We have completed a discussion of one of the photon interaction processes, the photoelectric effect. We will now begin a discussion of the process of
|
|
- Nora Pope
- 5 years ago
- Views:
Transcription
1 We have completed a discussion of one of the photon interaction processes, the photoelectric effect. We will now begin a discussion of the process of coherent scatter. 1
2 In this lecture we are going to identify and describe the process of coherent scatter and learn how to calculate cross sections for coherent scatter. Recall that the cross section is a measure of the probability of an interaction occurring. It is actually the attenuation coefficient per unit incident fluence density. 2
3 Let s first describe coherent scatter from a qualitative point of view. We start with an incident photon. We look upon the photon in this case as an electromagnetic wave. As the electromagnetic wave passes near an atom, it sets the electrons in the atom in motion. The electrons oscillate along with the electromagnetic wave. But what happens when electrons oscillate? They accelerate and decelerate so they emit energy in the form of electromagnetic radiation. Note that the frequency of oscillation, hence the energy of the scattered radiation, is identical to the frequency of oscillation of the incident radiation. The angle of scatter is very small, and most of these interactions are electronic interactions. There can be scatter from nuclei but it is relatively improbable. Scatter is primarily with electrons. We will be looking at the motion of the electrons caused by the electromagnetic wave that corresponds to the incident radiation. We are going to try to calculate how much radiation is emitted from these electrons when they oscillate. That s coherent scatter. 3
4 We will start by deriving an equation for Thomson scatter. Thomson scatter was really the first theoretical treatment of classical scatter. The problem with Thomson scatter is that it s wrong. The calculated cross section does not agree with experimental values. However, the cross section that we derive from Thomson scatter is included in all the scattering equations. So when we look at more sophisticated models for coherent scatter, we will see the Thomson scatter cross section as being the first approximation to the model; everything else will be a modification of it. So that is why we will calculate the effect of Thomson scatter first. It also gives us a good picture for a quantitative description of what is really going on. 4
5 First of all, what do we mean by the differential scatter cross section? Differential scatter cross section is defined as the probability that an incident photon produces a scattered photon at a specified solid angle. So the units of differential scatter cross section are a unit of area, per electron or per atom, depending on whether it s an electronic cross section or an atomic cross section, per unit solid angle. The unit of solid angle that we use is the steradian. There are 4π steradian in one sphere. We will see some applications of a differential cross section a little bit later on in this lecture. 5
6 What we really want to be able to do is to follow the energy. Rather than just calculating the differential cross section, we really want to determine the fraction of energy that s scattered in a particular direction. We obtain the fraction of energy scattered by multiplying the scattering cross section times the electron areal density times the angle subtended by the detector. Electron areal density is expressed as electrons per square meter, per square centimeter, etc., whatever unit. The angle subtended by the detector is expressed in steradian. The calculation of energy scattered in a particular direction is going to be our eventual goal in any of these treatments. So we derive the scattering cross section, multiply it by the areal density of electrons, and multiply that by the angle subtended by the detector. 6
7 A typical calculation is to determine the fraction of energy scattered per electron aerial density per solid angle subtended by the detector. Once again, we repeat the mantra, follow the energy. That s going to be our game plan for this lecture. 7
8 So how do we derive the scatter cross section using the model for Thomson scatter? Let s start with an electromagnetic wave. Recall from your E&M course that an electromagnetic wave has two components, an electric vector and magnetic vector. These are at right angles to each other and they are moving with a velocity c. Let s assume that the incident photon is unpolarized, so there are components of the electric field that are at right angles to each other. We ll designate the two components as E 1 and E 2. These two components are both perpendicular to the direction of propagation. This is your basic freshman year electrodynamics. This electric field comes in and interacts with an electron, causing the electron to accelerate. The acceleration of the electron induces an electric field. What we want to determine is the fraction of energy that s scattered in this induced electric field as related to the original incident electric field. 8
9 Let s take an electric field and have this electric field interact with a free electron. What is the force on the free electron due to the electric field? The force is proportional to the electron charge and the electric field vector. We have a component of force in each direction, direction 1 and direction 2, the two directions that are perpendicular to the direction of propagation of the electromagnetic wave. The force is a constant times the charge times the electric field. The constant is the same constant as that in the Coulomb force equation, Nt m 2 /C 2. That s the force now on the free electron. What is now going to happen to the electron? 9
