Chapter 10 - Nuclear 10 - Nuclear Physics The Nucleus Radioactive Decay Nuclear Fission Nuclear Fusion Chapter 10 - Nuclear Physics The release of atomic energy

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Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionChapter 10 - Nuclear PhysicsThe release of atomic energyhas not created a newproblem. It has merely mademore urgent the necessity ofsolving an existing one. -Albert EinsteinDavid J. StarlingPenn State HazletonPHYS 214Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionThe NucleusErnest Rutherford proposed and discovered thenucleus in 1911.Alpha particles are positively charged helium nuclei 4He.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionThe NucleusErnest Rutherford proposed and discovered thenucleus in 1911.Alpha particles are positively charged helium nuclei 4He.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionThe NucleusTheir scattering angle theory matchedpredictions!Geiger and Marsden conducted the experiments with Radongas.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionThe NucleusTheir scattering angle theory matchedpredictions!Geiger and Marsden conducted the experiments with Radongas.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionThe NucleusProtons (Z) and Neutrons (N) combine to give themass number (A) of the atom.Note how the masses are not whole number multiples ofHydrogen.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionThe NucleusProtons (Z) and Neutrons (N) combine to give themass number (A) of the atom.Note how the masses are not whole number multiples ofHydrogen.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionThe NucleusAtoms tend to have more neutrons than protons,and can have multiple stable isotopes.Bismuth (Z = 83) is the largest stable nucleus.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionThe NucleusAtoms tend to have more neutrons than protons,and can have multiple stable isotopes.Bismuth (Z = 83) is the largest stable nucleus.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionThe NucleusStable nuclides have different abundances;radionuclides have different half-lives.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionThe NucleusThe radius of nuclides can be roughlyapproximated.r = r0 A1/3with r0 = 1.2 fm and A the mass number.This only applies to spherical nuclides and not to unstablehalo nuclides (e.g., 113 Li).Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionThe NucleusThe radius of nuclides can be roughlyapproximated.r = r0 A1/3with r0 = 1.2 fm and A the mass number.This only applies to spherical nuclides and not to unstablehalo nuclides (e.g., 113 Li).Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionThe NucleusAtomic masses are reported in atomic mass unitswith Carbon-12 defined to be 12 u.1 u = 1.660538 1027 kgmp = 1.672623 1027 kgmn = 1.674929 1027 kgTherefore, the mass number of an atom and its atomic massare very similar (e.g., 197Au has a mass of 196.966522 u).Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionThe NucleusAtomic masses are reported in atomic mass unitswith Carbon-12 defined to be 12 u.1 u = 1.660538 1027 kgmp = 1.672623 1027 kgmn = 1.674929 1027 kgTherefore, the mass number of an atom and its atomic massare very similar (e.g., 197Au has a mass of 196.966522 u).Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionThe NucleusAtomic masses are reported in atomic mass unitswith Carbon-12 defined to be 12 u.1 u = 1.660538 1027 kgmp = 1.672623 1027 kgmn = 1.674929 1027 kgTherefore, the mass number of an atom and its atomic massare very similar (e.g., 197Au has a mass of 196.966522 u).Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionThe NucleusIt takes energy to pull protons and neutrons apart;therefore, they lose energy when they cometogether.This change in energy is equivalent to a change in mass (viaE = mc2).Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionThe NucleusIt takes energy to pull protons and neutrons apart;therefore, they lose energy when they cometogether.This change in energy is equivalent to a change in mass (viaE = mc2).Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionThe NucleusIt takes energy to pull protons and neutrons apart;therefore, they lose energy when they cometogether.This change in energy is equivalent to a change in mass (viaE = mc2).Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionThe NucleusThe binding energy is justEb =imic2 Mc2 > 0.The mass excess is M A.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionThe NucleusThe binding energy is justEb =imic2 Mc2 > 0.The mass excess is M A.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionThe NucleusThe binding energy is justEb =imic2 Mc2 > 0.The mass excess is M A.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionThe NucleusOnce formed, nuclides have energy levels similarto the electrons.However, much more energy is required to excite thenucleus.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionThe NucleusOnce formed, nuclides have energy levels similarto the electrons.However, much more energy is required to excite thenucleus.