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.
The electrical component that allows current flow in only one direction is the
rectifier.
The factor decreased in the secondary side of a step-down transformer is
voltage.
Electrons flowing in only one constant direction is known as
direct current.
An object with too many or too few electrons is said to be
electrified.
The flow of charged particles along a conductor is known as
electric current.
The flow of 6.3 x 10^18 electrons per second along a conductor is known as
1 ampere.
The formula for computing electric power is
V x I
The number of electrons in motion is known as
amperage.
The method of electrification that is most important to x-ray production is
induction.
A material that readily allows the flow of electrons is known as a
conductor.
The electrical component that functions as a variable resistor is the
rheostat.
All of the following terms are synonymous :
voltage, potential difference, and electromotive force.
The study of stationary charges is known as
electrostatics.
The study of charges in motion is known as
electrodynamics.
Direct current:
electrons flowing in one constant direction.
Alternating current:
electrons flowing in two different directions at different intervals.
Oersted’s Law:
electricity can create magnetism.
Faraday’s Law:
magnetism can create electricity.
What are the advantages of an electromagnet versus a permanent magnet?
Electromagnets have an on/off switch and the strength of the magnet can be controlled.
The unit that quantifies electrical power is the
watt.
The number of electrons in motion is known as
amperage.
A half wave rectified voltage waveform utilizes
60 pulses per second.
The unit that quantifies the force of electron propulsion is the
volt.
The number of x-rays in the polyenergetic primary beam is expressed as
MAS.
A step-up transformer
steps up the voltage.
An autotransformer functions through the process of
self-induction.
With half-wave rectification and a 1/4th of a second exposure there will be
15 pulses.
The electrical component with the function of reconfiguring wattage is the
transformer.
Within the high voltage generator section is found all of the following components:
rectifiers, step-up transformer, and step-down transformer.
The electrical component that allows current flow in only one direction is the
rectifier.
The factor increased in the secondary side of a step-down transformer is
amperage.
The least efficient voltage waveform for x-ray production is
half-wave rectification.
A full-wave rectified voltage waveform utilizes
120 pulses per second.
The number of electrons thermionically emitted per second is measured as
milliamperes (MA).
Transformers have iron cores in order to
intensify the magnetic field.
The voltage waveform with approximately 14% voltage ripple is
3 phase, 6 pulse.
The unit that quantifies electrical resistance is the
Ohm.
The most efficient voltage waveform for x-ray production is
high frequency.
The voltage waveform with 100% voltage ripple is
full-wave rectification.
The electrical component that functions as a variable resistor is the
rheostat.
The factor increased in the secondary side of a step-up transformer is
voltage.
A transformer with a fixed ratio of 1000:1 is known as
high voltage transformer.
Within the control console section is found all of the following components:
Line compensator, KVP selector, and MA selector.
The strength of the x-rays in the polyenergetic primary beam is expressed as
KVP.
The number of cycles per second in a wave is known as
frequency.
A 3 phase, 6 pulse voltage waveform utilizes
360 pulses per second.
Self-rectification is also known as
half-wave rectification.
A fixed ratio transformer functions through the process of
mutual induction.
Most x-ray machines are designed to operate on an incoming voltage of
220 volts
Transformers that have variable ratios are known as
autotransformers.
The voltage waveform that delivers the lowest x-ray exposure to the patient is
high frequency.
A transformer with a fixed ration of 1:3 is known as
step-down transformer.
With full-wave rectification and a 1/10th of a second exposure there will be
12 pulses.
3 things for x-ray production:
Source of free electrons
Acceleration of electrons
Abrupt halting of electrons.
Why does the x-ray circuit require both AC and DC?
X-ray requires AC and DC because it needs the different currents to properly obtain the volts and amps it needs to operate.
Rectifier-
a device that converts AC to DC
Line compensator-
controls the amount of incoming electricity so that the machine does not receive too much or too little.
Voltage ripple-
the amount of voltage that is not properly utilized and is left over.
V1/V2= T1/T2
V1/V2= T1/T2
The periodic table presents
the elements in the order of atomic number.
The K-shell binding energy of Tungsten is
approximately 69.5 KeV.