10 The electron s going to accelerate. Recall the basic equation F = ma. I hope you still remember that equation from your freshman physics course. We have determined what the force is. We can now relate the force to the acceleration of the electron. The acceleration is equal to the force divided by the mass of the electron m 0. So the acceleration is a constant times the electric charge times the electric field component divided by the mass of the electron. So far so good. Now from classical electricity and magnetism, the charge will radiate energy in the form of an electromagnetic wave. This is the scattered radiation whose intensity we are going to try to calculate. (I hope you are all with me so far in this derivation. The derivation so far is pretty straightforward, I think). 10
11 So we have an accelerated electron at the origin that s accelerating with components a 1 and a 2 parallel to the incident electric fields E 1 and E 2. This acceleration is going to produce an electric field at some point Q, a distance r from the accelerating electron. The component of the electric field that s produced in the E 1 direction is denoted as E 1 and the component of the electric field produced in the E 2 direction is denoted as E 2. Note that these two directions must be perpendicular to the vector r. 11
12 Let s figure out what this electric field vector is at the point Q. In the E 1 direction, the electric field is related to the acceleration, by this equation, which we obtain from basic electromagnetic theory. It is equal to the acceleration times the charge on the electron times the sine of the angle between E 1 and the line from the origin to Q, all this divided by c 2 times r. Let s plug in the value of a 1 into this equation. We find that the electric field is equal to the Coulomb constant times the square of the electron charge multiplied by the electric field component E 1 times the sine of the angle psi divided by the mass of the electron times c 2 r. (Is everyone with me so far?) 12
13 If we multiply the Coulomb force constant times the square of the charge of the electron and divide this by the mass of the electron times c 2, we obtain a constant that has the units of distance. This quantity is called the classical radius of the electron. It has the value of times m. This is a very small number. The diameter of the nucleus is m, so this distance is about two orders of magnitude smaller than the nuclear diameter. If we plug this quantity in to our previous equation, we find that the electric field in the number 1 direction is proportional to the incident electric field in the same field times the ratio of the classical radius of the electron to the distance of interaction times the sine of the angle that the vector from the initial interaction point to our measurement point makes with the incident electric field direction. 13
14 So we have now computed the magnitude of one component of the electric field. It turns out that the second component gives us a similar equation but we find that E 2 is parallel to E 2 so we have that E 2 using the same argument we used to determine E 1 is r 0 over r times E 2 times the sine of 90 o. What we are saying here is that magnitude of the electric vector of the scattered radiation is going to be a very small fraction of the magnitude of the electric vector of the incident radiation because r 0 is so very much smaller than any distance we measure in this process. Let s stop our discussion at this point and let this sink in for a few days and we will continue discussing coherent scatter at our next lecture. 14
For the next several lectures, we will be looking at specific photon interactions with matter. In today s lecture, we begin with the photoelectric
For the next several lectures, we will be looking at specific photon interactions with matter. In today s lecture, we begin with the photoelectric effect. 1 The objectives of today s lecture are to identify
More informationNotes on x-ray scattering - M. Le Tacon, B. Keimer (06/2015)
Notes on x-ray scattering - M. Le Tacon, B. Keimer (06/2015) Interaction of x-ray with matter: - Photoelectric absorption - Elastic (coherent) scattering (Thomson Scattering) - Inelastic (incoherent) scattering
More informationThe next three lectures will address interactions of charged particles with matter. In today s lecture, we will talk about energy transfer through
The next three lectures will address interactions of charged particles with matter. In today s lecture, we will talk about energy transfer through the property known as stopping power. In the second lecture,
More informationThe Bohr Model of Hydrogen
The Bohr Model of Hydrogen Suppose you wanted to identify and measure the energy high energy photons. One way to do this is to make a calorimeter. The CMS experiment s electromagnetic calorimeter is made
More informationWaves & Oscillations
Physics 42200 Waves & Oscillations Lecture 32 Electromagnetic Waves Spring 2016 Semester Matthew Jones Electromagnetism Geometric optics overlooks the wave nature of light. Light inconsistent with longitudinal
More informationChapter 1: Useful definitions
Chapter 1: Useful definitions 1.1. Cross-sections (review) The Nuclear and Radiochemistry class listed as a prerequisite is a good place to start. The understanding of a cross-section being fundamentai
More informationNuclear Physics Fundamentals and Application Prof. H. C. Verma Department of Physics Indian Institute of Technology, Kanpur. Lecture 2 Nuclear Size
Nuclear Physics Fundamentals and Application Prof. H. C. Verma Department of Physics Indian Institute of Technology, Kanpur Lecture 2 Nuclear Size So, I have given you the overview of nuclear physics.
