X-ray Interactions
What is a Bremsstrahlung interaction?
What is defined as incident electrons interacting w/ the force field of the nucleus of a tungsten atom in the anode?
What is an amplifier that totals the voltage from each cell and divides it by the cells that are activated. When the appropriate voltage for the diagnostic image is reached, it shuts off?
What does the cathode assembly contain?
What is the filament, the focusing cup, and the associated wiring?
What is the formula to measure ESE?
mR1/mR2=SOD2/SID2
What speed do electrons travel? *+100 if you can answer the speed of electrons w/in the tube
What is 3x10^8? *Travel at half the speed of light in the span of 2 cm.
What are the discrete emission spectrum and continuous emission spectrum produced by?
Discrete emission spectrum: produced by characteristic X-ray photons
Continuous emission spectrum: produced by Brems X-ray photons.
What amount of biologic effects are caused by indirect interactions?
What is 2/3 of biological effects that are caused by indirect interactions?
What are grid-biased tubes also known as?
What is grid-pulsed, grid-biased, or grid-controlled?
What is the inverse square law?
What is I1/I2=D2squared/D1squared?
What are the 5 types of generators? *Bonus Question* What are the five types of tube supports?
What is single-phase, multi-phase, high frequency, capacitor discharge, battery-operated generators? *What is overhead suspension system, floor-to-ceiling suspension system, floor suspension system, mobile, and c-arm?*
What is the keV of an average primary beam?
What is 30-40%?
What agency is a regulatory agency responsible for protecting both the public and occupationally exposed individuals from the effect of ionizing radiation?
What is the NRC?
What is the space charge effect? *Bonus Question* What does this limit?
What is the effect that occurs when more and more electrons build up in the area of the filament, causing their negative charges to begin to oppose the emission of additional electrons? This limits X-ray tubes to maximum mA ranges of 1,000-1,200.
What is the formula used to calculate backup time when using AEC?
What is 150 * ____ mAs = _____?
What are the three target interactions?
What is heat production, brems interactions, and characteristic interactions?
When does Compton scattering occur?
What is the occurrence of Compton when an incident photon interacts w/ a loosely bound outer-shell electron, removes the electron from its shell, and then proceeds in a different direction as a scattered photon?
What are the 4 types of dosimeters and what does each contain? *+100 if you can answer how each is read.
OSL: thin layer of aluminum oxide (laser)
Film badge: two pieces of film (film is processed)
TLD: lithium fluoride crystals (heat)
Electronic Personal dosimeter: small fiber on an exposure scale (air w/in small chamber becomes ionized)
What is a line voltage compensator and what is it also known as?
What is also known as line meter or line monitor and is used to measure incoming line voltage, detecting drops or surges, and maintaining 220 volts to the autotransformer.
What is the formula to calculate effective dose?
What is absorbed dose x radiation weighting factor x tissue radiating factor?
What are the recommended minimum total filtration levels for operating kVp?
below 50:0.5 mm al
50-70: 1.5 mm al
Above 70: 2.5 mm al
What is mAs that is directly proportional to IR exposure?
What is the 15% rule that states that increasing kVp by 15% will double IR exposure?
What is the relationship as the distance increases, intensity decreases, which causes a decrease in IR exposure?
*Doubling distance, reduces beam intensity by factor of 4
What is absorbed dose, integral dose, equivalent dose, and effective dose? *Bonus Question* What are their units?
Absorbed dose: measures amount of energy absorbed (Rad/Gy)
Integral dose: total amount of energy imparted to matter (Rad)
Equivalent Dose: product of absorbed dose and radiation weighting (Rem/Sievert)
Effective Dose: sum of equiv. doses of specific tissues.
What are the definitions of phase, pulse, and frequency?
What is phase: # of wave cycles in a circuit, pulse: # of voltages per wave cycle, frequency: # of pulses in a wave cycle?
What is the formula to calculate heat units?
What is kVp x mA x time x rectification constant?
What is attenuation?
What is the reduction in # of X-ray photons in the beam, and subsequent loss of energy, as the beam passes through matter?