NHR Rad520 Radioactivity Flashcards
What are A, B, C, and D and what Model is this?
Bohr’s Model
A = Nucleus
B = 1st/k shell (2 electrons)
C = 2nd/L shell (8 electrons)
D = 3rd/M shell (18 electrons)
Bohr’s model _____ calculate the max number of electrons in each respective shell.
2n2
Identify A, B, and C:
A = atomic number or proton number (Z)
B = Elemental Symbol
C = Atomic Mass in Amu
Find the energy converted using E = mC2 of the following:
0.0989 amu
Nuclear Binding Energy: 1 eV = 1.602 x 10^-19 J
Complete the table:
What is the equation for radioactive decay?
Nt = number of atoms after time
No = original number of atoms
t = time elapsed
λ = decay constant (number of atoms decaying per unit of time)
What is the decay constant (λ)?
How do you calculate activity (decay, disintegrations per unit of time)?
At = number of atoms after time
Ao = original number of atoms
t = time elapsed
λ = decay constant (number of atoms decaying per unit of time)
True or False: 1 Bq = 2.7 x 10^-11 Ci
True
True or False: 1 Ci = 3.7 x 10^10 Bq
True
How do you calculate mean or average life (τ)?
What is the average life for Radium^226?
What is this decay method?
Alpha α
What is this decay method?
Alpha α
What is this decay method?
β; β negative and β positive
What is this decay method?
electron capture
A Flattening Filter _____ the average energy and _____ the total radiation quantity?
A. Decreases, Increases
B. Decreases, decreases
C. Increases, decreases
D. Increases, Increases
C. Increases, decreases
From Quiz 1
Which of the following decay modes is most prominent in the heavier elements in the periodic table?
A. Electron Capture
B. Alpha
C. Beta negative
D. Beta positive
B. Alpha
From Quiz 1
An increase in kVp has a _____ effect on electron output, while mAs has a _____ effect.
A. Direct, direct
B. squared, squared
C. Direct, squared
D. Squared, direct
D. Squared, direct
From Quiz 1
Which of the following photon interactions results in a scattered photon with less energy and an ejected orbital electron?
A. Coherent scatter
B. Compton scatter
C. Photoelectric effect
D. Pair Production
B. Compton scatter
From Quiz 1
Which of the following radiation measurement devices utilizes a p-type and n-type junction?
A. TLD
B. Silicon diode
C. Film
D. Farmer chamber
B. Silicon diode
From Quiz 1
Which of the following organizations would be utilized to calibrate an ion chamber for a clinical site?
A. ADCL
B. PSDL
C. IAEA
D. AAPm
A. ADCL
From Quiz 1
How would an increase in SSD affect the geometric penumbra width?
A. No effect
B. Increase
C. Depends on isotope used
D. Decrease
B. Increase
From Quiz 1
Compared to photon mode, electron mode uses a _____ machine current and the _____ on the carousel.
A. Higher, scattering foil
B. Lower, scattering foil
C. Lower, flattening filter
D. Higher, flattening filter
B. Lower, scattering foil
From Quiz 1
How long would it take a 15 Ci iridium^192 source to decay to 11 Ci? What’s the base equation?
From Quiz 1
What is the μ for a beam that is attenuated 95% by a 5 mm piece of lead? What is the base problem?
From Quiz 1
How many HVLs are in the beam path when there is 300 cGy/min without shielding & 42 cGy/min with shielding?
Find what is transmitted then find the HVLs.
(Ix/(Io) = (42 cGy/min)/(300 cGy/min) => 0.14 transmitted
0.5n = 0.14 => ln 0.5n = ln 0.14 => n = (ln 0.14)/(ln 0.5) => n = 2.837
What is the intensity of a beam passing through a filter that has a linear attenuation coefficient of 0.019 cm-1 and a thickness of 1.5 cm? The original intensity was 200 cGy/min.
Equation: Ix = Io e^-μx
Ix = ???
Io = 200 cGy/min
μ = 0.019 cm^-1
x = 1.5 cm
Ix = (200 cGy/min) e^-0.0285
Ix = (200 cGy/min) (0.972)
Ix = 194.4 cGy/min