More informationThis is the last of our four introductory lectures. We still have some loose ends, and in today s lecture, we will try to tie up some of these loose
This is the last of our four introductory lectures. We still have some loose ends, and in today s lecture, we will try to tie up some of these loose ends. 1 We re going to cover a variety of topics today.
More informationPolarization. Polarization. Physics Waves & Oscillations 4/3/2016. Spring 2016 Semester Matthew Jones. Two problems to be considered today:
4/3/26 Physics 422 Waves & Oscillations Lecture 34 Polarization of Light Spring 26 Semester Matthew Jones Polarization (,)= cos (,)= cos + Unpolarizedlight: Random,, Linear polarization: =,± Circular polarization:
More informationOutline. Chapter 6 The Basic Interactions between Photons and Charged Particles with Matter. Photon interactions. Photoelectric effect
Chapter 6 The Basic Interactions between Photons and Charged Particles with Matter Radiation Dosimetry I Text: H.E Johns and J.R. Cunningham, The physics of radiology, 4 th ed. http://www.utoledo.edu/med/depts/radther
More information99 Years from Discovery : What is our current picture on Cosmic Rays? #6 How cosmic rays travel to Earth? Presented by Nahee Park
99 Years from Discovery : What is our current picture on Cosmic Rays? #6 How cosmic rays travel to Earth? Presented by Nahee Park #5 How do Cosmic Rays gain their energy? I. Acceleration mechanism of CR
More informationIn today s lecture, we want to see what happens when we hit the target.
In the previous lecture, we identified three requirements for the production of x- rays. We need a source of electrons, we need something to accelerate electrons, and we need something to slow the electrons
More informationRadiation Quantities and Units
Radiation Quantities and Units George Starkschall, Ph.D. Lecture Objectives Define and identify units for the following: Exposure Kerma Absorbed dose Dose equivalent Relative biological effectiveness Activity
More informationPhysics 3312 Lecture 9 February 13, LAST TIME: Finished mirrors and aberrations, more on plane waves
Physics 331 Lecture 9 February 13, 019 LAST TIME: Finished mirrors and aberrations, more on plane waves Recall, Represents a plane wave having a propagation vector k that propagates in any direction with
More informationParticle Detectors and Quantum Physics (2) Stefan Westerhoff Columbia University NYSPT Summer Institute 2002
Particle Detectors and Quantum Physics (2) Stefan Westerhoff Columbia University NYSPT Summer Institute 2002 More Quantum Physics We know now how to detect light (or photons) One possibility to detect
More informationLesson Plan. 1) Students will be aware of some key experimental findings and theoretical
Aleksey Kocherzhenko Lesson Plan Physical Chemistry I: Quantum Mechanics (this is a sophomore/junior-level course) Prerequisites: General Chemistry, Introductory Physics, Calculus, Differential Equations
More information1. Why photons? 2. Photons in a vacuum
1 Photons 1. Why photons? Ask class: most of our information about the universe comes from photons. What are the reasons for this? Let s compare them with other possible messengers, specifically massive
More informationNuclear Physics Fundamental and Application Prof. H. C. Verma Department of Physics Indian Institute of Technology, Kanpur
Nuclear Physics Fundamental and Application Prof. H. C. Verma Department of Physics Indian Institute of Technology, Kanpur Lecture - 5 Semi empirical Mass Formula So, nuclear radius size we talked and
More informationSolution to Proof Questions from September 1st
Solution to Proof Questions from September 1st Olena Bormashenko September 4, 2011 What is a proof? A proof is an airtight logical argument that proves a certain statement in general. In a sense, it s
More informationPSI AP Physics How was it determined that cathode rays possessed a negative charge?
PSI AP Physics 2 Name Chapter Questions 1. How was it determined that cathode rays possessed a negative charge? 2. J. J. Thomson found that cathode rays were really particles, which were subsequently named
More informationLecture 10 Diatomic Vibration Spectra Harmonic Model
Chemistry II: Introduction to Molecular Spectroscopy Prof. Mangala Sunder Department of Chemistry and Biochemistry Indian Institute of Technology, Madras Lecture 10 Diatomic Vibration Spectra Harmonic
More informationThe Atom. Result for Hydrogen. For example: the emission spectrum of Hydrogen: Screen. light. Hydrogen gas. Diffraction grating (or prism)
The Atom What was know about the atom in 1900? First, the existence of atoms was not universally accepted at this time, but for those who did think atoms existed, they knew: 1. Atoms are small, but they
More informationMITOCW watch?v=wr88_vzfcx4
MITOCW watch?v=wr88_vzfcx4 PROFESSOR: So we're building this story. We had the photoelectric effect. But at this moment, Einstein, in the same year that he was talking about general relativity, he came
More informationAt the conclusion of this lesson the trainee will be able to: a) Write a typical equation for the production of each type of radiation.
