X-ray Tube Flashcards
Actual focal spot
the area of the anode surface which receives the beam of electrons from the cathode.
Anode
the component of the x-ray tube where x-rays are produced
Cathode
the negatively charged side of x-ray tube circuit
Dual-focus
cathode focused to provide two contiguous line-focus focal spots each of 1 millimeter width
anode assembly
anode, stator, rotor
what are the two types of anodes?
stationary anodes, rotating anodes
why is tungsten the best metal for the x-ray machine?
- high atomic #
- high melting point
- heat-conducting ability
what is the metal tungsten’s atomic #?
74
what is the same charge effect?
as more electrons build up in the area of the filament, negative charges oppose emission of additional charges
what is the line-focus principle
it is used to reduce the effective area of the focal point
what is the anode heel effect?
the radiation intensity is greater on the cathode side.
what is off-focus radiation
it comprises photons that were not produced at the focal point
what conditions must exist for x-rays to be produced?
- source of electrons
- appropriate target
- high voltage
- vaccuum
what is thermionic emission?
the emission of electrons from a heated source
what is the function of the focusing cup?
narrows the thermonic cloud as its driven toward the anode
what does the cathode assembly consist of
filament, focusing cup and wiring
where is the stator located?
outside of the vacuum of the envelope
where is the rotor located?
inside the stator and inside the envelope
what is the function of the envelope?
to maintain the vacuum between the cathode and anode
What units are used in Radiography?
SI units
what is the unit name/symbol for absorbed dose?
Gray, Gy
what is the unit name/symbol for electric potential?
volt, v
what is the unit name/symbol for dose equivalent?
Sievert, Sv
what is the unit name/symbol for exposure?
Coulomb/kg, C/kg
what is the unit name/symbol for frequency?
Hertz, Hz
what is the unit name/symbol for magnetic flux density?
Tesla, T
what is the unit name/symbol for power?
Watt, W
what is the unit name/symbol for radioactivity?
Bequerel, Bq
what is the unit name/symbol for energy?
Joule, J
what does Kv stand for, and how many volts are there in one Kv?
power, 10,000
what does mA stand for, and how many volts are in one?
quantity, 1/1000 ampere
what is matter?
a mixture of substances
what can break molecules?
x-rays
T/F: electrons can be divided
False