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionThe NucleusOnce formed, nuclides have energy levels similarto the electrons.However, much more energy is required to excite thenucleus.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionThe NucleusLecture Question 10.1Which statement is true about the forces inside an atom?(a) Gravity holds electrons, while the strong nuclear forceholds nuclei together.(b) Gravity holds electrons in their orbits and nucleitogether.(c) Gravity holds electrons, while the electromagneticforce holds nuclei together.(d) The strong nuclear force holds electrons, while theelectromagnetic force holds nuclei together.(e) The electromagnetic force holds electrons, while thestrong nuclear force holds nuclei together.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionRadioactive DecayUnstable nuclei decay into other nuclei. For asample of N particles, the rate is proportional toN with decay constant .dNdt= NSolving for N:dNN= dt NN0dNN= t0dtlnNN0= tN = N0etChapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionRadioactive DecayUnstable nuclei decay into other nuclei. For asample of N particles, the rate is proportional toN with decay constant .dNdt= NSolving for N:dNN= dt NN0dNN= t0dtlnNN0= tN = N0etChapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionRadioactive DecayUnstable nuclei decay into other nuclei. For asample of N particles, the rate is proportional toN with decay constant .dNdt= NSolving for N:dNN= dt NN0dNN= t0dtlnNN0= tN = N0etChapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionRadioactive DecayUnstable nuclei decay into other nuclei. For asample of N particles, the rate is proportional toN with decay constant .dNdt= NSolving for N:dNN= dt NN0dNN= t0dtlnNN0= tN = N0etChapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionRadioactive DecayUnstable nuclei decay into other nuclei. For asample of N particles, the rate is proportional toN with decay constant .dNdt= NSolving for N:dNN= dt NN0dNN= t0dtlnNN0= tN = N0etChapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionRadioactive DecayThe number of nuclei decays exponentially.1 becquerel = 1 Bq = 1 decay per second1 curie = 1 Ci = 3.7 1010 BqChapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionRadioactive DecayThe number of nuclei decays exponentially.1 becquerel = 1 Bq = 1 decay per second1 curie = 1 Ci = 3.7 1010 BqChapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionRadioactive DecayThe number of nuclei decays exponentially.1 becquerel = 1 Bq = 1 decay per second1 curie = 1 Ci = 3.7 1010 BqChapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionRadioactive DecayThe decay rate is minus the derivative of N.R = dNdt= N0et = R0etThe half-life is the time to reduce the nucleinumber (or decay rate) by 1/2.R = R0eT1/2 = R0/2T1/2 = ln 2/ = ln 2The mean life time = 1/ is when N has been reduced toN0/e.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionRadioactive DecayThe decay rate is minus the derivative of N.R = dNdt= N0et = R0etThe half-life is the time to reduce the nucleinumber (or decay rate) by 1/2.R = R0eT1/2 = R0/2T1/2 = ln 2/ = ln 2The mean life time = 1/ is when N has been reduced toN0/e.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionRadioactive DecayThe decay rate is minus the derivative of N.R = dNdt= N0et = R0etThe half-life is the time to reduce the nucleinumber (or decay rate) by 1/2.R = R0eT1/2 = R0/2T1/2 = ln 2/ = ln 2The mean life time = 1/ is when N has been reduced toN0/e.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionRadioactive DecayAlpha decay is when a heavy nucleus emits analpha particle (i.e., 4He nucleus).The alpha particle is bound within the 238U nucleus but cantunnel out with some small probability, leaving behind a234Th nuclues.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionRadioactive DecayAlpha decay is when a heavy nucleus emits analpha particle (i.e., 4He nucleus).The alpha particle is bound within the 238U nucleus but cantunnel out with some small probability, leaving behind a234Th nuclues.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionRadioactive DecayBeta decay is when a proton or neutron decaysinto the other, emitting an electron or positron topreserve charge.3215P 3216S + e + 6429Cu 6428Ni + e+ + The half life for these reactions is 14.3 d and 12.7 h,respectively. The very low mass particle is a neutrino.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionRadioactive DecayBeta decay is when a proton or neutron decaysinto the other, emitting an electron or positron topreserve charge.3215P 3216S + e + 6429Cu 6428Ni + e+ + The half life for these reactions is 14.3 d and 12.7 h,respectively. The very low mass particle is a neutrino.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionRadioactive DecaySince two particles share the energy of betaemission, the positron/electron can have a rangeof energies.For beta decay of copper to nickel, the most probablepositron emission energy is 0.15 MeV.