RADIOACTIVITY - SPONTANEOUS NUCLEAR PROCESSES OBJECTIVES At the conclusion of this lesson the trainee will be able to: 1. For~, p and 7 decays a) Write a typical equation for the production of each type
More informationEmphasis on what happens to emitted particle (if no nuclear reaction and MEDIUM (i.e., atomic effects)
LECTURE 5: INTERACTION OF RADIATION WITH MATTER All radiation is detected through its interaction with matter! INTRODUCTION: What happens when radiation passes through matter? Emphasis on what happens
More informationSemiconductor Optoelectronics Prof. M. R. Shenoy Department of physics Indian Institute of Technology, Delhi
Semiconductor Optoelectronics Prof. M. R. Shenoy Department of physics Indian Institute of Technology, Delhi Lecture - 18 Optical Joint Density of States So, today we will discuss the concept of optical
More informationRecap Lecture + Thomson Scattering. Thermal radiation Blackbody radiation Bremsstrahlung radiation
Recap Lecture + Thomson Scattering Thermal radiation Blackbody radiation Bremsstrahlung radiation LECTURE 1: Constancy of Brightness in Free Space We use now energy conservation: de=i ν 1 da1 d Ω1 dt d
More informationPHYSICS 107. Lecture 27 What s Next?
PHYSICS 107 Lecture 27 What s Next? The origin of the elements Apart from the expansion of the universe and the cosmic microwave background radiation, the Big Bang theory makes another important set of
More informationThe Structure of the Atom
The Structure of the Atom Chapter 4 in Rex and Thornton s Modern Physics Wed. October 26, 2016 S 1 In this chapter... S We ll explore how our understanding of atomic structure developed S Ancient Greek
More informationStructure of the Atom. Thomson s Atomic Model. Knowledge of atoms in Experiments of Geiger and Marsden 2. Experiments of Geiger and Marsden
CHAPTER 4 Structure of the Atom 4.1 The Atomic Models of Thomson and Rutherford 4. Rutherford Scattering 4.3 The Classic Atomic Model 4.4 The Bohr Model of the Hydrogen Atom 4.5 Successes & Failures of
More informationSemiconductor Optoelectronics Prof. M. R. Shenoy Department of Physics Indian Institute of Technology, Delhi
Semiconductor Optoelectronics Prof. M. R. Shenoy Department of Physics Indian Institute of Technology, Delhi Lecture - 20 Amplification by Stimulated Emission (Refer Slide Time: 00:37) So, we start today
More informationPHY138Y Nuclear and Radiation
PHY138Y Nuclear and Radiation Professor Tony Key MP401 key@physics.utoronto.ca Question Would you prefer to have music playing in the 6-7 minutes before class while Larry and I set up? A. YES B. NO C.
More informationChapter 37 Early Quantum Theory and Models of the Atom
Chapter 37 Early Quantum Theory and Models of the Atom Units of Chapter 37 37-7 Wave Nature of Matter 37-8 Electron Microscopes 37-9 Early Models of the Atom 37-10 Atomic Spectra: Key to the Structure
More information15. LECTURE 15. I can calculate the dot product of two vectors and interpret its meaning. I can find the projection of one vector onto another one.