The modern definition of atomic structure is credited to
Bohr.
The force that holds electrons in orbit is
binding energy.
Atoms having the same atomic number but different atomic masses are called
isotopes.
The maximum number of electrons which may be in an atom’s M shell is
(2*3^2) 18
The positively charged particles found within the nucleus of atoms are known as
protons.
The maximum number of electrons which may be in an atom’s K shell is
(2*1^2) 2
The negatively charged particles that orbit the nucleus of atoms are known as
electrons.
The maximum number of electrons which may be in an atom’s N shell is
(2*4^2) 32
The number of protons plus neutrons within an atoms nucleus is known as the
atomic mass.
Of the following particles the one that possesses the greatest mass is the
neutron.
The M-shell binding energy of tungsten is approximately
2.8 KeV.
The atomic number of Lead (Pb) is
82.
The number of protons within an atom’s nucleus is known as the
atomic number.
As the distance from the nucleus decreases electron binding energy values
increase.
As the atomic number of an element increases its electron binding energy values
increase.
The maximum number of electrons which may be in an atom’s L shell is
(2*2^2) 8
The arrangement of electrons around the nucleus of an atom is known as
rings, shells, or orbits.
As the distance from the nucleus increases electron binding energy values
decrease.
As the atomic number of an element decreases its electron binding energy values
decrease.
An atom’s nucleus emitting energy and/or particles in an effort to stabilize is called
radioactivity.
The sum of an object’s matter is an expression of
the object’s mass.
The periodic table of elements is credited to
Mendeleev.
The L-shell binding energy of Tungsten is approximately
12.1 KeV.
The N-shell binding energy of Tungsten is approximately
0.6 KeV.
The atomic number of Tungsten is
74.
We know that in a stable atom, atomic number has the symbol “Z” and equals
number of orbital electrons.
A single proton has the same mass as this many electrons
1836.
When 2 or more atoms share a common outer shell electron orbit we have a
covalent bond.
When atoms are bound together due to the transfer of an outer shell electron we have
ionic bond.
The energy possessed by a single electron is
0.51 MeV.
What does an element’s periodic table “group” classification tells us about the atom-
The group classification tells us how many electrons are in the outermost orbital ring.
What an element’s periodic table “period” classification tells us about that atom
the period classification tells us how many valences the element has.
The three major sub atomic particles along with their magnetic charges are –
proton:positive neutron:neutral electron:negative.
The two causes of electron binding energy variations are
number of protons in the nucleus, more protons means higher binding energy. Distance of the electron from the nucleus more distance is less binding energy.
Nucleon-
the number of protons and neutrons in the nucleus.
Ionization-
an unstable atom that is throwing away electrons in an attempt to become stable.
Ion-
an electrically charged atom or group of atoms formed by the loss or gain of one or more electrons
Bohr atom-
the atom is like a solar system and is mostly empty space.
Describe the properties of energy-based ionizing radiation-
energy based ionizing radiation is x-ray, where we are “forcing” the electrons where we want them to be and forcing them to be unstable by using heat and electricity to make this happen.
Properties of matter based ionizing radiation-
this is like uranium or the solid material used in nuclear medicine that the radiation is coming from a steady source and not being artificially produced.
A high speed incident electron possesses
kinetic energy.
The filament of an x-ray tube’s cathode is composed primarily of
tungsten.
X-rays escaping the tube housing at a point other than the tube window are known as
leakage radiation.
The force that causes a rotating anode to rotate is
magnetic induction.
The cloud of electrons that have been thermionically emitted is known as
space charge.
The electrons liberated by thermionic emission and hovering just off of the filament possess
potential energy.
The electrical component with the function of receiving high speed electrons is known as
the anode.
The number of electrons thermionically emitted from the filament is measured as
milliamperes (MA)
The area of the anode struck by electrons is known as the
target.
The focusing cup of the cathode functions through the process of
mutual repulsion.
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 electrical component with the function of emitting electrons is known as the
cathode.
The percentage of electron kinetic energy actually converted to x-ray is
approximately 1%.
