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111 Cards in this Set
- Front
- Back
- 3rd side (hint)
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Nucleus: Contains ?
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Protons & Neutrons
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Neutrons:
Charge = ? Rest mass = ? Approx SAME size as ? Approx 1800 X the size of ? |
Charge = NO Charge
Rest mass = 939.6 MeV Approx SAME size as PROTON Approx 1800 X the size of electron |
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Protons:
Charge = ? Rest mass = ? Approx SAME size as ? Approx 1800 X the size of ? |
Charge = "+" Charge
Rest mass = 938.3 MeV Approx SAME size as NEUTRON Approx 1800 X the size of electron |
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Electrons:
Charge = ? Rest mass = ? Approx size ? |
Charge = " - "
Rest mass = 0.511 MeV (NOTE: 0.511 MeV=511KeV; **Watch Units**) Approx size = very small |
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Isotopes
(examples C-12 & C-14) |
Same Atomic # (Z)
[Therefore same Protons) |
IsotoPes ("P" hint)
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Isotones
(examples I-131 & Xe-132) |
Same # of Neutrons
(I-131 & Xe-132 both have 58 Neutrons) |
IsotoNes ("N" hint)
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Isobar
(examples: N-14 & C-14) |
Have same "A" (mass #) A = # Protons + # Neutrons
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IsobAr
("A" hint = Same A; aka mass#) |
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Nuclides: A/Z X (A=superscript & Z=subscript)
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A=superscript = Mass # = P+N
Z=subscript=Atomic # = P |
X=Element Symbol
A=superscript=Mass # Z=subscript=Atomic # |
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14/6 C: How many neutrons?
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8
A=14, Z=6; (14-6=8) |
A=superscript = Mass # = P+N and Z = P, so A-Z=Neutrons
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Isomer: 3 statements + 1 example
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Isomer example = T-99m
1) Isomer=SAME Z, A & N 2) EXTREMELY short half-life, i.e. 1x10(-10)sec 3) Metastable states |
IsoMer
("M" hint = metastable) |
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Stability: Higher Z elements, list 2 statements
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1) Higher Z elements have HIGHER Binding Energies (electron shells) - therefore the attractive force of the electrons will be higher
2) If Z>20, #Neutrons > # Protons (in other words, if you have more protons, then you need more "glue") |
1) neutrons -vs- protons (glue?)
2) Binding Energies (attractive force) |
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Activity Levels
(4 Examples of Ci level) |
1) Co-60 (Teletherapy); intitally loaded w/9,000 - 10,000 Ci
2) Gamma Knife; initially loaded w/ 6,600 Ci 3) Cs-137 (Blood Irradiation); initially loaded w/ 50 Ci 4) Ir-192 (HDR); initially loaded w/ 10 Ci |
1) Co-60
2) Gamma Knife 3) Cs-137 4) Ir-192 |
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Activity Levels
(4 Examples of mCi level) |
1) LDR
2) I-131 ablations 3) Tc-99m 4) PET, loaded w/ 15mCi FDG |
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Activity Levels
(2 Examples of micro-Ci level) |
1) "Other" nuc. med.
2) "Check source", loaded w/ 5 -10 micro-Curie Cs-137 |
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Gamma Rays, originate ____
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from the NUCLEUS
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X-Rays, originate (2 answers/types)
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1) CHARACTERISTIC
2) BREMSTRAHLUNG |
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Characteristic X-Rays: Occur when ____
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An orbital e- is ejected from the atom & an outer orbital e- falls down to fill in
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Bremstrahlung X-Rays: occur when _____
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When a charged particle (i.e. e-) is accelerated & deflected from passing by the nucleus.
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Characteristic X-Rays: Energy level is ____
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**Discrete** (aka Energy is the difference between the energy levels). Can be a "cascade".
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Bremstrahlung X-Rays, also described as _____
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"Braking" (Decelerating) Radiaiton
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"B"remstrahlung
"B"raking |
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Characteristic X-Rays: Energy is radiated off in form of ____
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Electromagnetic (EM) Radiation
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Bremstrahlung X-Rays: Energy form is _____
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Electromagnetic (EM) Radiation, when the particle loses part of it's energy
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the particle loses part of it's energy
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Bremstrahlung INCREASE with:
1) Z (Increasing or Decreasing Z?) 2) Energy (Increasing or Decreasing electron Energy?) |
Brems ~ Z & ~ E; aka...INCREASE with
INCREASE in Z (therefore Tungsten or Gold) and INCREASE in electron Energy |
is proportional to
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Bremstrahlung X-Rays: Energy level is _____
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**Continuous SPECTRUM** (E ave = E max/3)
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What is the most predominant type of X-Ray?