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionRadioactive DecaySince two particles share the energy of betaemission, the positron/electron can have a rangeof energies.For beta decay of copper to nickel, the most probablepositron emission energy is 0.15 MeV.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionRadioactive DecayNeutrinos interact very weakly with matter and solarge detectors are required to see even the mostmassive supernova events.This data is from the Super-Kamiokande detector in Japan,1000 m underground, holding 50,000 tons of ultra-purewater.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionRadioactive DecayNeutrinos interact very weakly with matter and solarge detectors are required to see even the mostmassive supernova events.This data is from the Super-Kamiokande detector in Japan,1000 m underground, holding 50,000 tons of ultra-purewater.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionRadioactive DecayUnstable nuclides decay toward stable ones overtime; the nuclidic chart (abbreviated) helpsunderstand how this works.Radioactive nuclides transform through alpha decay, betadecay, emission of protons or neutrons, or fission intodaughter particles.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionRadioactive DecayUnstable nuclides decay toward stable ones overtime; the nuclidic chart (abbreviated) helpsunderstand how this works.Radioactive nuclides transform through alpha decay, betadecay, emission of protons or neutrons, or fission intodaughter particles.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionRadioactive DecayUsing the half-life of radioactive decay andmeasurements of various nuclides, we can datethe age of objects.Radiocarbon dating places the age of the Dead Sea Scrollsfrom the West Bank at around 2,000 years old.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionRadioactive DecayUsing the half-life of radioactive decay andmeasurements of various nuclides, we can datethe age of objects.Radiocarbon dating places the age of the Dead Sea Scrollsfrom the West Bank at around 2,000 years old.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionRadioactive DecayThere are two ways to measure radiation doses.I Absorbed DoseI Independent of type of radiationI 1 gray = 1 Gy = 1 J/kgI 1 Gy = 100 radI Dose EquivalentI Accounts for type of radiation for biological purposesI RBE factors (relative biological effectiveness)I 1 sievert = 1 SvI 1 Sv = 100 remPersonal monitoring devices measure Dose Equivalent.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionRadioactive DecayThere are two ways to measure radiation doses.I Absorbed DoseI Independent of type of radiationI 1 gray = 1 Gy = 1 J/kgI 1 Gy = 100 radI Dose EquivalentI Accounts for type of radiation for biological purposesI RBE factors (relative biological effectiveness)I 1 sievert = 1 SvI 1 Sv = 100 remPersonal monitoring devices measure Dose Equivalent.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionRadioactive DecayThere are two ways to measure radiation doses.I Absorbed DoseI Independent of type of radiationI 1 gray = 1 Gy = 1 J/kgI 1 Gy = 100 radI Dose EquivalentI Accounts for type of radiation for biological purposesI RBE factors (relative biological effectiveness)I 1 sievert = 1 SvI 1 Sv = 100 remPersonal monitoring devices measure Dose Equivalent.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionRadioactive DecayWhy does the nucleus behave like this?I Collective ModelI nucleons bounce around at randomI short mean free pathI helps describe nuclear reactionsI Independent Particle ModelI nucleons exist in stable quantum statesI explains why some nuclei show closed-shell effectsI collisions only occur for open quantum statesI Combined ModelI combines features of previous modelsI shell of outside nucleons occupy quantized statesI these nucleons interact with core and create tidalwavesChapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionRadioactive DecayWhy does the nucleus behave like this?I Collective ModelI nucleons bounce around at randomI short mean free pathI helps describe nuclear reactionsI Independent Particle ModelI nucleons exist in stable quantum statesI explains why some nuclei show closed-shell effectsI collisions only occur for open quantum statesI Combined ModelI combines features of previous modelsI shell of outside nucleons occupy quantized statesI these nucleons interact with core and create tidalwavesChapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionRadioactive DecayWhy does the nucleus behave like this?I Collective ModelI nucleons bounce around at randomI short mean free pathI helps describe nuclear reactionsI Independent Particle ModelI nucleons exist in stable quantum statesI explains why some nuclei show closed-shell effectsI collisions only occur for open quantum statesI Combined ModelI combines features of previous modelsI shell of outside nucleons occupy quantized statesI these nucleons interact with core and create tidalwavesChapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionRadioactive DecayLecture Question 10.2When bismuth 211Bi undergoes alpha decay, what nucleus isproduced in addition to a helium nucleus?