cathode
is the cathode positively charged are negatively charged?
negatively charged
the anode acts as a ____ surface for high-voltage electrons from the filament
target
how are x-rays emitted?
isotropically
with the anode heel effect, which side of the x-ray tube should thicker anatomy be placed?
cathode
to use an anode cooling chart, the technical factor must be converted into?
heat units
within the cathode, there is the filament, what is it made of?
tungsten
what are the 2 types of anodes?
stationary and rotating
how much of the tube current interacts with the anode outside the focal spot?
15%
with the anode heel effect, as the target angle decreases, what happens to the intensity?
increases
with housing cooling charts, the tube housing includes ______ to cool the structure, the housing cooling chart is usually not needed
forced air fan
the focusing cup is provided with a low negative potential, equal to the filament, what is the voltage?
6-12 volts
what type of motor does the rotating anode use?
induction
the protective housing is designed to do 3 things, what are they?
control leakage radiation
isolate high voltages
absorb heat & cool the tube
with the line focus principal, a common range of anode angles for a general purpose x-ray tube is approximately?
7-20 degrees
with tube rating charts, for a technique to be considered safe, where should the technique point appear on the chart?
below selected curve
as more electrons build up in the area of the filament, their negative charges begin to oppose the emission of additional electrons, what is this called?
space charge effect
the rotor is connected to the anode by the neck, what is this made of?
molybdenum
what are the 3 requirements for x-ray production? (be specific)
1. source of electrons (tube current)
2. acceleration of electrons (kinetic energy)
3. deceleration of electrons (hitting target, thermionic emission)
the anode heel affect is more noticeable at what kind of SID?
short
what are the 3 ways to dissipate heat in the x-ray tube?
radiation
conduction
convection
increasing the filament current will increase the filament heat and also increase what?
thermionic emission
rotating anodes provide a circular path that will be impacted by the tube current electrons, what is this called?
focal track
what are the other names for the anode target?
TARGET, FOCUS, FOCAL POINT OR FOCAL SPOT
with the line focus principal, the design results in an effective focal spot that appears _____ than the actual focal spot (anode target)
smaller
what is the most common cause of x-ray tube failure?
tungsten vaporization with deposits