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BREMSTRAHLUNG is the most predominant in linac production of X-Rays (99.9%)
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99.9%
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Difference in Energy levels: Characteristic -vs- Bremstrahlung
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Characteristic = DISCRETE & Bremstrahlung = SPECTRUM
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NO HINT!
YOU NEED TO KNOW THIS! |
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Stated (Peak) Energy for 18 MVx:
1) Max E = ? 2) Ave E = ? |
18 MV:
1) Max E = 18 MeV 2) Ave E = 6 MeV (aka 18/3) |
1/3 rule
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Stated (Peak) Energy for 6 MVx:
1) Max E = ? 2) Ave E = ? |
6 MV:
1) Max E = 6 MeV 2) Ave E = 2 MeV (aka 6/3) |
1/3 rule
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Stated (Peak) Energy for 4 MVx:
1) Max E = ? 2) Ave E = ? |
4 MV:
1) Max E = 4 MeV 2) Ave E = 1.33 MeV (aka 4/3) [FYI: Co-60 ~ 1.25 MeV] |
1/3 rule
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Stated (Peak) Energy for 120 kVp:
1) Max E = ? 2) Ave E = ? |
1) Max E = 120 keV
2) Ave E = 40 to 60 keV (aka approx 1/2 rule, due to filtering) |
1/2 rule
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Activity Levels
(4 Examples of mCi level) |
1) LDR
2) I-131 ablations 3) Tc-99m 4) PET, loaded w/ 15mCi FDG |
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Activity Levels
(2 Examples of micro-Ci level) |
1) "Other" nuc. med.
2) "Check source", loaded w/ 5 -10 micro-Curie Cs-137 |
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Equilibrium (definition)
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Decay at the SAME Activity RATE.
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Tp>>>Td
λp<<<λd ------------ ex1: Ra-226 → Rn-222 ex2: Sr-90 → Yr-90 |
Secular Equilibrium
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ex1: Ra-226 → Rn-222
ex2: Sr-90 → Yr-90 |
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Tp>Td
λd>λp -------------- ex: Mo-99 → Tc-99m |
Transient Equilibrium
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ex: Mo-99 → Tc-99m
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Td>Tp (aka Tp<Td)
λp>λd |
NO Equilibrium
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Activity
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Used for defining the Amount of Radioactive material
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Activity
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Disintegration of 1 gram Ra-226 = 1 Ci
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1 Ci = ? disintegrations/sec
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3.7 x 10(10) dps
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1 mCi = ? disintegrations/sec
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3.7 x 10(7) dps
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1 µCi = ? disintegrations/sec
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3.7 x 10(4) dps
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1 Bq (new unit) is = ?
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1 dps
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Ci -vs- dps - vs- Bq
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1 Ci = 3.7 x10(10)dps = 3.7 x10(10)
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"The measurement of Exposure in Air" is the definition of ?
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Roentgen
(Remember: in Air & is NOT a dose) |
AIR !!!!!
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1 R = ? rad
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1 R = 0.873 rad
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1 R = ? J/kg air
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1 R = 0.00873 J/kg air
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1 R = ? C/kg air
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1 R = 2.58 x 10(-4) C/kg air
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1 R = esu/cc air
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1 R = 1 esu/cc air
(esu="electrostatic unit") |
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Dose Equivalent, unit is ?
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Rem, is the measurement of Dose Equivalent
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Dose Equivalent (formula)
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Dose Equivalent = rad x QF x modifying factor = D x Q x N
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1 Sv = ? rem
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1 Sv = 100 rem
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1 Sv = ? J/kg
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1 Sv = 1 J/kg
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Why are Quality Factors needed?
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Since not all radiation is EQUAL as far as damage (or dose equivalents)
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What 5 types of radiation has a QF of 1:
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x, e-, B-, B+, gamma
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What 1 type of radiation has a QF of 5: (2 was old QF, new QF=5)
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Thermal Neutrons (aka "Slow Neutrons")
• eV range |
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What 1 type of radiation has a QF of 10:
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Protons
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What 1 type of radiation has a QF of 20:
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Alpha (α), aka "Fast Neutrons"
• KeV-MeV range |
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Absorbed Dose, unit is ?
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Rad is the unit for Absorbed Dose.
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1 rad = ? cGy
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1 rad = 1 cGy
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1 Gy = ? rad
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1 Gy = 100 rad
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1 Gy = ? J/kg
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1 Gy = 1 J/kg (Formal definition)
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Formal definition
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Alpha Decay leads to: A ?, Z ?
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Alpha Decay leads to : A-4, Z-2
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Alpha Decay, occurs mainly in: ?
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Alpha Decay, occurs mainly in Heavy elements, i.e. Z>82.
(Exs: Uranium, Thorium, Plutonium) |
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Alpha Decay, range: ?
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Alpha Decay has a SHORT range in Air (~ 4cm)
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Alpha Decay, Kind of Energy: ?
