Wednesday, February 24, 2016

Spring 2016: CHEM 312 Lecture 8 Nuclear Models

This lecture provides information on nuclear force and nuclear models. The strong force is introduced through isospin. A comparison of exchange particles is provided. The use of mirror nuclei to examine the strong force is presented. An overview of nuclear potentials is provided and used to discuss the shell model. States of the shell model and their relationship to magic numbers are discussed. Use of the shell model is determine nuclide spin and parity is presented. The relationship between spin and parity with nuclear deformation is introduced with Nilsson diagrams. Additional information on Nilsson diagrams can be found in the Table of the Isotopes. An introduction of the Fermi model for energetic nuclei is given. 

Sunday, February 21, 2016

Spring 2016: CHEM 312 Lecture 7 Fission

A general overview of nuclear fission is presented.  The probability of fission is described based on developed models including the liquid drop model and shell corrections.  Discussion on spontaneous fission and fissioning isomers is given.  The transition nucleus and fission product distributions are discussed.  The total kinetic energy, mass distribution, and charge distribution during fission are presented. Changes in fission product distribution with parent properties are introduced. Delayed neutrons from fission and their role in reactors are given. Proton induced fission is introduced. 

Monday, February 15, 2016

Spring 2016: 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.

Thursday, February 11, 2016

Spring 2016: 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.

Tuesday, February 9, 2016

Spring 2016: CHEM 312 Quiz 1

Assigned:  9-Feb-2016
Due:15-Feb-2016
2nd Due Date: 18-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 15-Feb-2016. The answers will be posted on 16-Feb-2016. 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 on Tuesday 16 February at 1000 in the 1st floor conference room of the HRC.