Quiz 1 Flashcards
(22 cards)
the term for the monoenergetic beam which matches the attenuation of a polyenergetic beam is called the A. most probable energy B. effective energy C. average energy D. mean energy
B. effective energy
the energy measurement most useful for x-ray beams between 50 keV and 200 keV is A. most probable enegy B. peak energy C. average energy D. half value layer
D. half value layer
the average energy fluence of a photon beam is the A. effective energy B. most probable energy C. peak energy D. mean energy
D. mean energy
for monoenergetic beams A. HVL1 is dependent on HVL2 B. HVL1 is greater than HVL2 C. HVL1 is less than HVL2 D. HVL1 is equal to HVL2
D. HVL1 is equal to HVL2
T/F: for polyenergetic beams HVL1 is greater than HVL2
false
which of the following is not a reason for measuring the quality of an x-ray beam?
A. to determine the ionization chamber response
B. to set up the dosimetry for planning
C. to determine the appropriate room shielding
D. to determine the valibration frequency
D. to determine the valibration frequency
the quality of the radiation beam is measure of the photon A. energy B. output C. flux D. all of the answers are correct
A. energy
which measurement would not be used for describing the enrgy of a megavoltage photon beam? A. HVL B. TPR at 20cn/TPR at 10 cm C. depth of maximum dose D. PDD at 10 cm
A. HVL
T/F: bremsstrahlung is an example of elastic collision
false
bragg-gray theory states the ionization produced in a gas-filled vacity placed in a medium is realted to the \_\_\_\_\_\_ absorbed in the surrounding medium if the cavity doesn't alter the \_\_\_\_\_ or distribution of the electron that would exist if there were no cavity. A. charge, energy B. fluence, charge C. energy, number D. electrons, energy
C. energy, number
which of the following would be appropriate to measure beam quality of a megavoltage electron beam? A. depth where PDD is 50% B. HVL C. PDD at 10 cm D. TPR at 20 cm and 10 cm
A. depth where PDD is 50%
which of the following is trueof the f-factor?
A. it is also called the R to rad factor
B. it is independent of the energy of the photon
C. it can be used for all types of radiation
D. it is independent of the medium measured
A. it is also called the R to rad factor
the historical equivalent of 10 cGy is A. 1000 millirads B. 10 rads C. 100 rads D. none of the answers are correct
B. 10 rads
in the equation for KERMA, K=(∆Etr/∆m), for phtons the quantity Etr is the sum of all the initial kinetic energies of the
A. incident photons per unit mass
B. incident photons
C. charged particles created by uncharged particles per unit mass
D. charged particles created by uncharged radiaiton
D. charged particles created by uncharged radiaiton
absorbed dose is energy \_\_\_\_\_\_\_\_ matter and KERMA is energy \_\_\_\_\_\_ matter A. created by, absorbed by B. transferred to, released by C. absorbed by, released to D. released by, created by
C. absorbed by, released to
beyond electronic equilibrium which of the following is true
A. photon fluence increases
B. the value of the absorbed dose is greater than the value of the KERMA
C. the absorbed dose and KERMA decrease at the same rate
D. none of the answers are correct
C. the absorbed dose and KERMA decrease at the same rate
in parallel plate chamber the point of measurement when measuring electron is
A. on the enterance window of the detector
B. on the external surface of the beam side of the chamber
C. the center of the plates
D. on the central electrode
A. on the enterance window of the detector
primary phton and electron calibrations are measured in what type of phantom? A. water B. all of the answers are correct C. solid water D. PMMA
A. water
the measurement technique which measures the amount of ferric ions created for ferrous ions is called A. ferric ion dosimeter B. fricke dosimeter C. thermoluminescent dosimeter D. wheatstone dosimeter
B. fricke dosimeter
which radiation detector releases stored energy when heat is applied to the detector? A. OSLD B. diode C. NKD D. TLD
D. TLD
which is not an advantage of OSLD measurement of radiation? A. minimal energy dependence B. immediate readout of dose C. non-destructive readout D. minimal fading of signal
B. immediate readout of dose
which is true about radiochromic film for dose measurement? A. insensitive to visible light B. large dose range C. high spatial resoluation D. low energy dependence E. all of the answers are correct
E. all of the answers are correct