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Discrete Energy, i.e. 5 to 10 MeV
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Alpha Decay, Specific Ionization: ?
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Specific Ionization: 5000 ion pairs/mm, i.e. a lot of energy!
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B- Decay leads to: Z ?, N ?
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B- Decay leads to : Z+1, N-1
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B- Decay, Type of Energy: ?
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Spectrum of Energies (E ave=E max/3)
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B+ Decay leads to: Z ?, N ?
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B+ Decay leads to:
Z-1, N+1 |
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B+ Decay, Type of Energy: ?
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Spectrum of Energies.
E = 1/3 Emax (aka Eave = Emax/3) |
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B- Decay, example:
Cs-137 → (?) |
Cs-137 → 662 keV gamma
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Which type of Radioactive Decay is the basis for PET scanning?
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B+ is used for PET scanning
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State the fundamentals of PET scanning
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FYI: B+ ~ e+
1) e+ combines w/e-, then annihilation 2) results in two 511keV (2 x 511keV = 1.022 MeV) 3) they are 180degrees apart |
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B+ threshold energy = ?
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B+ threshold energy = 1.022MeV
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Electron Capture, leads to: Z ?, N ?
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Electron Capture, leads to: Z-1, N+1
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Electron Capture, Type of Energy: ?
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Does NOT have a "threshold" (ex: can be < 1.022 MeV)
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Electron Capture, parent (?)
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Electron Capture, has a proton rich parent (ex: excess of protons)
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Electron Capture, is followed by (?) or (?)
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Electron Capture, is followed by Characteristic x-rays or Auger electrons
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Internal Conversion, results in: Z (?), N (?) , A (?)
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Internal Conversion, results in: NO Change in Z, N, A
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Internal Conversion, Type of Energy: ?
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Internal Conversion, transformation of Energy from nucleus to orbital electron ( K or L shell)
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Internal Conversion, results in: (?) or (?)
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Internal Conversion, results in: Characteristic x-rays or Auger electrons
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In Internal Conversion, a ___ ___ is ejected
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In Internal Conversion, a DISCRETE ELECTRON is ejected
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Radioactivity: Decay Constant (formula)
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λ =0 .693 / T1/2
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Radioactivity: Activity remaining (formula)
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A Ao e-λt
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Radioactivity: Average Lifetime (formula)
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τ = 1.44 T1/2
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Half-life:
Pd-103 |
17 days
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d
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Half-life:
I-125 |
60 days
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d
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Half-life:
Ir-192 |
74.2 days
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d
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Half-life:
Co-60 |
5.26 yrs
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y
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Half-life:
Cs-137 |
30.1 yrs
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y
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Half-life:
Ra-226 |
1600 yrs
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yrs
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Ir-192, Decays ~ 1% every (?)
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~ 1% every DAY
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Co-60, Decays ~ 1% every (?)
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~ 1% every MONTH
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Cs-137, Decays ~ 1% every (?)
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~ 1% every 6 Months
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1st Half life, leaves (?) % Left
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50%
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2nd Half life, leaves (?) % Left
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25%
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3rd Half life, leaves (?) % Left
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12%
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4th Half life, leaves (?) % Left
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6%
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5th Half life, leaves (?) % Left
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3%
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Photoelectric Effect:
Energy Range = (?) |
Photoelectric Effect:
Energy Range = 50keV |
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Photoelectric Effect:
relationship with Z = (?) |
Photoelectric Effect is proportional to Zcubed
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Photoelectric Effect:
relationship with E = (?) |
Photoelectric Effect is proportional to 1 / Ecubed
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Contribution:
1) @ 15 keV=(?) % PE, CS, PP |
@ 15 keV:
95% PE, 5% CS, 0% PP |
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Contribution:
2) @ 25 keV=(?) % PE, CS, PP |
@ 25 keV:
50% PE, 50% CS, 0% PP |
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Contribution:
3) @ 4 MeV=(?) % PE, CS, PP |
@ 4 MeV:
0% PE, 94% CS, 6% PP |
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Contribution:
4) @ 25 MeV=(?) % PE, CS, PP |
@ 25 MeV:
0% PE, 50% CS, 50% PP |
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Photon Interactions/Relations:
PE is predominant @ E (?) |
PE is predominant @ E<30keV
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Photon Interactions/Relations:
PE is propotional to (?) and (?) |
PE is ~ Zcubed and 1/Ecubed
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Photon Interactions/Relations:
Compton Scattering is predominant @ E (?) |
Compton Scattering is predominant @ E in Therapy Range (MeV)
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Photon Interactions/Relations:
Compton Scattering is (dependent or independent) of Z |
Compton Scattering is relatively INDEPENDENT of Z
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Photon Interactions/Relations:
Pair Production is proportional to (?) |
Pair Production is proportional to Zsquared
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