5. LECTURE 5 Objectives I can calculate the dot product of two vectors and interpret its meaning. I can find the projection of one vector onto another one. In the last few lectures, we ve learned that
More information1. Why photons? 2. Photons in a vacuum
Photons and Other Messengers 1. Why photons? Ask class: most of our information about the universe comes from photons. What are the reasons for this? Let s compare them with other possible messengers,
More information3 Radioactivity - Spontaneous Nuclear Processes
3 Radioactivity - Spontaneous Nuclear Processes Becquerel was the first to detect radioactivity. In 1896 he was carrying out experiments with fluorescent salts (which contained uranium) and found that
More informationLecture 10 - Moment of Inertia
Lecture 10 - oment of Inertia A Puzzle... Question For any object, there are typically many ways to calculate the moment of inertia I = r 2 dm, usually by doing the integration by considering different
More informationPHYS 1444 Section 004 Lecture #22
PHYS 1444 Section 004 Lecture #22 Monday, April 23, 2012 Dr. Extension of Ampere s Law Gauss Law of Magnetism Maxwell s Equations Production of Electromagnetic Waves Today s homework is #13, due 10pm,
More informationSelected Topics in Mathematical Physics Prof. Balakrishnan Department of Physics Indian Institute of Technology, Madras
Selected Topics in Mathematical Physics Prof. Balakrishnan Department of Physics Indian Institute of Technology, Madras Module - 11 Lecture - 29 Green Function for (Del Squared plus K Squared): Nonrelativistic
More informationPhysics Lecture 6
Physics 3313 - Lecture 6 Monday February 8, 2010 Dr. Andrew Brandt 1. HW1 Due today HW2 weds 2/10 2. Electron+X-rays 3. Black body radiation 4. Compton Effect 5. Pair Production 2/8/10 3313 Andrew Brandt
More informationChapter Four (Interaction of Radiation with Matter)
Al-Mustansiriyah University College of Science Physics Department Fourth Grade Nuclear Physics Dr. Ali A. Ridha Chapter Four (Interaction of Radiation with Matter) Different types of radiation interact
More informationA few thoughts on 100 years of modern physics. Quanta, Quarks, Qubits
A few thoughts on 100 years of modern physics Quanta, Quarks, Qubits Quanta Blackbody radiation and the ultraviolet catastrophe classical physics does not agree with the observed world Planck s idea: atoms
More informationThe Hydrogen Atom According to Bohr
The Hydrogen Atom According to Bohr The atom We ve already talked about how tiny systems behave in strange ways. Now let s s talk about how a more complicated system behaves. The atom! Physics 9 4 Early
More informationUNIT 18 RADIOACTIVITY. Objectives. to be able to use knowledge of electric and magnetic fields to explore the nature of radiation
UNIT 18 RADIOACTIVITY Objectives to be able to use knowledge of electric and magnetic fields to explore the nature of radiation to understand that radioactivity is a statistical process; each unstable
More informationUnits, limits, and symmetries
Units, limits, and symmetries When solving physics problems it s easy to get overwhelmed by the complexity of some of the concepts and equations. It s important to have ways to navigate through these complexities
More information3/29/2010. Structure of the Atom. Knowledge of atoms in 1900 CHAPTER 6. Evidence in 1900 indicated that the atom was not a fundamental unit:
3/9/010 CHAPTER 6 Rutherford Scattering 6.1 The Atomic Models of Thomson and Rutherford 6. Definition of Cross Section 6. Rutherford Scattering 6.3 Structure of the Nucleus The opposite of a correct statement
More informationElectromagnetic Waves
Nicholas J. Giordano www.cengage.com/physics/giordano Chapter 23 Electromagnetic Waves Marilyn Akins, PhD Broome Community College Electromagnetic Theory Theoretical understanding of electricity and magnetism
More informationSpecial Theory of Relativity Prof. Dr. Shiva Prasad Department of Physics Indian Institute of Technology, Bombay
(Refer Slide Time: 00:36) Special Theory of Relativity Prof. Dr. Shiva Prasad Department of Physics Indian Institute of Technology, Bombay Lecture - 7 Examples of Length Contraction and Time Dilation Hello,
More informationis the minimum stopping potential for which the current between the plates reduces to zero.
Module 1 :Quantum Mechanics Chapter 2 : Introduction to Quantum ideas Introduction to Quantum ideas We will now consider some experiments and their implications, which introduce us to quantum ideas. The
More informationHW9 Concepts. Alex Alemi November 1, 2009
HW9 Concepts Alex Alemi November 1, 2009 1 24.28 Capacitor Energy You are told to consider connecting a charged capacitor together with an uncharged one and told to compute (a) the original charge, (b)
More informationLecture 17: Small-Sample Inferences for Normal Populations. Confidence intervals for µ when σ is unknown
Lecture 17: Small-Sample Inferences for Normal Populations Confidence intervals for µ when σ is unknown If the population distribution is normal, then X µ σ/ n has a standard normal distribution. If σ
More informationPhysics 663. Particle Physics Phenomenology. April 23, Physics 663, lecture 4 1
Physics 663 Particle Physics Phenomenology April 23, 2002 Physics 663, lecture 4 1 Detectors Interaction of Charged Particles and Radiation with Matter Ionization loss of charged particles Coulomb scattering
More informationChapter 37 Early Quantum Theory and Models of the Atom. Copyright 2009 Pearson Education, Inc.
