RAD 102 Final Exam Study Guide PDF

Unit 1 I. Intro and Overview- Atomic and Nuclear Structure Conversion of Units Ionization ○ Converting an atom to an Ion (an atom with a non-zero net charge) Atomic Notation ○ Atomic Number (Z) = # of protons in the nucleus ○ Neutron number (N)...

Unit 1 I. Intro and Overview- Atomic and Nuclear Structure Conversion of Units Ionization ○ Converting an atom to an Ion (an atom with a non-zero net charge) Atomic Notation ○ Atomic Number (Z) = # of protons in the nucleus ○ Neutron number (N)= # of neutrons in the nucleus ○ Mass Number (A)= # of Nucleons in the nucleus OR # of protons + # of neutrons ○ A= Z + N ○ Charge= net charge on the particle Isotope ○ Same Z, different N ○ ○ Note: ALWAYS the same element! Isobar ○ Same A, different Z, N ○ ○ Useful for Beta Decay 9isobaric transition) Isotone ○ Same N, different Z  ○ Isomer ○ Same N, Z, different energy levels ○ ○ m designates a metastable state ○ *see comparison chart II. Nuclear Reactions/ Radioactive Decay Chart of Nuclides Parent Daughter Balancing Nuclear Reactions ○ Conserved properties in a nuclear reaction Steps to balance an equation Conservation of Energy ○ Forms of Energy ○ Relevance of E= mc^2 III. Radioactive Decay- Decay Modes Decay Schematic: graphical representation of decay scheme; displays ENERGY  ○ Be able to read a schematic (find relevant info) ○ Be able to draw a basic schematic Common Conventions of a Decay Scheme ○ Z on the X-Axis - Atomic # (Z, Protons) Moving UP INCREASES Z (Protons) Moving DOWN DECREASES Z ○ N on the Y-axis - Energy Moving RIGHT INCREASES N (neutrons) Moving LEFT DECREASES N ○ Branching ratio: percentage/probability of a given decay mode ○ More info: Energy on Y-axis; X-axis is Atomic number (Z) Notation: Horizontal Lines = Energy states of nucleus —---- Diagonal Lines = Particle emissions (a, B) / \ Vertical Lines= Gamma Emissions |  Review Chart of Nuclides ○ Z on Y axis ○ N on X axis Decay Modes ○ List, define/describe, recognize a drawing/diagram of the decay modes/mechanisms for the decay modes above ○ Alpha- Move DOWN 2, LEFT 2 4 X 2 ○ Beta (+) Positron- Move DOWN 1, RIGHT 1 0 X +1 ○ Beta (-) Negatron- Move UP 1, LEFT 1 0 X -1 ○ Electron Capture/IC (Gamma)- 1 DOWN, 1 RIGHT 0 – X -1 1  IV. Decay Calculations Positron Annihilation (Beta +) ○ Electron + positron : conversion of mass to energy ○ Photon always emitted in opposite directions  Characteristic X-Ray Auger Electrions Units of Activity ○ Definition #1: decays per second, rate of decay ○ Definition #2: amounts of radionuclide that produces a given # of decays per second ○ Units: 1 Bq= 1 decay/s 1 Ci= 3.7 x 10^10 decay/s So, 1 Ci = 3.7 x 10^10 Bq Converting activity units CPM vs. Activity example and calculations ○ CPM = the number of events OBSERVED Radoactive Decay equations Decay Constant λ ○ Number of decays per unit time ○ Probability per unit time that a single nucleus will delay  ○ Half life ○ The time required for half of an amount of a radionuclide to decay N,λ,N0, e, t, T0.5, ln 2 ○ Simple Decay: example on page 80 of chapter 4 N = N0e^-λt N= # of atoms N0= # of atoms at time 0 Unit 2- 5, 6, 7, 8 Lecture 5- Energy, Activity and Decay How is the equation E=mc^2 related to radioactive decay (mass, energy. etc.) Define Q Value ○ Energy released by a nuclear reaction ○ Other names: Transition or Reaction Energy ○ Q >0 = energy released ○ Q 13.4 eV ○ Excitation: less dangerous, still harmful Does NOT causes ejection of an electron E< 13.4 eV Define/describe/recognize a drawing/diagram of: ○ X-ray emission ○ Auger Electron  Define/describe Direct/Indirect Ionizing Radiation Direct Ionization Indirect Ionization - Incident particle transfers to medoum - Incident particles creates a secondary - ALL CHARGED PARTICLES particle - Alpha - Secondary particle transfers energy to - Electrons/Photons medium - Protons - ALL NEUTRAL PARTICLES - Gamma/X-ray - Neutrons Charged Particle Interactions: ○ Why are charged particle interactions “like” magnets Because of Coulomb Interactions (force between charges) ○ What are coulomb interactions? The electrostatic interactions between electric charges and follow Coulomb’s Law  ○ What part(s) of matter are typically interacted with by charged particles Electrons and Nuclei ○ Define/desribe, compare/contrast Heavy vs Light charged particle interactions *most likley a short answer question Target in the atom= Electron Heavy Charged Particles Light Charged Particles - Protons - Interact with matter - Loose very LITTLE energy in any - Light Particles: Positron, Electron single collision - Interacts through Coulomb - Complete transfer needs MANY Interactions collisions - Can transfer up to ALL of the energy - SMALL changes in direction in any single collision - Complete transfer needs FEWER collisions - Can have LARGE changes in direction Define/describe/recognize a drawing/diagram of Bremmstrahlung radiation and its contribution to the generation of X-rays ○ “Breaking Radiation” - Radiation (energy loss) When a charged particle is deflected in a strong electric field it will release X-rays Not significant for heavy particles Interacts with the nucleus → deflected Range/Fate of beta (electrons) (also see study grid) X-ray