is for what?
Finding heat units
What is used to focus the electron stream toward the target of the anode?
Focusing cup
What is the purpose of a window in an x-ray tube?
For the emmision of x-rays
When electrons strike the target of an x-ray tube, most of their energy is converted to what?
Heat
What determines the quantity of electrons that will be accelerated across the x-ray tube?
Heating of the filament
Which kVp and mAs combination produce the least load on an x-ray tube?
High kVp, low mAs
As the x-ray tube gets older, what happens to the temperature of the filament?
Increases
What type of motor drives the rotating anode?
Induction
Which of the following is filtration that is manufactured into the x-ray tube?
Inherent Filtration
Why is an x-ray tube immersed in oil?
Insulation
What increases the penetrating power of the x-ray tube?
Kilovoltage
When electrons strike the anode of an x-ray tube, how much of their energy is converted to x-rays?
Less than 1%
What causes the pitting of the x-ray tube target?
Moderate overloading of the tube
If used properly, will an x-ray tube last forever?
No, the filament wire will break
What is the definition of off focus radiation?
Photons that are not produced at the focal spot
The small craters in the target of a used anode of an x-ray tube are known as what?
Pitting
During an exposure, what electrical charge is placed on the anode?
Positive
Why is that x-ray tube encased in a lead housing?
Prevent leakage radiation
What is NOT needed to produce x-rays?
Rotating anode
What would NOT be found on the control panel?
Rotor button
According to the line focus principle, the effective focal spot is ___ than the actual focal spot.
Smaller
During thermoniac emission a cloud of electrons surround the filament. What is the electron cloud called?
Space charge
What effect will increasing the kVp have on the production of x-rays?
Their energy will increase
What is the process of "boiling off" electrons called?
Thermionic Emission
Why is an x-ray tube made of Pyrex glass?
To better withstand heat
As electrons are accelerated across the x-ray tube, they are referred to as what?
Tube current
The filament wires in radiographic tubes are made from what metal?
Tungsten
The target of an x-ray tube is made of what metal?
Tungsten
In a modern, rotating anode x-ray tube, what coats the tungsten disk?
Tungsten rhenium alloy
When will a space charge be present in the x-ray tube?
Whenever the rotor engaged
What causes most x-ray failures?
excessive heat