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1-1 Lecture 1: RDCH 702 Introduction Class organization §Outcomes §Grading Chart of the nuclides §Description and use of chart §Data Radiochemistry introduction.

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Presentation on theme: "1-1 Lecture 1: RDCH 702 Introduction Class organization §Outcomes §Grading Chart of the nuclides §Description and use of chart §Data Radiochemistry introduction."— Presentation transcript:

1 1-1 Lecture 1: RDCH 702 Introduction Class organization §Outcomes §Grading Chart of the nuclides §Description and use of chart §Data Radiochemistry introduction §Atomic properties §Nuclear nomenclature §X-rays §Types of decays §Forces

2 1-2 RDCH 702: Introduction Outcomes for RDCH 702 §Understand chemical properties in radiation and radiochemistry §Use and application of chemical kinetics and thermodynamics to evaluate radionuclide speciation §Understand the influence of radiolysis on the chemistry of radioisotopes §Understand and evaluate radioisotope production §Evaluate and compare radiochemical separations §Utilization of radioisotope nuclear properties in evaluating chemical behavior §Use and explain the application of radionuclides in research §Discuss and understand ongoing radiochemistry research

3 1-3 Grading Homework (25 %) §Weekly homework questions §Develop tools for research (spreadsheets) Two exams (30 % each) §Oral exam §30 minutes each à1 st exam on question from course information à2 nd exam on literature Classroom participation (15 %) §Bring chart of the nuclides! Class developed to assist and compliment research activities

4 1-4 Chart of the Nuclides Presentation of data on nuclides §Information on chemical element §Nuclide information àSpin and parity (0 + for even-even nuclides) àFission yield §Stable isotope àIsotopic abundance àReaction cross sections àMass Radioactive isotope §Half-life §Modes of decay and energies §Beta disintegration energies §Isomeric states §Natural decay series §Reaction cross sections

5 1-5 Chart of Nuclides Decay modes §Alpha §Beta §Positron §Photon §Electron capture §Isomeric transition §Internal conversion §Spontaneous fission §Cluster decay

6 1-6 Introduction Radiochemistry §Chemistry of the radioactive isotopes and elements §Utilization of nuclear properties in evaluating and understanding chemistry §Intersection of chart of the nuclides and periodic table Atom §Z and N in nucleus (10 -14 m) §Electron interaction with nucleus basis of chemical properties (10 -10 m) àElectrons can be excited *Higher energy orbitals *Ionization ØBinding energy of electron effects ionization §Isotopes àSame Z different N §Isobar àSame A (sum of Z and N) §Isotone àSame N, different Z §Isomer àNuclide in excited state à 99m Tc

7 1-7 X-rays Electron from a lower level is removed §electrons of the higher levels can come to occupy resulting vacancy §energy is returned to the external medium as electromagnetic radiation radiation called an X-ray §discovered by Roentgen in 1895 §In studying x-rays radiation emitted by uranium ores Becquerel et. al. (P. and M. Curie) discovered radioactivity in 1896

8 1-8 X-rays Removal of K shell electrons §Electrons coming from the higher levels will emit photons while falling to this K shell  series of rays (frequency or wavelength ) are noted as K , K , K   If the removed electrons are from the L shell, noted as L , L , L  In 1913 Moseley studied these frequencies, showing that: where Z is the atomic number and, A and Z 0 are constants depending on the observed transition. K series, Z 0 = 1, L series, Z 0 = 7.4.

9 1-9

10 1-10 Absorption Spectra Edge keV A K 115.6061 0.1072 L-I 21.7574 0.5698 L-II 20.9476 0.5919 L-III 17.1663 0.7223 M1 5.5480 2.2348 M2 5.1822 2.3925 M3 4.3034 2.8811 M4 3.7276 3.3261 M5 3.55173.4908 N1 1.4408 8.6052 N2 1.2726 9.7426 N3 1.0449 11.8657 U absorption edges and scattering coefficients

11 1-11 Fundamentals of x-rays X-rays §X-ray wavelengths from 1E-5 angstrom to 100 angstrom àDe-acceleration of high energy electrons àElectron transitions from inner orbitals *Bombardment of metal with high energy electrons *Secondary x-ray fluorescence by primary x-rays *Radioactive sources *Synchrotron sources

12 1-12 1.  decay (occurs among the heavier elements) 2.  decay 3. Positron emission 4. Electron capture 5. Spontaneous fission Types of Decay

13 1-13 Half Lives for the condition: N/N o =1/2=e - t N=N o e - t =(ln 2)/t 1/2 Rate of decay of 131 I as a function of time. http://genchem.chem.wisc.edu/sstutorial/FunChem.htm

14 1-14 Forces in nature Four fundamental forces in nature § All interactions in the universe are the result of these forces Gravity §Weakest force §most significant when the interacting objects are massive, such as planets, stars, etc. Weak interaction §Beta decay Electromagnetic force §Most observable interactions Strong interaction §Nuclear properties

15 1-15 Fundamental Forces

16 1-16 Classic and relativistic

17 1-17 Use of relativistic terms relativistic expressions photons, neutrinos Electrons > 50 keV nucleons when the kinetic energy/nucleon exceeds 100 MeV

18 1-18 Wavelengths and energy Planck evaluated minimum from  Ex  t when he studied the radiation emitted by a black body at a given temperature Quantum called Planck’s constant h (h = 6.6 10 -34 J.s).  radiation conveys energy E in the form of quanta E = h  the frequency of the emitted radiation Based on the wave mechanics worked out by de Broglie  = h/p  is the wavelength associated with any moving particle with the momentum p

19 1-19 Wavelengths Photon relationships

20 1-20 Particle Physics fundamental particles of nature and interaction symmetries Particles classified as fermions or bosons §Fermions obey the Pauli principle àantisymmetric wave functions àhalf-integer spins *Neutrons, protons and electrons àBosons do not obey Pauli principle *symmetric wave functions and integer spins ØPhotons

21 1-21

22 1-22 Particle physics Particle groups divided §leptons (electron) §hadrons (neutron and proton) àhadrons can interact via the strong interaction àBoth can interact with other forces àFermionic Hadrons comprised of quarks


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