Production ○ Define/describe/recognize figure of bremmstrahlung radiation and its contribution to the generation of X-rays Bremmstrahlung releases X-rays when interacting with the nucleus of an atom Lecture 7- Interaction of Radiation with Matter, Part 2 Neutral Particles Why are neutral particles “blind” ○ Blind to the atoms and electron clouds in matter ○ No cloud= Coulomb Force ○ Can’t act at range → bump into everything ○ Interactions are much less likely Photon interactions ○ Define photon Light particle; discrete “packet” of electromagnetic energy  ○ List/define/describe, recognize a drawing/diagram of the 4 interaction mechanqisms for photon interactions Photoelectric Effect Photon is absorbed and electron is ejected Transfers all of its energy; No photon exists after this interaction Compton Scattering Portion of the incident photon energy is transferred to the electron Scattered photon still exists Longer wavelength Pair Production Gamma ray interacts with strong electromagnetic force and converts to an electron and positron Photonuclear Nuclear reaction with photons; nucleis absorbes photon and nuclear reaction occurs ○ What is the facte of secondary electrons Secondary electrons can go on further to cause ionizations Loose energy via mechanisms or become apart of electrical current Cause Ionization and Excitation Define/describe HVL ○ Be able to estimate how many photons will pass with a given HVL, similar to half-life calculations (BASIC CALCULATIONS ONLY, YOU CAN USE A CALCULATOR BUT DO NOT NEED ONE) Lecture 8- Biological Effects of Radiation Which population has the biggest contribution to Radiation Exposure Data and what are the faults in using this data ○ Atomic Bomb Survivors ○ Faults: Very High Exposures Acute exposures vs chronic exposures Dose is not usually measures  Populations NOT representative Define/describe DNA direct vs. Indirect Interactions ○ DNA Direct: Radiation causes ionization in DNA on the strand itself ○ DNA Indirect: Radiation interactis with the intracellular fluid Produced free radicals Radicals attack and damage DNA Compare and contrast Deterministc vs. Stochastic effects *most likely going to be a short answer question ○ Deterministic: ALWAYS observed above a threshold dose (min. Dose to cause an effect) Severity of effect is proportional to dose HIGH DOSE= more severe injury Usually observed at higher doses “Rapid” onset after exposure ○ Stochastic: Probability of effect is proportional to dose Higher dose = more likely for effect to occur NO THRESHOLD DOSE Delayed onset after ANY exposure (cancer) Define acute vs. chronic exposure ACUTE CHRONIC - Exposure over a SHORT period of - Exposure over a LONG period of time time - LOW dose rate - HIGH dose rate  Define/describe the 5 main deterministic effects 1. Acute Radiation Syndroms (ARS)- Radiation sickness 2. Radiation Erythema - Radiation burns 3. Epilation- hair loss 4. Cataracts- eyes 5. Sterility- gonads What is the main stochastic effect? ○ Cancer; increased rate at HIGH dose ○ Any exposure increases risk of cancer Lecture 9- Radiation Detection and Dosimetry What is a gas filled detector ○ Geiger Muller ○ Ion Chambers ○ Describe the basic mechanism of the gas-filled detector Voltage applied across tube Radiation interacts with gas Electrons collect at anode Detector measures current What is a Roentgen ○ Old unit ○ Still in use practice What is a Geiger- Mueller Detector? ○ Be able to do a basic reading on a GM counter What is scintillation detector ○ What is PMT : where photons interact, converts a photon into many electrons What is a physical effect detector ○ Measures electrons produced ○ Determines both energy and count rate  What is a scintillation camera ○ What has essentially replaced film Radiation Dosimetry ○ Define dosimetry: Measurement of rad exposure External Dose Collects data over time (3 months standard) Does not provide any shielding ○ What is a dosimeter and what does it measure Unit 3- 9, 10, 11 Lecture 9. Radiation Protection and Safety Identify the units for: *SEE WORKSHEET* ○ Exposure ○ Absorbed dose ○ Dose equivalent ○ Effective Dose Absorbed dose and LET (high vs low LET and damage caused by both) Define CEDE ○ Committed Effective Dose Equivalent The whole body gamma dose that results in the same overall risk as the lifetime dose from an internal exposure/uptake event Internal doses Define TEDE ○ Total Effective Dose Equivalent ○ ALL external exposures, equivalent whole body doses What is Dosimetry Program ○ When may you request a copy of your report  ○ How long your personal record is kept What are the goals of radiation protection What are enforcement/regulating bodies responsible for ○ What is the NRC ○ What are agreement states (Is NV an aggrement state?) ○ Describe the responsibilities of: EPA FDA OSHA DOT DOE And other agencies What are the 2 main Radiation Protection goals? *revisit the definitions of deterministic and stochastic What are the occupational dose limits set byt the NRC: ○ 1 stochastic limit ○ 3 deterministic limits What is ALARA? ○ As Low As Reasonably Achieveable Describe how each TIME, DISTANCE, and SHIELDING help protect one from radiation exposure What are the 3 types of contamination?