Chapter 37 Early Quantum Theory and Models of the Atom Planck s Quantum Hypothesis; Blackbody Radiation Photon Theory of Light and the Photoelectric Effect Energy, Mass, and Momentum of a Photon Compton
More informationEP225 Lecture 31 Quantum Mechanical E ects 1
EP225 Lecture 31 Quantum Mechanical E ects 1 Why the Hydrogen Atom Is Stable In the classical model of the hydrogen atom, an electron revolves around a proton at a radius r = 5:3 10 11 m (Bohr radius)
More informationWeek 8: Stellar winds So far, we have been discussing stars as though they have constant masses throughout their lifetimes. On the other hand, toward
Week 8: Stellar winds So far, we have been discussing stars as though they have constant masses throughout their lifetimes. On the other hand, toward the end of the discussion of what happens for post-main
More informationFLUX OF VECTOR FIELD INTRODUCTION
Chapter 3 GAUSS LAW ntroduction Flux of vector field Solid angle Gauss s Law Symmetry Spherical symmetry Cylindrical symmetry Plane symmetry Superposition of symmetric geometries Motion of point charges
More informationPlanck s Quantum Hypothesis Blackbody Radiation
Planck s Quantum Hypothesis Blackbody Radiation The spectrum of blackbody radiation has been measured(next slide); it is found that the frequency of peak intensity increases linearly with temperature.
More informationSample Question Paper. Class XII. Physics. Time Allowed: 3 Hours Maximum Marks: 70
Sample Question Paper Class XII Physics Time Allowed: 3 Hours Maximum Marks: 70 General Instructions 1. All questions are compulsory. There are 26 questions in all. 2. This question paper has five sections:
More informationAddition of Opacities and Absorption
Addition of Opacities and Absorption If the only way photons could interact was via simple scattering, there would be no blackbodies. We ll go into that in much more detail in the next lecture, but the
More informationUNIT : QUANTUM THEORY AND THE ATOM
Name St.No. Date(YY/MM/DD) / / Section UNIT 102-10: QUANTUM THEORY AND THE ATOM OBJECTIVES Atomic Spectra for Hydrogen, Mercury and Neon. 1. To observe various atomic spectra with a diffraction grating
More informationQuantum Physics and Atomic Models Chapter Questions. 1. How was it determined that cathode rays possessed a negative charge?
Quantum Physics and Atomic Models Chapter Questions 1. How was it determined that cathode rays possessed a negative charge? 2. J. J. Thomson found that cathode rays were really particles, which were subsequently
More informationAdvanced Optical Communications Prof. R. K. Shevgaonkar Department of Electrical Engineering Indian Institute of Technology, Bombay
Advanced Optical Communications Prof. R. K. Shevgaonkar Department of Electrical Engineering Indian Institute of Technology, Bombay Lecture No. # 15 Laser - I In the last lecture, we discussed various
More informationINTRODUCTION. Introduction. Discrete charges: Electric dipole. Continuous charge distributions. Flux of a vector field
Chapter 2 THE ELECTRC FELD ntroduction Discrete charges: Electric dipole Continuous charge distributions Flux of a vector field Flux of an electric field for a spherical Gaussian surface concentric to
More informationChapter 27 Lecture Notes
Chapter 27 Lecture Notes Physics 2424 - Strauss Formulas: λ P T = 2.80 10-3 m K E = nhf = nhc/λ fλ = c hf = K max + W 0 λ = h/p λ - λ = (h/mc)(1 - cosθ) 1/λ = R(1/n 2 f - 1/n 2 i ) Lyman Series n f = 1,
More informationAtomic Models. 1) Students will be able to describe the evolution of atomic models.
Atomic Models 1) Students will be able to describe the evolution of atomic models. 2) Students will be able to describe the role of experimental evidence in changing models of the atom. 3) Students will
More informationNPRE 446: Interaction of Radiation with Matter Homework Assignments
NPRE 446: Interaction of Radiation with Matter Homework Assignments Prof. Y Z Department of Nuclear, Plasma, and Radiological Engineering Department of Materials Science and Engineering Department of Electrical
More informationLECTURE 32: Young's Double-Slit Experiment
Select LEARNING OBJECTIVES: LECTURE 32: Young's Double-Slit Experiment Understand the two models of light; wave model and particle model. Be able to understand the difference between diffraction and interference.
