1-1 lecture 1: chem 312 introduction class organization §outcomes §grading chart of the nuclides...
TRANSCRIPT
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Lecture 1: CHEM 312 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
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CHEM 312: Introduction• Outcomes for CHEM 312
Understand the fundamentals of radiation science Understand chemical properties in radiation and
radiochemistry Comprehend and evaluate the production of isotopes
and nuclear reactions Comprehend radioactive decay Utilization of nuclear properties in chemistry and
research Investigation of modern topics in radiochemistry
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Grading• Homework Quizzes (10 %)
Weekly quiz based on homework assignment
• Three exams (20 % each) Based on topic covered and homework
• Literature Report (5 %) Written report on literature
• Final Exam (25 %) Based on topics from exams May be oral exam
• Introduce radiochemistry concepts and research
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Outline
Class # Date Topic
1 Monday 28-Aug Chart of the Nuclides, Chap 1. Introductory Concepts
2 Wednesday 30-Aug Chap 1. Introductory Concepts
XXX Monday 04-Sep Labor Day
3 Wednesday 06-Sep Chap 2. Nuclear Properties
4 Monday 11-Sep Chap. 3 Decay Kinetics
5 Wednesday 13-Sep Chap. 3 Decay Kinetics
6 Monday 18-Sep Chap. 3 Decay Kinetics
7 Wednesday 20-Sep Exam 1
8 Monday 25-Sep Chap. 5 Nuclear Forces
9 Wednesday 27-Sep Chap. 6 Nuclear Structure
10 Monday 02-Oct Chap. 7 Alpha Decay
11 Wednesday 04-Oct Chap. 7 Alpha Decay
12 Monday 09-Oct Chap. 8 Beta Decay
13 Wednesday 11-Oct Chap. 9 Gamma Decay
14 Monday 16-Oct Chap. 9 Gamma Decay
15 Wednesday 18-Oct Exam 2
16 Monday 23-Oct Chap. 10 Nuclear Reactions
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Outline
17 Wednesday 25-Oct Chap. 10 Nuclear Reactions
18 Monday 30-Oct Chap. 11 Fission
19 Wednesday 01-Nov Chap. 11 Fission
20 Monday 06-Nov Chap. 4 Radiotracers
21 Wednesday 08-Nov Chap. 12 Cosmochemistry
22 Monday 13-Nov Chap. 13 Analytical applications
23 Wednesday 15-Nov Chap. 14 Reactors and Accelerators
24 Monday 20-Nov Exam 3
25 Wednesday 22-Nov Chap. 15 Transuranium elements
26 Monday 27-Nov Chap. 16 Nuclear Fuel Cycle
27 Wednesday 29-Nov Chap. 17 Interaction of Radiation with Matter
28 Monday 04-Dec Chap. 18 Radiation detectors
29 Wednesday 06-Dec Chap. 19 Radiochemical Techniques in Research
30 Monday 11-Dec 1010 AM: Final Exam
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Chart of the Nuclides
• Presentation of data on nuclides Information on chemical element Nuclide information
Spin and parity (0+ for even-even nuclides) Fission yield
Stable isotope Isotopic abundance Reaction cross sections Mass
• Radioactive isotope Half-life Modes of decay and energies Beta disintegration energies Isomeric states Natural decay series Reaction cross sections
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Chart of the Nuclides
• How many stable isotopes of Ni? • What is the mass and isotopic abundance of
84Sr?• Spin and parity of 201Hg?• Decay modes and decay energies of 212Bi• What are the isotopes in the 235U decay series?• What is the half-life of 176Lu?• What is the half-life of 176Yb
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Chart of Nuclides
• Decay modes Alpha Beta Positron Photon Electron capture Isomeric transition Internal conversion Spontaneous fission Cluster decay
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1. decay (occurs among the heavier elements)
2. decay
3. Positron emission
4. Electron capture
5. Spontaneous fission
Types of Decay
EnergyRnRa 42
22286
22688
EnergyXeI 13154
13153
EnergyNeNa 2210
2211
EnergyMgAl 2612
2613
EnergynRuXeCf 10
10844
14054
25298 4
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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)
Electrons can be excited* Higher energy orbitals* Ionization
Binding energy of electron effects ionization Isotopes
Same Z different N Isobar
Same A (sum of Z and N) Isotone
Same N, different Z Isomer
Nuclide in excited state 99mTc
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Terms and decay modes
• Identify the isomer, isobars, isotones, and isotopes 60mCo, 57Co, 58Co, 57Ni, 57Fe, 59Ni
• Identify the daughter from the decay of the following isotopes 210Po 196Pb 204Bi 209Pb 222At 212Bi 208Pb
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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
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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 Z0 are constants depending on the observed transition.
• K series, Z0 = 1, L series, Z0 = 7.4.
L L
K L
K
(a)
l
2 2 1 1 0
2 2 1 1 0
1 1 0
0
j
5/2 3/2 3/2 1/2 1/2
5/2 3/2 3/2 1/2 1/2
3/2 1/2 1/2
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E(keV)
0,077 0,079 0,151 0,164 0,231
0,728 0,741 0,990 1,056 1,215
5,014 5,360 5,706
35,974
(b)
valeurs de (A;°
) valeurs de (A;°
) valeurs de ( A;°
) L1 2,34723 L2 2,90145 K1 0,35434
L4 2,66587 L1 2,89193 K2 0,40482
L3 2,63521 L 2,98932 K1 0,40026
L2 2,51146 Ll 3,26618
L1 2,68321 K2 0,34608
O
N
M
L
K
)ZZ(A o
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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 3.5517 3.4908 • N1 1.4408 8.6052 • N2 1.2726 9.7426 • N3 1.0449 11.8657 U absorption edges and scattering coefficients
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Fundamentals of x-rays
• X-rays X-ray wavelengths from 1E-5 angstrom to
100 angstromDe-acceleration of high energy electronsElectron transitions from inner orbitals
* Bombardment of metal with high energy electrons
* Secondary x-ray fluorescence by primary x-rays
* Radioactive sources* Synchrotron sources
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Half LivesN/No=e-t
N=Noe- t
=(ln 2)/t1/2
is decay constant
Rate of decay of 131I as a function of time.
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Equation questions
• Calculate decay constant for the following 75Se 74mGa 81Zn
• What percentage of 66As remains after 0.5 seconds
• How long would it take to decay 90 % of 65Zn?• If you have 1 g of 72Se initially, how much
remains in 12 days?
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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
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Fundamental Forces
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Classic and relativistic
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Use of relativistic terms
• relativistic expressions
• photons, neutrinos
• Electrons > 50 keV
• nucleons when the kinetic energy/nucleon exceeds 100 MeV
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Wavelengths and energy
• Planck evaluated minimum from Ext 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
2
h
p/
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Wavelengths
• Photon relationships
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Particle Physics
• fundamental particles of nature and interaction symmetries
• Particles classified as fermions or bosons Fermions obey the Pauli principle
antisymmetric wave functions half-integer spins
* Neutrons, protons and electrons Bosons do not obey Pauli principle
* symmetric wave functions and integer spins Photons
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Particle physics
• Particle groups divided leptons (electron) hadrons (neutron and
proton) hadrons can
interact via the strong interaction
Both can interact with other forces
Fermionic Hadrons comprised of quarks