(a) 207Bi(b) 207Tl(c) 209Au(d) 211Au(e) 209TlChapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionNuclear FissionEnergy can be generated in a variety of ways.Nuclear reactions tend to release much more energy.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionNuclear FissionEnergy can be generated in a variety of ways.Nuclear reactions tend to release much more energy.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionNuclear FissionFission happens when a species becomesunstable.Energy is released by fast moving neutrons.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionNuclear FissionFission happens when a species becomesunstable.Energy is released by fast moving neutrons.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionNuclear FissionAs the nucleus distorts (r), the nuclides potentialenergy varies.Once the distortion grows beyond 5 fm, the nuclearreaction occurs.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionNuclear FissionAs the nucleus distorts (r), the nuclides potentialenergy varies.Once the distortion grows beyond 5 fm, the nuclearreaction occurs.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionNuclear FissionWhen a neutron is captured, does the addedenergy exceed the potential barrier?Only certain radionuclides are fissionable by neutroncapture.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionNuclear FissionWhen a neutron is captured, does the addedenergy exceed the potential barrier?Only certain radionuclides are fissionable by neutroncapture.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionNuclear FissionWhen a radionuclide undergoes fission, itsfragments can vary.The most probable mass numbers are around A 95 andA 140.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionNuclear FissionWhen a radionuclide undergoes fission, itsfragments can vary.The most probable mass numbers are around A 95 andA 140.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionNuclear FissionFor 236U, when a neutron is ejected into aneighbor, we may get:235U + n +236U 140Xe +94Sr + 2nBut 140Xe and 94Sr are unstable and will decay further:14054 Xe14 s 14055 Cs64 s 14056 Ba13 d 14057 La40 h 14058 Ce9438Sr75 s 9439Y19 m 9440ZrChapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionNuclear FissionFor 236U, when a neutron is ejected into aneighbor, we may get:235U + n +236U 140Xe +94Sr + 2nBut 140Xe and 94Sr are unstable and will decay further:14054 Xe14 s 14055 Cs64 s 14056 Ba13 d 14057 La40 h 14058 Ce9438Sr75 s 9439Y19 m 9440ZrChapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionNuclear FissionTo calculate the energy released, you compare thebinding energies before and after the reaction hascompleted.Q =jEben,jNj iEben,iNiI Eben,i is the binding energy per nucleon for species iI Ni is the number of nucleons of species iI Primes indicate after reactionI Sum i is over initial nuclides (e.g., 236U)I Sum j is over final products (e.g., 140Xe and 94Sr)Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionNuclear FissionTo calculate the energy released, you compare thebinding energies before and after the reaction hascompleted.Q =jEben,jNj iEben,iNiI Eben,i is the binding energy per nucleon for species iI Ni is the number of nucleons of species iI Primes indicate after reactionI Sum i is over initial nuclides (e.g., 236U)I Sum j is over final products (e.g., 140Xe and 94Sr)Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionNuclear FissionConsider previous example:236U 140Xe + 94Sr + 2nQ =jEben,jNj iEben,iNi= (E140Xe 140 + E94Sr 94) (E236U 236)= 8.29 140 + 8.59 94 7.59 236= 177 MeVBinding energies: Uranium-236 (7.59 MeV), Xenon-140(8.29 MeV) and Strontium-94 (8.59 MeV).Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionNuclear FissionConsider previous example:236U 140Xe + 94Sr + 2nQ =jEben,jNj iEben,iNi= (E140Xe 140 + E94Sr 94) (E236U 236)= 8.29 140 + 8.59 94 7.59 236= 177 MeVBinding energies: Uranium-236 (7.59 MeV), Xenon-140(8.29 MeV) and Strontium-94 (8.59 MeV).Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionNuclear FissionConsider previous example:236U 140Xe + 94Sr + 2nQ =jEben,jNj iEben,iNi= (E140Xe 140 + E94Sr 94) (E236U 236)= 8.29 140 + 8.59 94 7.59 236= 177 MeVBinding energies: Uranium-236 (7.59 MeV), Xenon-140(8.29 MeV) and Strontium-94 (8.59 MeV).Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionNuclear FissionConsider previous example:236U 140Xe + 94Sr + 2nQ =jEben,jNj iEben,iNi= (E140Xe 140 + E94Sr 94) (E236U 236)= 8.29 140 + 8.59 94 7.59 236= 177 MeVBinding energies: Uranium-236 (7.59 MeV), Xenon-140(8.29 MeV) and Strontium-94 (8.59 MeV).Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionNuclear FissionConsider previous example:236U 140Xe + 94Sr + 2nQ =jEben,jNj iEben,iNi= (E140Xe 140 + E94Sr 94) (E236U 236)= 8.29 140 + 8.59 94 7.59 236= 177 MeVBinding energies: Uranium-236 (7.59 MeV), Xenon-140(8.29 MeV) and Strontium-94 (8.59 MeV).Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionNuclear FissionA nuclear reactor must operate in a stableconfiguration by managing neutron number andspeed.For fission, fast neutrons are not as effective as slow,thermal neutrons.