More informationLecture 3f Polar Form (pages )
Lecture 3f Polar Form (pages 399-402) In the previous lecture, we saw that we can visualize a complex number as a point in the complex plane. This turns out to be remarkable useful, but we need to think
More informationEGS: Lab Activities. Virtual Visitor Center at SLAC
EGS Lab Activities (SLAC VVC) http://www2.slac.stanford.edu/vvc/egs/lab/lab.html of 2007-0-8 0: AM Virtual Visitor Center at SLAC EGS: Lab Activities Photons interact with material in many ways, but the
More informationTHE NATURE OF THE ATOM. alpha particle source
chapter THE NATURE OF THE ATOM www.tutor-homework.com (for tutoring, homework help, or help with online classes) Section 30.1 Rutherford Scattering and the Nuclear Atom 1. Which model of atomic structure
More informationPMARIZED LI6HT FUNDAMENTALS AND APPLICATIONS EBWABD COLLETT. Measurement Concepts, Inc. Colts Neck, New Jersey
PMARIZED LI6HT FUNDAMENTALS AND APPLICATIONS EBWABD COLLETT Measurement Concepts, Inc. Colts Neck, New Jersey Marcel Dekker, Inc. New York Basel Hong Kong About the Series Preface A Historical Note iii
More informationQuantum and Atomic Physics - Multiple Choice
PSI AP Physics 2 Name 1. The Cathode Ray Tube experiment is associated with: (A) J. J. Thomson (B) J. S. Townsend (C) M. Plank (D) A. H. Compton 2. The electron charge was measured the first time in: (A)
More informationWaves, Polarization, and Coherence
Waves, Polarization, and Coherence Lectures 5 Biophotonics Jae Gwan Kim jaekim@gist.ac.kr, X 2220 School of Information and Communication Engineering Gwangju Institute of Sciences and Technology Outline
More informationExperiment 4: Charge to mass ratio (e/m) of the electron
Experiment 4: Charge to mass ratio (e/m) of the electron Nate Saffold nas2173@columbia.edu Office Hour: Monday, 5:30PM-6:30PM @ Pupin 1216 INTRO TO EXPERIMENTAL PHYS-LAB 1494/2699 Introduction Our first
More informationPHY-105: Nuclear Reactions in Stars (continued)
PHY-105: Nuclear Reactions in Stars (continued) Recall from last lecture that the nuclear energy generation rate for the PP reactions (that main reaction chains that convert hyogen to helium in stars similar
More informationLECTURE 23 SPECTROSCOPY AND ATOMIC MODELS. Instructor: Kazumi Tolich
LECTURE 23 SPECTROSCOPY AND ATOMIC MODELS Instructor: Kazumi Tolich Lecture 23 2 29.1 Spectroscopy 29.2 Atoms The first nuclear physics experiment Using the nuclear model 29.3 Bohr s model of atomic quantization
More informationChapter 34. Electromagnetic Waves
Chapter 34 Electromagnetic Waves Waves If we wish to talk about electromagnetism or light we must first understand wave motion. If you drop a rock into the water small ripples are seen on the surface of
More informationChemistry Instrumental Analysis Lecture 2. Chem 4631
Chemistry 4631 Instrumental Analysis Lecture 2 Electromagnetic Radiation Can be described by means of a classical sinusoidal wave model. Oscillating electric and magnetic field. (Wave model) wavelength,
More informationDistances in R 3. Last time we figured out the (parametric) equation of a line and the (scalar) equation of a plane:
Distances in R 3 Last time we figured out the (parametric) equation of a line and the (scalar) equation of a plane: Definition: The equation of a line through point P(x 0, y 0, z 0 ) with directional vector
More informationCHAPTER 11 RADIATION 4/13/2017. Outlines. 1. Electric Dipole radiation. 2. Magnetic Dipole Radiation. 3. Point Charge. 4. Synchrotron Radiation
CHAPTER 11 RADIATION Outlines 1. Electric Dipole radiation 2. Magnetic Dipole Radiation 3. Point Charge Lee Chow Department of Physics University of Central Florida Orlando, FL 32816 4. Synchrotron Radiation
More informationLight as a Transverse Wave.
Waves and Superposition (Keating Chapter 21) The ray model for light (i.e. light travels in straight lines) can be used to explain a lot of phenomena (like basic object and image formation and even aberrations)
More informationThe atom cont. +Investigating EM radiation
The atom cont. +Investigating EM radiation Announcements: First midterm is 7:30pm on Sept 26, 2013 Will post a past midterm exam from 2011 today. We are covering Chapter 3 today. (Started on Wednesday)
More informationMITOCW ocw-18_02-f07-lec02_220k
MITOCW ocw-18_02-f07-lec02_220k The following content is provided under a Creative Commons license. Your support will help MIT OpenCourseWare continue to offer high quality educational resources for free.