The number of electrons actually propelled from cathode to anode is measured as
milliampere-seconds (MAS)
The anode of an x-ray tube is composed of all of the following:
Tungsten, molybdenum, and iron.
The standard anode angle is 12 degrees.
Tungsten, molybdenum, and iron.
Tungsten is the anode target material of choice due to its
high atomic number.
The 3 things required for x-ray production as well as what provides them:
Source of free electrons- cathode
Acceleration of electrons- cathode filament
Abrupt halting of electrons- anode
Anode heel effect-
the phenomenon of more x-rays being emitted from the cathode side of the tube.
Advantages of rotating anode over stationary anode-
Heat is more spread out in a rotating anode.
An atom’s nucleus emitting energy and/or particles in an effort to stabilize is called
radioactivity.
The number of cycles per second in a sine wave is known as
frequency.
The height of a sine wave is known as
amplitude.
The distance from one point to a corresponding point on a sine wave is known as
wavelength.
A synonymous term for photon is
quantum.
Frequency is measured in
hertz.
Atoms having the same atomic number but different atomic masses are called
isotopes.
The characteristic that is not a property of a photon is
negative charge.
The speed of light is approximately
186,400 miles per second.
As wavelength increases the frequency of a wave
decreases.
All of the following originate in the nucleus of an atom:
alpha, gamma, and beta
The type of ionizing radiation that causes the most tissue damage per interaction is
alpha.
As the wavelength of a given type of EMR decreases its energy
increases.
The wave characteristic represented by the lower-case letter (c) is
Velocity.
As the wavelength of a given type of EMR increases its velocity
remains the same.
Wavelength is measured in
meters.
The amount of time required for radioactive material to decrease to ½ its original intensity is
half-life.
As the frequency of a given type of EMR decreases its velocity
remains the same.
A radioactive material has a half-life of 2 years, we have 200 curies today, and in 6 years we will have
25 curies.
All of the following are capable of ionizing matter:
gamma, x-ray, and alpha particles.
The wave characteristic represented by the Greek letter lambda is
wavelength.
As the distance from the source of ionizing radiation increases
the exposure intensity decreases.
The range of visible light wavelengths is
approximately 400-700 nm.
When light energy is absorbed by matter its energy is
transformed into thermal energy.
The partial absorption and partial transmission of visible light (or x-ray) is known as
attenuation.
Cellular phone transmissions/ communications fall into the category of EMR known as
microwave.
As the frequency of a given type of EMR increases
its energy increases.
The interaction most responsible for the production of scatter is
Compton.
As wavelength decreases the frequency
increases.
All of the following are examples of matter-based ionizing radiation:
alpha, neutron, and beta.
As the wavelength of a given type of EMR increases
its energy decreases.
The interaction most responsible for the absorption of x-ray energy by matter is
photoelectric.
As the frequency of a given type of EMR decreases
its energy decreases.
As the distance from the source of ionizing radiation decreases
the exposure intensity increases.
The physicist credited with the formula equating EMR wave characteristics to EMR energy is
Planck.
I1/I2= D2 (squared)/D1 (squared).
I1/I2= D2 (squared)/D1 (squared).
Relationship between a type or EMR and the object the EMR interacts with:
microwaves interact with water molecules so the wavelength of microwaves are comparable to the size of a water molecule.
Photon-
smallest amount of any type of EMR.
Radiopaque-
x-ray cannot travel through it.
wave equation-
velocity= frequency x wavelength
Attenuation-
partial absorption and partial transmission of x-ray as it passes through a material.
Electromagnetic energy-
energy in transit through space.
Properties of energy-based ionizing radiation-
no mass, no charge, wavelength movement, and pure energy.
Properties of matter based ionizing radiation-
has mass, has charge, straight line movement.
Describe the waveform of an x-ray-
x-ray waveform is a very short wavelength with high amplitude and high frequency.
How does increasing distance decrease x-ray intensity and exposure to humans? I
nverse square law, because the further away you get, more x-rays diverge, are absorbed elsewhere and exposure goes down.
Ionizing radiation-
high energy that has the ability to disrupt anatomic structure usually by knocking electrons out of orbit.