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionNuclear FissionA nuclear reactor must operate in a stableconfiguration by managing neutron number andspeed.For fission, fast neutrons are not as effective as slow,thermal neutrons.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionNuclear FissionThe first man-made reactor was built on a squashcourt at the University of Chicago during WorldWar II.The fuel was lumps of Uranium embedded in blocks ofgraphite.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionNuclear FissionThe first man-made reactor was built on a squashcourt at the University of Chicago during WorldWar II.The fuel was lumps of Uranium embedded in blocks ofgraphite.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionNuclear FissionSo you spit a bunch of atoms. Now what?You heat water!Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionNuclear FissionSo you spit a bunch of atoms. Now what?You heat water!Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionNuclear FissionLecture Question 10.3How many neutrons are released in the following reaction:23592 U +10n 8838Sr + 13654 Xe + __ 10n(a) 1(b) 3(c) 6(d) 8(e) 12Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionNuclear FusionNuclear fusion combines lighter atoms (with lowEben) to form heavier atoms (with higherEben).Combining hydrogen into helium is how our sun producesso much energy.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionNuclear FusionNuclear fusion combines lighter atoms (with lowEben) to form heavier atoms (with higherEben).Combining hydrogen into helium is how our sun producesso much energy.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionNuclear FusionThermonuclear fusion is when the temperature ofbulk matter is high enough for atoms to overcomeCoulomb repulsion during collisions.In the sun, hydrogen above 3 keV has an appreciable chanceto fuse.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionNuclear FusionThermonuclear fusion is when the temperature ofbulk matter is high enough for atoms to overcomeCoulomb repulsion during collisions.In the sun, hydrogen above 3 keV has an appreciable chanceto fuse.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionNuclear FusionIn the sun, six 1H atoms and an electron canproduce one 4He atom, two 1H atoms, six photonsand two neutrinos.This proton-proton chain produces 26.7 MeV total.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionNuclear FusionIn the sun, six 1H atoms and an electron canproduce one 4He atom, two 1H atoms, six photonsand two neutrinos.This proton-proton chain produces 26.7 MeV total.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionNuclear FusionWhen a star burns most of its hydrogen, it eitherbegins to fuse Helium to create heavier elements,or begins to contract and die.For very massive stars (e.g., Sanduleak), this death canresult in a supernova followed by a neutron star, pulsar,black hole or total disintegration.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionNuclear FusionWhen a star burns most of its hydrogen, it eitherbegins to fuse Helium to create heavier elements,or begins to contract and die.For very massive stars (e.g., Sanduleak), this death canresult in a supernova followed by a neutron star, pulsar,black hole or total disintegration.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionNuclear FusionA controlled thermonuclear fusion reaction ispossible using one of the following chains:2H + 2H +3.27 MeV 3He + n2H + 2H +4.03 MeV 3H + 1H2H + 3H +17.59 MeV 4He + nRequirements:I High densityI High temperatureI Long confinement timeChapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionNuclear FusionA controlled thermonuclear fusion reaction ispossible using one of the following chains:2H + 2H +3.27 MeV 3He + n2H + 2H +4.03 MeV 3H + 1H2H + 3H +17.59 MeV 4He + nRequirements:I High densityI High temperatureI Long confinement timeChapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionNuclear FusionNuclear fusion has two main research paths.Magnetic confinement of hot plasma, and laser confinementof fuel pellets.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionNuclear FusionNuclear fusion has two main research paths.Magnetic confinement of hot plasma, and laser confinementof fuel pellets.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionNuclear FusionDeuterium (2H) and tritium (3H) occur naturallyin abundance and can be harvested from seawater.Formed into pellets, they can be fused via laser confinement.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionNuclear FusionDeuterium (2H) and tritium (3H) occur naturallyin abundance and can be harvested from seawater.Formed into pellets, they can be fused via laser confinement.Chapter 10 - NuclearPhysicsThe NucleusRadioactive DecayNuclear FissionNuclear FusionNuclear FusionLecture Question 10.4Consider the following nuclear fusion reaction and identifyparticle X.21H +31H 42He + X(a) a photon(b) a proton(c) a neutron(d) a positron(e) an electronThe NucleusRadioactive DecayNuclear FissionNuclear Fusion

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