More informationAtom Model and Relativity
Atom Model and Relativity Kimmo Rouvari September 8, 203 Abstract What is the theoretical explanation for fine structure? What is the mechanism behind relativity? These questions have bothered numerous
More informationASTRO 114 Lecture Okay. We re now gonna continue discussing and conclude discussing the entire
ASTRO 114 Lecture 55 1 Okay. We re now gonna continue discussing and conclude discussing the entire universe. So today we re gonna learn about everything, everything that we know of. There s still a lot
More informationRecall: The Importance of Light
Key Concepts: Lecture 19: Light Light: wave-like behavior Light: particle-like behavior Light: Interaction with matter - Kirchoff s Laws The Wave Nature of Electro-Magnetic Radiation Visible light is just
More information3. Particle-like properties of E&M radiation
3. Particle-like properties of E&M radiation 3.1. Maxwell s equations... Maxwell (1831 1879) studied the following equations a : Gauss s Law of Electricity: E ρ = ε 0 Gauss s Law of Magnetism: B = 0 Faraday
More information4.4 Atomic structure Notes
4.4 Atomic structure Notes Ionising radiation is hazardous but can be very useful. Although radioactivity was discovered over a century ago, it took many nuclear physicists several decades to understand
More informationPhysics 6303 Lecture 5 September 5, 2018
Physics 6303 Lecture 5 September 5, 2018 LAST TIME: Examples, reciprocal or dual basis vectors, metric coefficients (tensor), and a few general comments on tensors. To start this discussion, I will return
More information13.2 NUCLEAR PHYSICS HW/Study Packet
13.2 NUCLEAR PHYSICS HW/Study Packet Required: READ Tsokos, pp 407-412 SL/HL Supplemental: Cutnell and Johnson, pp 652-652, 970-973 DO Questions pp 412-414 #1,3,11 REMEMBER TO. Work through all of the
More informationPhysics 116. Nov 22, Session 32 Models of atoms. R. J. Wilkes
Physics 116 Session 32 Models of atoms Nov 22, 2011 Thomson Rutherford R. J. Wilkes Email: ph116@u.washington.edu Announcements Exam 3 next week (Tuesday, 11/29) Usual format and procedures I ll post example
More informationINTERACTIONS OF RADIATION WITH MATTER
INTERACTIONS OF RADIATION WITH MATTER Renée Dickinson, MS, DABR Medical Physicist University of Washington Medical Center Department of Radiology Diagnostic Physics Section Outline Describe the various
More informationPHYSICS 102N Spring Week 12 Quantum Mechanics and Atoms
PHYSICS 102N Spring 2009 Week 12 Quantum Mechanics and Atoms Quantum Mechanics 1. All objects can be represented by waves describing their propagation through space 2. The wave length is λ=h/p and frequency
More informationA most elegant philosophy about the Theory Of Everything
A most elegant philosophy about the Theory Of Everything Author: Harry Theunissen (pseudonym) Email: htheunissen61@hotmail.com Abstract: Given a simple set of assumptions, this paper gives an elegant explanation
More informationThe Building Blocks of Nature
The Building Blocks of Nature PCES 15.1 Schematic picture of constituents of an atom, & rough length scales. The size quoted for the nucleus here (10-14 m) is too large- a single nucleon has size 10-15
More informationChapter 18. Fundamentals of Spectrophotometry. Properties of Light
Chapter 18 Fundamentals of Spectrophotometry Properties of Light Electromagnetic Radiation energy radiated in the form of a WAVE caused by an electric field interacting with a magnetic field result of
More informationCollege Physics II Lab 5: Equipotential Lines
INTRODUCTION College Physics II Lab 5: Equipotential Lines Peter Rolnick and Taner Edis Spring 2018 Introduction You will learn how to find equipotential lines in a tray of tap water. (Consult section
More information37-6 Watching the electrons (matter waves)
37-6 Watching the electrons (matter waves) 1 testing our proposition: the electrons go either through hole 1 or hole 2 add a very strong light source behind walls between two holes, electrons will scatter
More informationSample Question Paper. Class XII -Physics. (Applicable for March 2016 Examination) Time Allowed: 3 Hours Maximum Marks: 70
Sample Question Paper Class XII -Physics (Applicable for March 2016 Examination) Time Allowed: 3 Hours Maximum Marks: 70 General Instructions 1. All questions are compulsory. There are 26 questions in
More informationPhysics 2D Lecture Slides Lecture 10: Jan 26 th 2004
Brian Wecht, the TA, is away this week. I will substitute for his office hours (in my office 3314 Mayer Hall, discussion and PS session. Pl. give all regrade requests to me this week Quiz 3 is This Friday
More information