501503747
This presentation is the property of its rightful owner.
Sponsored Links
1 / 38

Nuclear Physics at BAU nuclear.bau.jo/ This course nuclear.bau.jo/Reactors PowerPoint PPT Presentation


  • 108 Views
  • Uploaded on
  • Presentation posted in: General

501503747 Nuclear Reactors. Nuclear Physics at BAU http://nuclear.bau.edu.jo/ This course http://nuclear.bau.edu.jo/Reactors Prerequisites Nuclear and Radiation Physics 742 http://nuclear.bau.edu.jo/nuclear-radiation Advanced Statistical Mechanics 761. General subjects to be covered.

Download Presentation

Nuclear Physics at BAU nuclear.bau.jo/ This course nuclear.bau.jo/Reactors

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Nuclear physics at bau nuclear bau jo this course nuclear bau jo reactors

501503747

Nuclear Reactors

  • Nuclear Physics at BAU

  • http://nuclear.bau.edu.jo/

  • This course

  • http://nuclear.bau.edu.jo/Reactors

  • Prerequisites

  • Nuclear and Radiation Physics 742

  • http://nuclear.bau.edu.jo/nuclear-radiation

  • Advanced Statistical Mechanics 761

Nuclear Reactors, BAU, First Semester, 2007-2008

(Saed Dababneh).


Nuclear physics at bau nuclear bau jo this course nuclear bau jo reactors

General subjects to be covered

  • Review of relevant studied material in nuclear physics.

  •        Concepts in neutron physics.

  •       The relevant physics related to nuclear technology:

    • Fission chain reaction.

    •   Neutron diffusion and moderation.

    • Heat removal from nuclear reactors.

    • Isotope separation.

    •   …

  •      Components of nuclear reactors.

  •       Nuclear reactor fuels and fuel cycles.

  • •       Nuclear reactor theory.

  • •       Basic concepts of radiation protection and nuclear safety, shielding and waste disposal.

  • •       Issues and prospects of nuclear power today and in the future.

  • Nuclear Reactors, BAU, 1st Semester, 2007-2008

    (Saed Dababneh).


    Nuclear physics at bau nuclear bau jo this course nuclear bau jo reactors

    Grading

    Review Test05%

    Mid-term Exam20%

    Projects, quizzes and HWs25%

    Final Exam50%

    • Homeworks are due after one week unless otherwise announced.

    • Remarks or questions marked in red without being announced as homeworks should be also seriously considered!

    • Some tasks can (or should) be sent by email:

    • [email protected]

    Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh).


    Nuclear physics at bau nuclear bau jo this course nuclear bau jo reactors

    Review Test

    Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh).


    Nuclear physics at bau nuclear bau jo this course nuclear bau jo reactors

    Projects

    • Consider nuclear fuel cycles with emphasis on front ends.

      • Work as a team. Divide and organize the job among you.

      • Try to explore local applicability.

      • Due date (for written version): December 5th.

      • Presentation: Will be scheduled later.

  • Other small projects will be announced in class.

  • Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh).


    Nuclear physics at bau nuclear bau jo this course nuclear bau jo reactors

    Nuclear Reaction Energetics (revisited)

    • Conservation Laws

    • Charge, Baryon number, total energy, linear momentum, angular momentum, parity, (isospin??)…….

    b

    pb

    gs

    a

    pa

    X

    +ve Q-value  exoergic reaction.

    -ve Q-value  endoergic reaction.

    pY

    Y

    Stationary X ??

    +ve Q-value  reaction possible if Ta 0.

    -ve Q-value  reaction not possible if Ta 0. (Is Ta > |Q| sufficient?).

    Conservation of momentum ……

    Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh).


    Nuclear physics at bau nuclear bau jo this course nuclear bau jo reactors

    Nuclear Reaction Energetics (revisited)

    HW 1

    • Conservation of momentum.

    • We usually do not detect Y.

    • Show that:

    • The threshold energy (for Ta): (the condition occurs for  = 0º).

    • +ve Q-value  reaction possible if Ta 0.

    • Coulomb barriers…….!!!

    • -ve Q-value  reaction possible if Ta> TTh.

    double valued !?

    solve for Q

    Q < 0

    Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh).


    Nuclear physics at bau nuclear bau jo this course nuclear bau jo reactors

    Nuclear Reaction Energetics (revisited)

    HW 1(continued)

    • The double valued situation occurs between TTh and the upper limit Ta\.

    • Double-valued in a forward cone.

    Q < 0

    Discuss the elasticand inelastic scatteringof neutronsusing these relations.

    Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh).


    Nuclear physics at bau nuclear bau jo this course nuclear bau jo reactors

    Nuclear Reaction Energetics (revisited)

    Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh).


    Nuclear physics at bau nuclear bau jo this course nuclear bau jo reactors

    Nuclear Reaction Energetics (revisited)

    What about neutron induced reactions?

    Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh).


