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Question Answer
how many diodes are used in half wave rectification 2
how many diodes are used in full wave rectification 4
what do transformers control/change? voltage
what type of transformer has a higher voltage on the secondary side than the primary side step up
what type of transformer is a step up transformer high voltage
what type of transformer is the first transformer in the operating console of the imaging system and has a single winding autotransformer
autotransformers work off of what type of induction self induction
the autotransformer supplies a precise voltage to the ____ and the _____ filament and high voltage circuit
what type of transformer is used in the high voltage circuit step up
what type of transformer is used in the filament circuit step down
what type of transformer has a higher voltage on the primary side than the secondary side step down
transformes operate on what type of current alternating
what is the emission of electrons from a heated surface, HAPPENS AT THE FILAMENT thermionic emission
what area is where the electrons sit beyond the filament to prepare to be focused by the focusing cup space charge
what effect is when the cloud of electrons makes it hard for subsequent electrons to be emitted because of electrostatic repulsion, happens when negative charge builds up and pushes back which doesn't allow electrons to enter space charge space charge effect
thermionic emission at ____ kvp and ____ mA can be space charge limited low, high
what phenomenon is when tube current rises with increasing voltage to a max value (w/ any given filament current) and an increase in kV will not result in a higher mA because all of the available electrons have been used saturation current
when an X-ray tube is operated at the saturation current it is said to be ____ emission limited
what happens when X-rays are produced outside of the focal spot which extends the size of the focal spot, increases skin dose, and reduces image contrast extrafocal radiation
how can extra focal radiation be fixed by designing a fixed diaphragm in the tube housing near the window of the X-ray tube or putting a metal enclosure around the tube
does using a grid reduce off focus radiation no
why do we use filtration to absorb low energy X-rays and keep them from escaping tube and lower patient does
what does kV control penetrating power of X-ray beam QUALITY
what does mAs control how many X-ray photons are available in the beam QUANTITY
as voltage increases, amperage/current ______ and vise versa decreases
what is the inverse square law I1/I2=D2^2/D1^2
an xray tube voltage with less ripple has ____ radiation quantity and quality that result from more constant voltage supplied to the X-ray tube greater
why is the radiation quantity greater in an X-ray tube with less ripple because the efficiency of X-ray production is higher when the tube voltage is high
why is the radiation quality greater in an X-ray tube with less ripple because fewer low energy projectile electrons pass from the cathode to the anode to produce low energy X-rays which makes the average X-ray energy greater
what type of exposure timer has a motor that drives a shaft at 60 revolutions per second, the minimum exposure time possible is 1/60 s, and cannot be used for serial exposures because they must be reset after each exposure synchronous
what are the 4 types of timers synchronous, electronic, mAs, and AEC
what type of timer is the most accurate and consist of circuitry based on the time required to charge a capacitor through a variable resistance, allow a wide range of time intervals, can be used for rapid serial exposures, and often used in IR electronic
what type of timer is used on portables, monitors the product of mA and exposure time and terminates the exposure when the desired mAs value is attained, usually provides the highest safe tube current for the shortest exposure for any mAs selected mAs
what type of timer measures the quantity of radiation that reaches the IR, it automatically terminates when the IR has received the required radiation intensity AEC timer
single phase half wave contains how many diodes 0, 1, or 2
single phase half wave produces how many pulses per second 60
single phase half wave produces how much voltage ripple 100%
single phase half wave produces a ____ exposure time and the ____ quality/quantity of the X-ray beam longest, lowest
single phase full wave contains a minimum of how many diodes 4
single phase full wave produces how many pulses per second 120
single phase full wave produces how much voltage ripple 100%
are X-rays produced at or near zero of diagnostic value no
what type of waveform is 3 waves out of sync with each other three phase
in full rectification, three phase 6 pulse produces how many pulses per second 360
in full rectification, three phase 12 pulse produces how many pulses per second 720
single phase half wave waste how much power 1/2
voltage ripple is greatly improved with single phase or three phase? three phase
which is more effective – three phase 12 pulse or three phase 6 pulse three phase 12 pulse (4%)three phase 6 pulse only 13%
what is another name for diode rectifiers
what electronic device (vacuum like) controls the direction of the flow of electrons diode
the X-ray tube itself is a very large ____ diode
how much is a transformer in a X-ray tube transforming voltage 500-1000 times
what is how much the voltage waveform varies across the time of exposure voltage ripple
the mA meter works off of ____ current direct
