Monday, February 13, 2017

Spring 2017 CHEM 312: Lecture 6 Gamma Decay

Gamma decay is described in two lectures. The first lecture covers the fundamentals of gamma decay and second lecture describes Moessbauer spectroscopy. Different methods to find data on gamma decay yields for decay of isotopes are presented. The energetics involved in gamma decay are provided. This includes recoil from gamma, which is exploited in Moessbauer spectroscopy. Decay types in gamma transitions are explained, focusing on electromagnetic basis for the gamma emission. Transition probabilities and internal conversions inherent to gamma decay are covered. Isotope examples for internal conversion electrons are given. Angular correlations in gamma decay are described with an experimental example provided. The use of gamma decay in Moessbauer spectroscopy is discussed. Part 1 is 34 minutes and part 2 is 28 minutes. The lecture is assigned 14-Feb-17 and PDF Quiz 6 is due 21-Feb-17.

Monday, February 6, 2017

Spring 2017 CHEM 312: Exam 1

Exam 1
Assigned: 7-Feb-2017
2nd Due Date: 16-Feb-2016

Use the chart of the nuclides, table of the isotopes, and/or data from the web links to answer the following questions. Please feel free to contact me via the blog with questions. The quiz is due on 13-Feb-2017. The answers will be posted on 14-Feb-20176. Changes can be made to the quiz after reviewing the answers. You will need to provide your work for any changes in a separate document. All changed questions will be worth a maximum of 50 % of the point total. A skype meeting of the quiz will be held.  The exam covers:

Lecture 1: Introduction, Chart of the Nuclides
Lecture 2: Nuclear Properties
Lecture 3: Decay Kinetics

Sunday, February 5, 2017

Spring 2017 CHEM 312: Lecture 5 Beta Decay

Beta decay is presented in this lecture. The neutrino hypothesis and its relationship with beta decay is discussed. A review of Q value calculations for beta decay is provided. The importance of spin and parity, and how it can be used to assess beta decay, is discussed. Modeling beta decay through the weak force is provided. The impact of Coulomb interactions on positron and electron spectral shape is presented. The use of Kurie plots in understanding beta decay is introduced. Selection rules in beta decay and beta transitions are explained. Calculating logft and its relation to spin and parity are presented. Double beta decay is discussed. The lecture time is 47 minutes.  The lecture is assigned 9-Feb-17 and the PDF quiz is due 19-Feb-17.

Sunday, January 29, 2017

Spring 2017 CHEM 312: Lecture 4 Alpha Decay

This lecture discusses alpha decay in radionuclides. Theories on alpha decay are presented. Systematics and energetics involved in alpha decay are presented. The correlation between Q value and decay energy is described. The Geiger Nuttall relationship is provided, described, and utilized in a model for alpha decay. Tunneling is also exploited to described alpha decay, coupling energy and half-life. Gamow calculations are shown to reflect the Geiger Nuttall relationship. Hindered alpha decay is discussed. Hindered alpha decay is employed to described nuclear properties. Hinderance factors are described, along with how they are calculated and where they can be found. Proton and other charged particle emission are presented. The lecture time is 46 minutes.   The lecture is assigned 2-Feb-17 and PDF Quiz 4 due 7-Feb-17.

Thursday, January 26, 2017

Spring 2017 CHEM 312: Lecture 3 Decay Kinetics

This lecture covers the fundamental equations that describe the decay of radionuclides. Basic equations and their utility are presented. Equations for mixtures, equilibrium, and branching of radionuclides are covered. Examples are provided for error evaluation from counts, activity determination, evaluation of half life, and lifetime of isotopes. Discussion of natural radiation and dating are given. Examples are provided for dating from 238U, 14C, and the Oklo reactor. The lecture time for part 1 is 43 minutes. Part 2 is 60 minutes.  The lecture is assigned 26-Jan-17.  The PDF Quiz 3 is due 5-Feb-17.

Thursday, January 19, 2017

Spring 2017 CHEM 312: Lecture 2 Nuclear Properties

A discussion on systematics of nuclear properties are presented.  Mass, mass excess, and mass distribution within the nucleus is presented.   Mass excess data are used to calculate energies in decays.  Equations for determining nuclear radii are provided.  Models that are used to describe the stability of nuclei are introduced.  Nuclear shapes and structures are introduced. The lecture time is 47 minutes. The supplemental lecture on the Q value calculator is around 3 minutes.  The lectures are available in Powerpoint audio and MP4 format from the CHEM 312 youtube channel.  The lecture is assigned: 19-Jan-17 and PDF Quiz 2 is due 29-Jan-17.

Monday, January 16, 2017

Spring 2017 CHEM 312: Lecture 1 Introduction and Chart of the Nuclides

The class outcomes, expectations, and grading are explained.  A history of radioelement discovery and radiation research is presented. The Chart of the Nuclides and Table of the Isotopes are discussed and used.  Atomic properties, nuclear nomenclature, X-rays, types of decays and physical forces are introduced. Part one viewing time 38 minutes, part 2 viewing time 42 minutes.  The PDF quiz 1 is assigned 17-Jan-17 and due 24-Jan-17.