Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
ENU4612 Quiz 1-2
| Question | Answer |
|---|---|
| Which statement best describes the primary difference between charged particulate radiations and uncharged radiations? | Charged particles interact through coulomb forces, uncharged radiations require catastrophic interactions |
| Which of the following are characteristics of heavy charged particle tracks? | Straight path with minimal deflection, Dense ionization along the track |
| Delta rays are energetic secondary electrons produced during heavy charged particle interactions with matter. T/F? | True |
| The Bragg-Kleeman rule is used to______ | Estimate ranges in different materials |
| Fast neutrons lose energy primarily through: | Elastic scattering with nuclei |
| For slow neutron detection, the most useful reactions produce: | Heavy charged particles |
| An experiment uses a narrow beam geometry to measure electron transmission through varying thicknesses of absorber material. Unlike heavy charged particles which show no attenuation until near their range, electrons show immediate attenuation because: | Electrons undergo large-angle scattering that removes them from the detector's field of view |
| The buildup factor B: | Is always greater than or equal to 1 |
| For electrons, the actual penetration depth compared to the CSDA range is: | Much less than the CSDA range due to tortuous scattering paths |
| Quality factors (Q) are used because | High LET radiations are more biologically damaging and Different radiations cause different biological damage for same absorbed dose |
| Compared to heavy charged particles of the same energy, fast electrons: | Have much lower stopping power |
| The minimum energy required for pair production is: | 1.022 MeV |
| Beta particles have what type of energy spectrum? | Continuous energy spectrum from zero to endpoint energy |
| Bremsstrahlung radiation is produced when | Fast electrons interact in matter and are decelerated |
| Annihilation radiation consists of | Two oppositely directed 0.511 MeV photons |
| Internal conversion electrons differ from beta particles in that they | Come from nuclear transitions rather than beta decay, Are monoenergetic, and Have energies given by E_e⁻ = E_ex - E_b |
| A ⁶⁰Co source has an initial activity of 100 mCi. After 10.54 years (t₁/₂ = 5.27 years), what is the remaining activity? | 25 mCi |
| Characteristic X-rays are produced when | Orbital electrons rearrange after atomic excitation |
| In (α,n) neutron sources using beryllium targets, which factor most significantly limits the neutron production efficiency? | Only about 1 in 10⁴ alpha particles actually react with Be |
| Calculate the specific activity (λAᵥ/M) of ¹⁴C (half-life = 5730 years). Given: Aᵥ = 6.02 × 10²³ nuclei/mol, M = 14 g/mol | 1.65 × 10¹¹ Bq/g |
| Auger electrons are characterized by | Low energies (few keV) and discrete energy spectrum |
| Self-absorption in radiation sources is most problematic for | Alpha particles and low-energy X-rays |
| Explain the process of characteristic X-ray production | orbital e is removd from a inner shell creates a vacancy filled by e from a outer shell When outer e transitions to fill vacancy, E diff between 2 shells released as chara X-ray photon who E = the diff in binding E between the int and fin shells |
| Why do beta particles have a continuous energy spectrum rather than discrete energies | Continuous because energy shared between beta particle and neutrino/anti-neutrino varies from decay to decay, ranging from zero to endpoint energy (Q-value) |
| In internal conversion, an excited nuclear state transfers its energy directly to an ____________ (usually from the K, L, or M shell) instead of emitting a ______________. | orbital electron, gamma ray |
| What are conversion electrons and how do they differ from beta particles? | Conversion electrons are monoenergetic electrons produced through the nuclear process of internal conversion, which differs fundamentally from beta particles that have a continuous energy spectrum. |
| What is valuable for energy calibration | Conversion electrons because they provide discrete, well-defined energy peaks rather than the broad spectrum characteristic of beta decay |
| What is "self-absorption" in radiation sources, and which types of radiation are most affected by it? Explain why source thickness matters for different radiation types | In thick materials, only atoms near surface can release photons that escape. Mainly affects soft radiation, which can only get through a few micrometers. Beta particles are less affected, while gamma rays and neutrons are the least affected |
| What are the 4 types of radiation? | Fast electrons, Heavy charged particles, Electromagnetic radiation, Neutrons |
| types of Charged Particulate Radiation | Fast electrons, Heavy charged particles |
| types of Uncharged Radiation | Electromagnetic radiation, Neutrons |
| what are Fast electrons | Beta particles (β⁺ or β⁻), energetic electrons from any process |
| what are Heavy charged particles | All energetic ions with mass ≥ 1 amu |
| what are Electromagnetic radiation | X-rays from electron shell rearrangement, gamma rays from nuclear transitions |
| what is neutron radiation | neutrons generated in nuclear processes further divided into slow neutron and fast neutron subcategories |
| Formula for specific activity | Specific Activity = (λAᵥ)/M |
| Formula for half life | t₁/₂ = ln(2)/λ |
| formula for wavelength | λ = 1.240 × 10⁻⁶/E or λ = (hc)/E where h is plancks constant and c is speed of light |
| what is plancks constant | h = Planck's constant (6.626 × 10⁻³⁴ J·s or 4.135 × 10⁻¹⁵ eV·s) |
| formula Energy-Frequency | E = hv where h is plancks constant |
| Decay equation | N =N0 e^−(λt) can also be written as ln(N₂/N₁) = -λt |
| Activity Equation | A =A0 e^−(λt) |
| Q-Value Equation | [ ΣMass of reactants) - ( Σmass of products) ] *931.5MeV |
| What is σ for Poisson | Poisson process: σ = √x̄ |
| formula for Experimental mean | Experimental mean: x̄ₑ = Σxᵢ/N |
| formula for sample variance | s² = (1/(N-1))Σ(xᵢ - x̄ₑ)² |
| formula for poisson probability | P(x) = (x̄ˣe^(⁻ x̄))/x! |
| basic probability equation based on mean | x̄ = pn |
| When is Gaussian approximation valid | Gaussian approximation is valid when x̄ ≥ 20, where it is identical to a smoothed poisson distribution |
| Net count formula | u = x -y where x is the total and y is the background |
| uncertainty formula for counts | √(x + y) where x is the total and y is the background |
| error propogation formula | σsubλ/λ = √[(σ₁/N₁)² + (σ₂/N₂)²] |
| why is the relationship σ = √x is unique to counting statistics and cannot be applied directly to Counting rates | The relationship σ = √x applies only to direct counts of random events because When x represents a rate (counts/time), it's calculated by dividing counts by time. The error propagation for division gives σrate = σcounts/time = √((counts)/time), not √rate. |
| why is the relationship σ = √x is unique to counting statistics and cannot be applied directly to Averaged measurements | The relationship σ = √x applies only to direct counts of random events because The average of N independent counts has reduced uncertainty by factor 1/√N. If each count has σ = √x, the average has σ = √x/√N = √(x/N), not √(average). |
| why is the relationship σ = √x is unique to counting statistics and cannot be applied directly to Background-subtracted counts | The relationship σ = √x applies only to direct counts of random events because Net = Total - Background involves subtraction of two counted quantities. Error propagation gives σnet = √(σ²total + σ²bg) = √(Ntotal + Nbg), not √(Nnet). |
Created by:
user-2062823