PHY 712 Electrodynamics

MWF 10-10:50 PM Online http://www.wfu.edu/~natalie/s21phy712/

Instructor: Natalie Holzwarth Office:300 OPL e-mail:natalie@wfu.edu



Course schedule for Spring 2021

(Preliminary schedule -- subject to frequent adjustment.)
Lecture date
JDJ Reading
Topic
HW
Due date
1 Wed: 01/27/2021 Chap. 1 & Appen. Introduction, units and Poisson equation #1 01/29/2021
2 Fri: 01/29/2021 Chap. 1 Electrostatic energy calculations #2 02/01/2021
3 Mon: 02/01/2021 Chap. 1 & 2 Electrostatic potentials and fields #3 02/03/2021
4 Wed: 02/03/2021 Chap. 1 - 3 Poisson's equation in 2 and 3 dimensions #4 02/05/2021
5 Fri: 02/05/2021 Chap. 1 - 3 Brief introduction to numerical methods #5 02/08/2021
6 Mon: 02/08/2021 Chap. 2 & 3 Image charge constructions #6 02/10/2021
7 Wed: 02/10/2021 Chap. 2 & 3 Cylindrical and spherical geometries
8 Fri: 02/12/2021 Chap. 3 & 4 Spherical geometry and multipole moments #7 02/15/2021
9 Mon: 02/15/2021 Chap. 4 Dipoles and Dielectrics #8 02/19/2021
10 Wed: 02/17/2021 Chap. 4 Dipoles and Dielectrics
11 Fri: 02/19/2021 Chap. 4 Polarization and Dielectrics #9 02/24/2021
12 Mon: 02/22/2021 Chap. 5 Magnetostatics #10 02/26/2021
13 Wed: 02/24/2021 Chap. 5 Magnetic dipoles and hyperfine interaction #11 03/01/2021
14 Fri: 02/26/2021 Chap. 5 Magnetic dipoles and dipolar fields
15 Mon: 03/01/2021 Chap. 6 Maxwell's Equations #12 03/08/2021
16 Wed: 03/03/2021 Chap. 6 Electromagnetic energy and forces
17 Fri: 03/05/2021 Chap. 7 Electromagnetic plane waves
18 Mon: 03/08/2021 Chap. 7 Electromagnetic plane waves #13 03/10/2021
19 Wed: 03/10/2021 Chap. 7 Optical effects of refractive indices #14 03/12/2021
20 Fri: 03/12/2021 Chap. 1-7 Review
Mon: 03/15/2021 No class APS March Meeting Take Home Exam
Wed: 03/17/2021 No class APS March Meeting Take Home Exam
Fri: 03/19/2021 No class APS March Meeting Take Home Exam
21 Mon: 03/22/2021 Chap. 8 EM waves in wave guides
22 Wed: 03/24/2021 Chap. 9 Radiation from localized oscillating sources #15 03/26/2021
23 Fri: 03/26/2021 Chap. 9 Radiation from oscillating sources #16 03/29/2021
24 Mon: 03/29/2021 Chap. 9 & 10 Radiation and scattering #17 03/31/2021
25 Wed: 03/31/2021 Chap. 11 Special Theory of Relativity #18 04/05/2021
26 Fri: 04/02/2021 Chap. 11 Special Theory of Relativity
27 Mon: 04/05/2021 Chap. 11 Special Theory of Relativity #19 04/09/2021
Wed: 04/07/2021 No class Holiday
28 Fri: 04/09/2021 Chap. 14 Radiation from accelerating charged particles #20 04/12/2021
29 Mon: 04/12/2021 Chap. 14 Synchrotron radiation #21 04/14/2021
30 Wed: 04/14/2021 Chap. 14 Synchrotron radiation #22 04/19/2021
31 Fri: 04/16/2021 Chap. 15 Radiation from collisions of charged particles #23 04/21/2021
32 Mon: 04/19/2021 Chap. 15 Radiation from collisions of charged particles
33 Wed: 04/21/2021 Chap. 13 Cherenkov radiation
34 Fri: 04/23/2021 Special topic: E & M aspects of superconductivity
35 Mon: 04/26/2021 Special topic: Overview of some optical properties of materials
36 Wed: 04/28/2021 Review
37 Fri: 04/30/2021 Review
Mon: 05/03/2021 Presentations I
Wed: 05/05/2021 Presentations II


PHY 712 -- Assignment #1

January 27, 2021

Read Chapters I and 1 and Appendix 1 in Jackson.

  1. Jackson Problem #1.5. Be careful to take into account the behavior of Φ(r) for r-->0.

PHY 712 -- Assignment #2

January 29, 2021

Continue reading Chap. 1 in Jackson.

  1. Using the Ewald summation methods developed in class, find the electrostatic interaction energy of a NaCl lattice having a cubic lattice constant a. Check that your result does not depend of the Ewald parameter η. You are welcome to copy (and modify) the maple file used in class. A FORTRAN code is also available upon request.


PHY 712 -- Assignment #4

February 4, 2021

Continue reading Chap. 1 in Jackson.

  1. For the two-dimensional rectangular system discussed in the lecture notes, work out the analytic form of the electrostatic potential Φ(x,y) for the two examples given in the lecture for 0 ≤ x ≤ a and 0 ≤ y ≤ b.

    Example 1: ρ(x,y)= ρ0 sin(πx/a) sin(πy/b)

    Example 2: ρ(x,y)= ρ0.



PHY 712 -- Assignment #6

February 8, 2021

Continue reading Chap. 2 in Jackson.

