final Flashcards
Electrons are accelerated from cathode to anode
by kiliovoltage
The force that holds electrons in orbit around the nucleus of an atom is
binding energy
The K-shell binding energy of Tungsten is approximately
69.5 KeV
Tungsten is the anode target material of choice due to
its ability to conduct heat, high melting point, and high atomic number.
A high speed incident electron (projectile electron) possesses
kinetic energy.
The L-shell binding energy of tungsten is approximately
12.1 KeV.
The number of electrons thermionically emitted from the filament per second is measured as
milliamperes (MA)
The number of electrons actually propelled from cathode to anode is measured as
milliampere-seconds (MAS).
The percentage of electron kinetic energy that is actually converted to x-ray is approximately
1%.
The N-shell binding energy of Tungsten is approximately
0.6 KeV.
The electrical component with the function of emitting electrons is known as the .
cathode
Oil is found in the tube housing to do all of the following
electrically insulate, absorb unusable x-ray, and conduct heat away from the tube.
The focusing cup of the cathode functions through the process of
mutual repulsion.
The area of the anode struck by electrons is known as the
target/focal spot.
The factor that has primary control of beam quality is
KVP
The atomic number of Tungsten is
74
The filament of the cathode is composed primarily of
Tungsten
The process of hardening the x-ray beam is due to
increasing filtration
The force causing the anode to rotate is
magnetic induction
The electrons liberated by thermionic emission and “hovering” within the vacuum tube possess
potential energy
The electrical component with the function of receiving high speed electrons is known as the
anode
The cloud of electrons that have been thermionically emitted is known as
space charge
The amount of total beam filtration must be equivalent to at least
2.5 mm of aluminum
As the atomic number of an element increases its electron binding energy values
Increase
The factor that has primary control of beam quantity is
MAS
As the amount of beam filtration increases
beam quality increases
As the amount of beam filtration increases
beam quantity decreases
As the amount of beam filtration decreases
Beam quality decreases
As the amount of beam filtration decreases
beam quantity increases
The amount of filtration built into the tube and the tube housing is known as
inherent filtration
X-ray beam filtration is measured in its
equivalency to aluminum.
Inherent filtration plus added filtration is known as
total
The average photon strength within the primary beam is known as
beam quality
The majority of x-rays in the primary beam are produced by this interaction
Bremsstrahlung
Thermionic emission-
Emission of electrons through the process of “boiling them off”
Space charge-
Is the overall charge in the x-ray tube after thermionic emission has occurred.
Half value layer-
The ½ value layer is the layer of the x-ray tube that cuts the strength of an x-ray in half.
Characteristic cascade-
The peak in a graph that shows where a characteristic x-ray has formed.
Dual focus-
an x-ray tube with 2 focal spots.
1/3 rule-
If KVP is 90 the majority of the electrons are 30. 1/3 of the strength is where most electrons reside.
What is the advantage of a rotating anode over a stationary anode?
Allows heat to be spread over a larger surface area therefore x-ray tube lasts longer.
X-ray tube holds a vacuum why?
To eliminate any particles so that the high speed electrons can make it from cathode to anode with no interference.
Bremsstrahlung interaction-
occurs when an electron hits the nucleus of a tungsten atom and is slowed down, thus producing an x-ray, (no collision) .
How is the strength of a bremsstrahlung x-ray determined-
the strength of the x-ray is determined by how much the electron slows (how much kinetic energy is lost) the amount lost is the strength of the x-ray.
Characteristic interaction-
a characteristic interaction occurs when an incident electron hits a tungsten electron and knocks it out of orbit an electron from another shell must then hop over to fill the shell thus producing an x-ray.
Strength of a characteristic x-ray-
the strength of an x-ray is determined by which electron was knocked out of orbit and which filled the spot.
Which unit is not a base quantity
volume.
The transfer of heat by the physical contact of solid objects is known as
conduction
The unit of work is the
joule
Acceleration is measured in
meter/second (squared)
The unit of heat is the
calorie
The international unit of calculating x-ray exposure in air is
air kerma.