    Nuclear physics at bau nuclear bau jo this course nuclear bau jo reactors

    Nuclear Reaction Energetics (revisited)

    What about neutron induced reactions?

    Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh).


    Nuclear physics at bau nuclear bau jo this course nuclear bau jo reactors

    Nuclear Reaction Energetics (revisited)

    What about neutron induced reactions?

    Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh).


    Nuclear physics at bau nuclear bau jo this course nuclear bau jo reactors

    Nuclear Reaction Energetics (revisited)

    • If the reaction reaches excited states of Y

    58Ni(,p)61Cu

    even less ….

    less proton energy

    Highest proton energy

    See Figures 11.4 in Krane

    What about neutron induced reactions?

    Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh).


    Nuclear physics at bau nuclear bau jo this course nuclear bau jo reactors

    Neutron Interactions (revisited)

    • Chadwick’s discovery.

    • Neutrons interact with nuclei, not with atoms. (Exceptions).

    • Recall from Nuclear Physics 742:

      • Inelastic scattering (n,n\). Q = -E* Inelastic gammas. Threshold?

      • Elastic scattering (n,n). Q = ?? (Potential and CN). Neutron moderation?

      • Radiative capture (n,). Q = ?? Capture gammas.

      • (n,), (n,p). Q = ?? Absorption Reactions.

      • (n,2n), (n,3n) Q = ?? Energetic neutrons on heavy water can easily eject the loosely bound neutron.

      • Fission. (n,f).

    • HW 2 Examples of such exo- and endo-thermic reactions with Q calculations.

    Non-elastic

    Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh).


    Nuclear physics at bau nuclear bau jo this course nuclear bau jo reactors

    Neutron Scattering (revisited)

    • Elastic or inelastic.

    • Analogous to diffraction.

    • Alternating maxima and minima.

    • First maximum at

    • Minimum not at zero (sharp edge of the nucleus??)

    • Clear for neutrons.

    • Protons? High energy, large angles. Why?

    • Inelastic  Excited states, energy, X-section and spin-parity.

    Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh).


    Nuclear physics at bau nuclear bau jo this course nuclear bau jo reactors

    Reaction Cross Section (revisited)

    • Probability.

    • Projectile a will more probably hit target X if area is larger.

    • Classically:  = (Ra + RX)2.

    • Classical  = ??? (in b)n+ 1H, n + 238U, 238U + 238U

    • Quantum mechanically:  =  2.

    • Coulomb and centrifugal barriers  energy dependence of .

    • What about neutrons?

    • Nature of force:

    • Strong:15N(p,)12C ~ 0.5 b at Ep = 2 MeV.

    • Electromagnetic:3He(,)7Be ~ 10-6 b at E = 2 MeV.

    • Weak:p(p,e+)D ~ 10-20 b at Ep = 2 MeV.

    • Experimental challenges to measure low X-sections..

    Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh).


    Nuclear physics at bau nuclear bau jo this course nuclear bau jo reactors

    Reaction Cross Section (Simple terms)

    A (Area of the beam!!)

    |v|

    X

    Position of a neutron 1 s before arriving at target

    Target with N atoms.cm-3 or NAX atoms.

    Monoenergetic neutrons of speed v (cm.s-1) and density n (cm-3)

    Volume = vA

    containing nvA neutrons that hit the “whole” target in 1 s.

    Beam Intensity InvA/A = nv (cm-2s-1)

    Number of neutrons interacting with target per second

     I, A, X and N

    = t I N A X

    Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh).


    Nuclear physics at bau nuclear bau jo this course nuclear bau jo reactors

    Reaction Cross Section (Simple terms)

    • Number of neutrons interacting with target per second

    • = t I N A X

    • Number of interactions with a single nucleus per second

    • = t IInterpretation and units of .

    • nvA= IA neutrons strike the target per second, of these

    • tI neutrons interact with any single nucleus. Thus,

    • measures the probability for a neutron to hit a nucleus.

    Study examples in Lamarsh

    Total cross section

    Total number of nuclei in the target

    Effective cross-sectional area of the nucleus.

    Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh).


    Nuclear physics at bau nuclear bau jo this course nuclear bau jo reactors

    Reaction Cross Section (Simple terms)

    Number of neutrons interacting with target per second

    = t I N A X

    Number of interactions per cm3 per second (Collision Density)

    Ft= t I N = I t

    t= N t

    Study examples in Lamarsh

    Total cross section

    Volume of the target

    Macroscopic total cross section.

    Probability per unit path length.

    Attenuation not moderation !

    Mean free path

    Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh).


    Nuclear physics at bau nuclear bau jo this course nuclear bau jo reactors

    Reaction Cross Section (Simple terms)

    Homogeneous Mixture

    Molecule xmyn Nx=mN, Ny=nN

    given that events at x and y are independent.

    Study examples in Lamarsh

    Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh).


