RAPHEX EXAM QUESTIONS WITH SCORED A+ SOLUTIONS/NEWEST UPD
Study online at https://quizlet.com/_h77htl
1. In the equation for radioactive decay, lambda repre- the fraction of atoms that de-
sents _________ cay per unit time
2. Purpose of rounded leaf ends for MLCs keep the geometric penum-
bra relatively constant for dif-
ferent leaf positions
3. Neutron contamination is greatest in a _______ beam c. 18 MV photon
a. 6 MV photon remember neutrons are pro-
b. 10 MV photon duced through photon in-
c. 18 MV photon teractions, begin happening
d. 6 MeV electron above 10 MV photons
e. 20 MeV electron
4. Loss of charged particle equilibrium is greatest in < 5x5; >= 15 MV
lung radiotherapy for field sizes _______ cm2 and pho- effect is greater for higher
ton energies _______ MV photon energies since the
average energy of the sec-
ondary electrons is greater.
effect is greater for small
field sizes, harder to main-
tain CPE in small space
5. What is the relationship between HVL1 and HVL2 for HVL1 < HVL2 always
a polyenergetic kV photon beam As a polyenergetic kV pho-
ton beam traverses a ma-
terial, lower-energy photons
will be preferentially attenu-
ated. Therefore, as the beam
travels farther into a mater-
ial, it will become hardened
and its average energy will
, RAPHEX EXAM QUESTIONS WITH SCORED A+ SOLUTIONS/NEWEST UPD
Study online at https://quizlet.com/_h77htl
increase. Therefore, the HVL
will increase as well.
6. Compton scattering angles for minimum and maxi- MAX ENERGY TRANSFER -->
mum energy transference electron scattered 0 degrees
(forward) and the photon
is scattered at 180 degrees
(backward)
MIN ENERGY TRANSFER -->
electron scattered at 90
(sideways) and photon is
scattered at 0 degrees (for-
ward), no energy is trans-
ferred to the electron
NOTE: all of the photon en-
ergy cannot be transferred
to the electron, must always
be some energy available for
the scattered photon.
7. what is the relationship between the mass energy u_tr/ρ du_en/ρ always
transfer coefficient (u_tr/ρ) and the mass energy ab- u_tr/ρ includes radiative
sorption coefficient (u_en/ρ) losses, u_en/ρ does not
8. The quantity f_med (or f-factor) roentgen-to-rad conversion
factor
0.876 * (u_en/ρ)air/(u_en/-
ρ)med
as such, function of both
medium density and photon
energy
9. KERMA is defined as _______
, RAPHEX EXAM QUESTIONS WITH SCORED A+ SOLUTIONS/NEWEST UPD
Study online at https://quizlet.com/_h77htl
the energy per unit mass
transferred from incident
photons to charged particles
in the medium
(energy of charged particles
liberated by indirectly ioniz-
ing radiation)
10. Energy dependence of dosimeters: Energy dependence will be
a. radiographic film based on Atomic Number
b. radiochromic film a. A = 42.8
c. Al2O3 OSLD b. A = 6.84
d. LiF thermoluminescents c. A = 11.2
d. A = 8.2
In the kV range, ra-
diochromic film will have the
least energy dependence (as
in the Photoelectric effect
range, attenuation is pro-
portional to Z^3)
11. _____________ is the most accurate for measuring sur- a. extrapolation chamber
face dose according to AAPM TG 176,
a. extrapolation chamber the extrapolation chamber is
b. farmer chamber the gold standard for surface
c. plane parallel chamber dose measurement
d. OSLD chamber
e. film
12. The charge measured by an ionization chamber directly; inversely
is ___________ proportional to the pressure and as the pressure increases
or the temperature decreas-
Study online at https://quizlet.com/_h77htl
1. In the equation for radioactive decay, lambda repre- the fraction of atoms that de-
sents _________ cay per unit time
2. Purpose of rounded leaf ends for MLCs keep the geometric penum-
bra relatively constant for dif-
ferent leaf positions
3. Neutron contamination is greatest in a _______ beam c. 18 MV photon
a. 6 MV photon remember neutrons are pro-
b. 10 MV photon duced through photon in-
c. 18 MV photon teractions, begin happening
d. 6 MeV electron above 10 MV photons
e. 20 MeV electron
4. Loss of charged particle equilibrium is greatest in < 5x5; >= 15 MV
lung radiotherapy for field sizes _______ cm2 and pho- effect is greater for higher
ton energies _______ MV photon energies since the
average energy of the sec-
ondary electrons is greater.
effect is greater for small
field sizes, harder to main-
tain CPE in small space
5. What is the relationship between HVL1 and HVL2 for HVL1 < HVL2 always
a polyenergetic kV photon beam As a polyenergetic kV pho-
ton beam traverses a ma-
terial, lower-energy photons
will be preferentially attenu-
ated. Therefore, as the beam
travels farther into a mater-
ial, it will become hardened
and its average energy will
, RAPHEX EXAM QUESTIONS WITH SCORED A+ SOLUTIONS/NEWEST UPD
Study online at https://quizlet.com/_h77htl
increase. Therefore, the HVL
will increase as well.
6. Compton scattering angles for minimum and maxi- MAX ENERGY TRANSFER -->
mum energy transference electron scattered 0 degrees
(forward) and the photon
is scattered at 180 degrees
(backward)
MIN ENERGY TRANSFER -->
electron scattered at 90
(sideways) and photon is
scattered at 0 degrees (for-
ward), no energy is trans-
ferred to the electron
NOTE: all of the photon en-
ergy cannot be transferred
to the electron, must always
be some energy available for
the scattered photon.
7. what is the relationship between the mass energy u_tr/ρ du_en/ρ always
transfer coefficient (u_tr/ρ) and the mass energy ab- u_tr/ρ includes radiative
sorption coefficient (u_en/ρ) losses, u_en/ρ does not
8. The quantity f_med (or f-factor) roentgen-to-rad conversion
factor
0.876 * (u_en/ρ)air/(u_en/-
ρ)med
as such, function of both
medium density and photon
energy
9. KERMA is defined as _______
, RAPHEX EXAM QUESTIONS WITH SCORED A+ SOLUTIONS/NEWEST UPD
Study online at https://quizlet.com/_h77htl
the energy per unit mass
transferred from incident
photons to charged particles
in the medium
(energy of charged particles
liberated by indirectly ioniz-
ing radiation)
10. Energy dependence of dosimeters: Energy dependence will be
a. radiographic film based on Atomic Number
b. radiochromic film a. A = 42.8
c. Al2O3 OSLD b. A = 6.84
d. LiF thermoluminescents c. A = 11.2
d. A = 8.2
In the kV range, ra-
diochromic film will have the
least energy dependence (as
in the Photoelectric effect
range, attenuation is pro-
portional to Z^3)
11. _____________ is the most accurate for measuring sur- a. extrapolation chamber
face dose according to AAPM TG 176,
a. extrapolation chamber the extrapolation chamber is
b. farmer chamber the gold standard for surface
c. plane parallel chamber dose measurement
d. OSLD chamber
e. film
12. The charge measured by an ionization chamber directly; inversely
is ___________ proportional to the pressure and as the pressure increases
or the temperature decreas-