The transfer of heat by the mixing of molecules in a liquid or gas in known as
convection
X-ray tubes are cooled primarily by heat transfer due to
radiation
The international standard unit of distance is the
meter
The traditional unit for radiant energy absorbed in a medium is known as
rad
The temperature scale that has the freezing point of water as it’s “zero” is
Celsius
The traditional unit for the rate of radioactive decay is
Curie
The temperature scale that has no negative numbers is
Kelvin
The traditional unit for calculating X-ray exposure in air is
Roentgen
The international unit for radiant energy absorbed in a medium is known as
Gray
In the British system of measurements, mass is measured in
Pounds
The unit of force is
Newton
Rad times quality factor (Rad x QF) is the formulas for calculating
REMS
The temperature scale based upon the expansion and contraction of mercury is
Fahrenheit
The sum of an objects matter is
Mass
The kinetic energy of molecules is an expression of
Thermal energy
The traditional unit of power is
Horsepower
The international unit of power is the
Watt
Inertia
An object in motion stays in motion and an object at rest stays at rest unless another force counteracts this
Force
The amount of energy you put into an object to make it do work, force can also be the amount of resistance an object gives back
Energy
The ability to do work
Heat
Movement of molecules creating friction which produces heat
Power
The rate of mechanical energy used to make something happen
To convert kilograms to pounds
Multiply the number of kilograms by 2.2
To convert pounds to kilograms
Divide the number of pounds by 2.2
Velocity is
Distance divided by time
V = d/t
Acceleration is
Speed 2 minus speed 1 over time
A=S2-S1/t (Answer expressed as m/s squared)
Average velocity is
Speed 1 plus speed 2 divided by the number of factors
S1+S2/2
Force is found by
Weight times acceleration
F=w*a = newtons
Newtons Laws
1st - law of inertia - an object in motion stays in motion
2nd - law of force - simply mass times acceleration
3rd - law of action/reaction - for every action there is an equal and opposite reaction
An example of a naturally occurring permanent magnet would be
magnetite.
Matter that is highly attracted to magnets is known as
ferromagnetic.
Magnetic field strength is measured in
tesla.
Electricity creating magnetism is confirmed by
oersted’s law
Matter that is always repelled by magnets is known as
diamagnetic.
Transformers have iron cores in order to
intensify the magnetic field.
Alnico falls into the category of materials known as
ferromagnetic.
The ease with which a material can be magnetized is known as
its permeability.
The factor increased in the secondary side of a step-down transformer is
voltage.
An example of a ferromagnetic material is
iron.
Matter that is always slightly attracted to magnets is known as
paramagnetic.
Reducing the temperature of a conductor to the point that there is virtually no resistance is known as
superconduction.
As the distance between two magnets increases
the force of attraction or repulsion decreases.
A step-up transformer
“steps up” or increases the voltage.
Gadolinium falls into the category of materials known as
paramagnetic.
The ability of a material to stay magnetized is known as its
retenetivity.
An example of a nonmagnetic material is
plastic.
A material that always opposes the flow of electrons is known as
an insulator.
Magnetism creating electricity is confirmed by
Faraday’s law.
As the distance between two magnets decreases the force of attraction or repulsion
increases.
A coil of wire with current flowing through it is known as
a solenoid.
An example of a diamagnetic material is
bismuth.
An electrical circuit with all resistors located on a single wire is known as
a series circuit.
The unit that quantifies electrical power is the
watt.
The unit that quantifies electrical resistance is the
ohm.
The unit that quantifies electrical current flow is the
amp.
The unit that quantifies the force of electron propulsion is the
volt.
Electrification can occur by
contact, friction, and induction.
A material that sometimes allows and sometimes opposes the flow of electrons is known as
a semiconductor.
The electrical component with the function of reconfiguring wattage is the
transformer.
The path over which electrons flow is known as
a circuit.