  1. Eq. 2.5 was derived as the surface change density on a sphere of radius a due to a charge q placed at a radius y > a outside the sphere. Determine the total surface charge on the sphere surface.
  2. Now consider the same system except assume y < a representing the charge q being placed inside the sphere. What is the surface charge density and the total surface charge in this case?

PHY 712 -- Assignment #7

February 12, 2021

Complete reading Chapter 3 and start Chapter 4 in Jackson .

  1. Consider the charge density of an electron bound to a proton in a hydrogen atom -- ρ(r) = (1/πa03) e-2r/a0, where a0 denotes the Bohr radius. Find the electrostatic potential Φ(r) associated with ρ(r). Compare your result to HW#1.

PHY 712 -- Assignment #8

February 15, 2021

Continue reading Chapter 4 in Jackson .

  1. Find the monopole, dipole, and quadrupole moments of the charge distribution shown in the figure in problem 4.1(b) of Jackson. You can use either the Cartesian or spherical polar forms for the moments as you prefer.

PHY 712 -- Assignment #9

February 19, 2021

Finish reading Chapter 4 in Jackson .

  1. Work problem 4.9(a) in Jackson. It is probably most convenient to use a coordinate system with the origin at the center of the dielectric sphere.

PHY 712 -- Assignment #10

February 22, 2021

Start reading Chapter 5 in Jackson .

  1. Consider an infinitely long cylindrical wire with radius a, oriented along the z axis. There is a steady uniform current inside the wire. Specifically, in terms of r the radial parameter of the cylindrical coordinates of the system the current density is J(r)=J0 , where J0 is a constant vector along the z-axis, for ra and zero otherwise.
    1. Find the vector potential (A) for all r.
    2. Find the magnetic flux field (B) for all r.

PHY 712 -- Assignment #11

February 24, 2021

Finish reading Chapter 5 in Jackson .

  1. Work problem 5.13 in Jackson.


PHY 712 -- Assignment #13

March 8, 2021

Continue reading Chapter 7 in Jackson .

  1. Consider the reflectivity of a plane polarized electromagnetic wave incident from air (n=1) on a material with refractive index n'=1.5 at an angle of incidence i, Plot the reflectance

    R(i)=|E"0/E0|2

    as a function of i for 0 ≤ i ≤ 90 deg for both cases of polarization of (E0 in the plane of incidence or perpendicular to the plane of incidence). What is the qualitative difference between the two cases?

PHY 712 -- Assignment #14

March 10, 2020

Finish reading Chapter 7 in Jackson .

  1. Work problem 7.22 (a) in Jackson.

PHY 712 -- Assignment #15

March 24, 2021

Start reading Chapters 9 in Jackson .

  1. Work problem 9.10(b) in Jackson.


PHY 712 -- Assignment #17

March 29, 2021

Finish reading Chapters 9 and 10 in Jackson .

  1. Work problem 9.16(a) in Jackson. Note that you can use an approach similar to that discussed in Section 9.4 of the textbook, replacing the "center-fed" antenna with the given antenna configuration.

PHY 712 -- Assignment #18

March 31, 2021

Begin reading Chapter 11 in Jackson .

  1. Derive the relationships between the component of the electric and magnetic field components E1, E2, E3, B1, B2, and B3 as measured in the stationary frame of reference and the components E'1, E'2, E'3, B'1, B'2, and B'3 measured in the moving frame of reference. Note that the reverse relationships are given in Eq. 11.148.

PHY 712 -- Assignment #19

April 05, 2021

Continue reading Chapter 11 in Jackson .

  1. Supply some of the intermediate steps for deriving the E and B fields resulting from a particle of charge q moving along the x-axis at constant speed v, measured at a point a distance b along the y-axis.

PHY 712 -- Assignment #20

April 9, 2021

Start reading Chap. 14 in Jackson .

  1. Consider an electron moving at constant speed βc ≈ c in a circular trajectory of radius ρ. Its total energy is E= γ m c2. Determine the ratio of the energy lost during one full cycle to its total energy. Evaluate the expression for an electron with total energy of 200 GeV in a synchroton of radius ρ=103 m. (Note: the original statement of the problem had the electron energy of 400 GeV.)

PHY 712 -- Assignment #21

April 12, 2021

Continue reading Chap. 14 in Jackson . This problem is designed to demonstrate Parseval's theorem using the definitions given in the lecture notes and on Page 674 in Jackson. We will use the example

A(t)=K e-(t/T)2,

where K and T are positive constants.

  1. Find the Fourier transform of A(t).
  2. Evaluate the integral of the squared modulus of A(t) between -∞ ≤ t ≤ ∞.
  3. Evaluate the integral of the squared modulus of the Fourier transform of A(t) between -∞ ≤ ω ≤ ∞.

PHY 712 -- Assignment #22

April 12, 2021

Complete reading Chap. 14 in Jackson . In class, we showed how the synchotron radiation spectrum is scaled by the critical frequency ωc or critical energy Ec= ℏωc. Using the intensity formula for radiation in the parallel plane at θ=0, for a beam with Ec=10 GeV, estimate the intensity relative to peak intensity for the following types of radiation (noting your choice of wavelength for each range)

  1. Infrared
  2. Visable
  3. Xray

PHY 712 -- Assignment #23

April 16, 2021

Finish reading Chap. 14 and start Chap. 15 in Jackson .

  1. Derive the Compton formula given on page 696 of Jackson.


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Last modfied: Saturday, 23-Jan-2021 18:03:56 EST