click below
click below
Normal Size Small Size show me how
slcc rads 1030
Question | Answer |
---|---|
The cathode is on the ___________ side | neg |
Name 2 parts of the cathode assembly | filament and focusing cup |
The filament is made out of_____ | tungsten |
Describe the focusing cup | Shallow depression in the cathode designed to hold the filament |
The anode is ______ | positive |
3 functions of the anode | Target area, conduct high voltage, primary thermal conductor |
Why does the anode rotate? | The make a bigger target |
What % of target interaction produces x-rays? | less than 1% |
In Bremsstrahlung interactions, what part of the atom does the incident electron interact with? | Force field |
In Bremsstrahlung interactions, what happens when teh incident electron gets close to the nucleus? | + attracts the -. Electron slows down and brakes. The electron course is diverted. Energy lost by the braking = x-ray. |
Bremsstrahlung photon energy is exactly the difference between the _____ and _______ energy of the electron. | Entering and exiting |
True or false- Photons from Bremsstahlung interactions can have a wide variety of energies, ranging to a minimal amount to peak KV. | False |
In Characteristic interactions, what part of the atom does teh incident electron interact with. | inner shell electron |
What happens to the incident electron after a Characteristis interaction? | It knocks the inner electron shell out of orbit. Ionizes the atom . It makes the atom change course to a different direction and creates an unstable atom. |
How are x-rays created during Characteristic interactions? | An electron from another shell will drop into the hole. An electron from a higher to lower energy state results in energy difference between 2 shells=x-ray |
Characteristic photon energyis exactly the difference between the binding energy of the ____and _______ shells between which the electron dropped | outer and inner |
What is the Characteristic cascade | shells drop form an outer to inner shell until only the outermost shell is missing an electron |
Define electrons | - charge, orbits the nucleus |
Define protons | + charge, helps make up the nucleus |
define neutrons | no charge |
What is the atomic # | # of protons |
How are elements listed on the periodic table | by atomic number, ascending order |
Describe an isotope | lose or gain of an neutron |
Define atomic mass | # of protons and neutrons |
Name 2 types of mechanical energy | Kinetic and potential |
As orbital electrons move away form the nucleus, what happens to the binding energy? | Decreases and becomes unstable |
Name the different forms of energy | Chemical, heat, nuclear, electromagnetic,electrical, mechanical |
Name the common properties of electromagnetic energy radioation | broad velocity |
Name the ways x-rays travel | in s stright line, needs no medium |
What is the wave equation? | v=f x wl |
List the 12 properties of x-ray | Florese, highly penetrable, electrally neutral, release heat, travels in a stright line, travels at the speed of light, ionizes matter, can't be focused, photographic film, biological change, scatter, wide variety if energy and wavelengths. |
Described how mAs relates to tube current and number of electrons. | It measures the tube current. It's directly proportional. If you increase yours mAs, you increase the # of electrons |
Define radiolgraphic density. | the degree of blackening |
When mAs increases, what happens to exposure? Radiogrphic density? | Exposure is longer (more), it will have greater density. |
When mAs is decreased, what happens to exposure? Radiographic density? | Less exposure, Light density (lighter) |
WHat is the reciprocity law? | If ma or time is doubled, mAs is doubled |
Describe penetrablility and how it relates to the energy of photons. | Increase electron energy results in x-ray photon with greater penetrablility |
Describe the relationship of kVp to density | the more kVp the more density (darker) |
Changes in kVp affect what? | Contrast, quality and quantity |
Effects of changes in kVp are greater in which range of kVp- high or low? | low |
Describe how changes in distance effect x-ray intesity and density. | More intensity @ decreased distance. Inversely proportional |
List the prime factors | mAs, kVp and distance |
What other terms are used to signify quantity in regards to x-ray photons on the useful beam? | x-ray output, intensity and exposure |
List the factors the directly affect x-ray quality and quantity. | mAs, kVp distance and filtration |
What happens to the number of electrons when mAs is doubled? Halved? | electrons double |
The relationship between the number of electrons when mA is doubled or halved is _____ proportional | directly |
X-ray quantity is primarily conrolled by____? | mAs |
X-ray quantity is equal to the product of ____ and ____ | mA and time |
Density is primarily controlled by______ | mAs |
The relationship between mAs and exposure is ________ proportional | directly |
What happens to electrons when kVp is increased? Decreased? | gain more energy, lose more energy |
When kVp is doubled, what happens to the quantity of the x-ray photons? | more penetrating |
Kvp is the primary controller of_____ | contrast |
What is the 15% rule. | If you increase kvp 15% you decrease your mA by 1/2. If you decrease you kvp 15% you double your mA |
Adjustment to kVp should only be used to control _______ | contrast |
Relationship of x-ray quantity to distance is known as the _________ law. | Inverse square law |
Density maintence formula is what type of law? | Direct square law |
What is teh formula for mAs? | mA x time (s) |
What is the formula to find mA? | mAs/s |
What is the formula to find time? | mAs/mA |
What is the inverse square law? | I1/I2=(d2)2/(d1)2 |
What is the density maitenance formula? | mAs1/mAs2=(D1)2/(D2)2 |
Define quantity | how much x0ray is being used |
Name 4 factors that DIRECTLY affect x-ray quantity (amount) | kVp, filtration, distance and mAs |
The factors that directly affect x-ray quality | kVp and fitlraion |