PPT-Lecture 4: Mathematics of Decay and Units of Radioactivity

Unit I the Physics of Nuclear Medicine From Researchers Find Cancer in Ancient Egyptian Mummy The Cosmos News Retrieved 27 Aug 2012 from httpwwwcosmostvorg201201researchersfindcancerinancienthtml . University of Nebraska. SPRING 2009. 17 April 2009. What is the mass defect for iodine 131? . Given: . 1. H atom mass = 1.007825 . amu. , neutron mass = 1.008665 . amu. , . 131. I mass = 130.90612 . Sections 32-1 . – 32-9. Physics 1161: . . Lecture . 25. Radioactivity. Spontaneous emission of radiation from the nucleus of an unstable isotope.. Marie Curie. 1867 - 1934. Wilhelm Roentgen. 1845 - 1923. Pierre Curie was already a famous scientist before he married Marie Sklodowska in 1895.  This famous couple did not only find true love, they also discovered radium and polonium.  For their groundbreaking research in radioactivity, the couple were awarded the 1903 Nobel Prize in physics.  It was Marie Curie who coined the term "radioactivity", and in her honor, the 1910 Radiology Congress chose the curie as the basic unit of radioactivity.  Pierre died from being run over by a horse drawn wagon, but Marie continued their research, and was eventually awarded a second Nobel Prize, the 1911 prize for Chemistry.  She died in 1934, suffering from pernicious anemia which had undoubtedly been the result of years of radiation exposure.. http://www.npl.co.uk/educate-explore/factsheets/ionising-radiation/. We’re surrounded by radioactivity everyday.. Some sources are natural and some sources are anthropogenic (human made.). We’re going to investigate some sources of natural radioactivity found in the environment.. Individual risk model. Introduction. . For insurer there is essential to know the property of the distribution of future claims. We are trying to calculate the distribution of claim amount if there are given certain distribution. DEFINE. the term decay heat.. Given the operating conditions of a reactor core and the necessary formulas, . CALCULATE . the core decay heat generation.. DESCRIBE. two categories of methods for removing decay heat from a reactor core.. Lecture . 9. Absolute Dating of the Earth. Major Concepts. The discovery of radioactivity in the early 1900’s and the recognition that . radioactive deca. y . (a statistical event) . occurs at a constant average rate for particular unstable isotopes has provided a means of determining the absolute ages of earth materials.  . The decay rate.  . Lorentz Invariant Phase Space. The decay rate.  . The decay rate.  . Decay amplitude. Describes the interactions during the decay.. The Feynman diagrams. The Feynman diagrams. Lecture 9. Absolute Dating of the Earth. Major Concepts. The discovery of radioactivity in the early 1900’s and the recognition that . radioactive decay . (a statistical event) occurs at a constant average rate for particular unstable isotopes has provided a means of determining the absolute ages of earth materials. 24.1 Nuclear Radiation. 24.2 Radioactive Decay (includes decay rates & radiochemical dating). 24.3 Nuclear Reactions (Transmutation. Part only). 24.4 Applications & Effects of Nuclear Reactions (except for radiation dose and intensity/distance). How can anyone know the age of something millions of years ago?. Scientists for many years did not have a way to determine the age of fossils, rocks or even our planet. . Isotopes . Atoms of the same element can have different numbers of neutrons; the different possible versions of each element are called . Rate of Radioactive decay with units. Geiger-Muller Counter. An atom is composed of positively charged nucleus that is surrounded by. negatively charged electrons.. The number of electrons is equal to the number of protons = Atomic Number. Rate of Radioactive decay with units. Geiger-Muller Counter. An atom is composed of positively charged nucleus that is surrounded by. negatively charged electrons.. The number of electrons is equal to the number of protons = Atomic Number. Where: . A . = Activity after some time t.. A. o. . = Original activity of the sample.. t . = Decay time . λ = the radioactive decay constant equal to . The half-life equation can be also used for activity, simply by replacing the number of atoms .