the mA meter is on the ____ voltage side of the X-ray circuit but it is _____ voltage high, low
what 2 things allow the mA meter to be low voltage and on the operating console the ground and because it;s at the zero point
once you pass the step up transformer voltages turn into ______ kilovoltages
mA selector chosen determines small or large _____ focal spot
the filament circuit is responsible for providing the ___ that will be used in the tube current electrons
what is the primary/low voltage side of the circuit before the step up and step down transformers
what is the secondary/high voltage side of the circuit after the step up and step down trasnformers
the bottom portion of the X-ray circuit is the filament circuit
AEC timers use a ____ chamber ionization
the standard frequency in the US is ______ 60
three phase rectification is 3 separate ways that are connected using delta star or y connectors
how much are the three waves in a three phase waveform out of sync with each other 120 degrees
in high frequency, 60 Hz is converted to ______-______ Hz then transformed to higher voltage 500, 25000
high frequency has nearly _____ voltage constant
the voltage ripple in high frequency is ______% <1
high frequency produced the ______ quantity and quality of the X-ray beam highest/best
power is measured in kiloWatts
what is the power rating formula current x potential (voltage)/1000 = mA x kVp/1000
if you have a single phase generator you multiply the power rating formula by _____ .7
what are the external parts of the X-ray tube support system (floor to ceiling, ceiling, c arm), protective housing, and enclosure (glass/metal)
what are the internal parts of the X-ray tube cathode (filament/focusing cup) and anode (rotating/stationary)
what is the most common type of enclosure used in todays X-ray tubes metal
how often do high capacity X-rays tubes rotate 10,000 RPMs
how often do diagnostic X-ray tubes rotate 35000-5000 RPMs
what causes the anode to spin producing current through the stators
where are X-rays created at the target
how much of the electron beam is converted to heat rather than xrays 99%
what is the purpose of the line focus principle it allow us to angle the target surface so that when it gets struck at certain angles it can widen the actual focal spot for heating while still maintaining a small effective focal spot
as the anode angle increases the effective focal spot ______ and vise versa increases
the ____ focal spot will always be smaller than the ____ focal spot effective, actual
what is the difference between the actual focal spot and the effective focal spot effective – area projected into patient and IRactual – where electrons interact with the target
what does the line focus principle improve improves spatial resolution and heat capacity
why is the anode heel effect important the weaker intensity of the beam is on the anode side and can be used to our advantage in some exams like fat, chests, and abdomens that vary in thickness
the smaller the anode angle, the ______ the anode heel effect is larger
what is the negative side of the tube cathode
what is the positive side of the tube anode
what is the biggest problem as far as damaging the cathode and anode using improper technique which can cause excessive heat loads on tubes, can cause filaments to bust and anodes to start pitting
what is the most common cause of tube failures tube arcing from tungsten
what do you use rating charts for to look at what the maximum exposure time is that we can use
what is a cooling chart used for to tell us how much time we have to let the tube cool before we can add more heat units to it
how do you figure out heat units in single phase kv x mA x s
how do you figure out heat units in three phase 1.4 x kv x mA x s
X-rays are operated at voltages of 30-150 kvp
X-rays are operated at currents of 100-1200 mA
what are the 3 main parts of the X-ray imaging system tube, operating console, high voltage generator
the operating console is set at a _____ voltage low
what triggers the focal spot selection mA selection
the filament uses ___-____ amps 3-6
what is a diagnostic tubes turn ratio range between 500:1 and 1000:1
electrons only flow in the _____ half of a circuit when dealing with wave rectification positive
the best quality X-rays are produced at the ____ of a wave peak
the difference in waveform as you go from primary to secondary side is the _____ increases as you go from primary to secondary amplitude
leakage radiation has to be less than _____ mR/hour from the protective housing 100
what part of the X-ray tube controls leakage and scatter radiation while isolating the high voltages and providing a means to cool the tube protective housing
what are the 2 electrodes in the X-ray tube anode and cathode
why is the glass/metal enclosure usually made of pyrex bc of high high capacity
what part of the X-ray tube contains the vacuum the enclosure
the improved metal enclosures maintain a constant ______ between the electrons of the tube and the enclosure electric potential
what can you add to tungsten to keep it from breaking Thorium
what is tungstens boiling point 3410 degrees
xray tubes are dual focus meaning they have ____ focal spots 2
what are the 3 functions of the anode electrical conductor, mechanical support for target, thermal dissipater
what is the anode made of tungsten, molybdenum, graphite
tungsten has a ___ atomic number, ______ thermal conductivity, and a _____ melting point high, good, high

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