    Nuclear physics at bau nuclear bau jo this course nuclear bau jo reactors

    Reaction Cross Section (revisited)

    Look for b

    Detector for particle “b”

    d

    Ia

    “b” particles / s

    ,

    cm2

    “X“ target Nuclei / cm2

    “a” particles / s

    Typical nucleus (R=6 fm): geometrical R2  1 b.

    Typical : <b to >106 b.

    Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh).


    Nuclear physics at bau nuclear bau jo this course nuclear bau jo reactors

    Reaction Cross Section (revisited)

    Many different quantities are called

    “cross section”.

    Krane Table 11.1

    Angular distribution

    Units … !

    “Differential” cross section

    (,) or ( )

    or “cross section” …!!

    Doubly differential

    t for all “b” particles.

    Energy state in “Y”

    Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh).


    Nuclear physics at bau nuclear bau jo this course nuclear bau jo reactors

    Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh).


    Nuclear physics at bau nuclear bau jo this course nuclear bau jo reactors

    n-TOF

    CERN

    Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh).


    Nuclear physics at bau nuclear bau jo this course nuclear bau jo reactors

    Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh).


    Nuclear physics at bau nuclear bau jo this course nuclear bau jo reactors

    Different Features (revisited)

    1/v

    Fast neutrons should be moderated.

    235U thermal cross sections

    fission  584 b.

    scattering  9 b.

    radiative capture  97 b.

    Fission Barriers

    Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh).


    Nuclear physics at bau nuclear bau jo this course nuclear bau jo reactors

    Neutron Induced Reactions (revisited)

    X(n,b)Y

    b(Q+En)

    n(En)

    Probability to penetrate the potential barrier

    Po(Ethermal) = 1

    P>o(Ethermal) = 0

    For thermal neutrons

    Q >> En

    b(Q)  constant

    Non-resonant

    Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh).


    Nuclear physics at bau nuclear bau jo this course nuclear bau jo reactors

    Neutron Induced Reactions (revisited)

    Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh).


    Nuclear physics at bau nuclear bau jo this course nuclear bau jo reactors

    Statistical Factor (revisited)

    HW 3

    Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh).


    Nuclear physics at bau nuclear bau jo this course nuclear bau jo reactors

    Resonance Reactions (revisited)

    J

    Ex

    a + X  Y + bQ > 0

    b + Y  X + aQ < 0

    Excited

    State

    Entrance Channel

    a + X

    Exit

    Channel

    b + Y

    Inverse Reaction

    Compound Nucleus C*

    Identical

    particles

    • Nature of force(s).

    • Time-reversal invariance.

    Statistical

    Factor ()

    QM

    HW 4

    Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh).


    Nuclear physics at bau nuclear bau jo this course nuclear bau jo reactors

    Resonance Reactions (revisited)

    Projectile

    Projectile

    Target

    Target

    Q-value

    Q-value

    Q + ER = Er

    E = E + Q - Eex

    Direct Capture

    (all energies)

    Resonant Capture

    (selected energies with large X-section)

    Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh).


    Nuclear physics at bau nuclear bau jo this course nuclear bau jo reactors

    Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh).


    Nuclear physics at bau nuclear bau jo this course nuclear bau jo reactors

    Resonance Reactions (revisited)

    Damped Oscillator

    Oscillator strength

    Damping

    factor

    eigenfrequency

    Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh).


    Nuclear physics at bau nuclear bau jo this course nuclear bau jo reactors

    Resonance Reactions (revisited)

    Breit-Wigner formula

    • All quantities in CM system

    • Only for isolated resonances.

    Reaction

    Elastic scattering

    Usually a>> b.

    HW 5When does R take its maximum value?

    Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh).


    Nuclear physics at bau nuclear bau jo this course nuclear bau jo reactors

    Resonance Reactions (revisited)

    Exit

    Channel

    b + Y

    Ja + JX + l = J

    (-1)l(Ja) (JX) = (J)

    (-1)l = (J) Natural parity.

    J

    Ex

    Excited

    State

    Entrance Channel

    a + X

    Compound Nucleus C*

    Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh).


    Nuclear physics at bau nuclear bau jo this course nuclear bau jo reactors

    Resonance Reactions (revisited)

    What is the “Resonance Strength” …?

    What is its significance?

    In what units is it measured?

    Charged particle

    radiative capture (a,)

    (What about neutrons?)

    Cross section

    EC

    a

    

    Energy

    Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh).


    Nuclear physics at bau nuclear bau jo this course nuclear bau jo reactors

    Neutron Resonance Reactions (revisited)

    Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh).


    Nuclear physics at bau nuclear bau jo this course nuclear bau jo reactors

    Neutron Activation Analysis (revisited)

    (Z,A) + n (Z, A+1)

    -

     (-delayed -ray)

    (Z+1, A+1)

    http://ie.lbl.gov/naa !

    Project 1

    Nuclear Reactors, BAU, 1st Semester, 2007-2008 (Saed Dababneh).


  • Login