slide1 l.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Nuclear Reactions PowerPoint Presentation
Download Presentation
Nuclear Reactions

Loading in 2 Seconds...

play fullscreen
1 / 18

Nuclear Reactions - PowerPoint PPT Presentation


  • 173 Views
  • Uploaded on

Nuclear Reactions. Sample. Nuclear Reactions. Nuclear Reactions. Nuclear Reactions. Nuclear Reactions. If the reaction reaches excited states of Y. 58 Ni( ,p) 61 Cu. even less …. less proton energy. Highest proton energy. See Figures 11.4 in Krane. Nuclear Reactions.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Nuclear Reactions' - ikia


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
slide1

Nuclear Reactions

Sample

Nuclear and Radiation Physics, BAU, First Semester, 2007-2008 (Saed Dababneh).

slide2

Nuclear Reactions

Nuclear and Radiation Physics, BAU, First Semester, 2007-2008 (Saed Dababneh).

slide3

Nuclear Reactions

Nuclear and Radiation Physics, BAU, First Semester, 2007-2008 (Saed Dababneh).

slide4

Nuclear Reactions

Nuclear and Radiation Physics, BAU, First Semester, 2007-2008 (Saed Dababneh).

slide5

Nuclear Reactions

  • 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

Nuclear and Radiation Physics, BAU, First Semester, 2007-2008 (Saed Dababneh).

slide6

Nuclear Reactions

  • Neutron scattering
  • Inelastic Q = -Eex (=-E*).
  • Elastic Q = 0.

HW 32

Discuss the elastic and inelastic scattering of neutrons using the relations you derived in HW 31.

Nuclear and Radiation Physics, BAU, First Semester, 2007-2008 (Saed Dababneh).

slide7

Nuclear Reactions

  • Categorization of Nuclear Reactions
  • According to: bombarding particle, bombarding energy, target, reaction product, reaction mechanism.
  • Bombarding particle:
    • Charged particle reactions. [ (p,n) (p,) (,) heavy ion reactions ].
    • Neutron reactions. [ (n,) (n,p) ….. ].
    • Photonuclear reactions. [ (,n) (,p) … ].
    • Electron induced reactions………….
  • Bombarding energy:
    • Thermal.
    • Epithermal.
    • Slow.
    • Fast.
    • Low energy charged particles.
    • High energy charged particles.

?

Neutrons.

Nuclear and Radiation Physics, BAU, First Semester, 2007-2008 (Saed Dababneh).

slide8

Nuclear Reactions

  • Targets:
    • Light nuclei (A < 40).
    • Medium weight nuclei (40 < A < 150).
    • Heavy nuclei (A > 150).
  • Reaction products:
    • Scattering. Elastic 14N(p,p)14N

Inelastic 14N(p,p/)14N*

    • Radiative capture.
    • Fission and fusion.
    • Spallation.
    • …..
  • Reaction mechanism:
    • Direct reactions.
    • Compound nucleus reactions.
  • More in what follows ….
  • What is a transfer reaction….?????

Pickup

Resonant

Stripping

Non-resonant

Nuclear and Radiation Physics, BAU, First Semester, 2007-2008 (Saed Dababneh).

slide9

Reaction Cross Section(s) (Introduction)

  • Probability.
  • Projectile a will more probably hit target X if area is larger.
  • Classically:  = (Ra + RX)2.
  • Classical  = ??? (in b)1H + 1H, 1H + 238U, 238U + 238U
  • Quantum mechanically:  =  2.
  • Coulomb and centrifugal barriers  energy dependence of .
  • 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..

HW 33

Nuclear and Radiation Physics, BAU, First Semester, 2007-2008 (Saed Dababneh).

slide10

Reaction Cross Section(s) (Introduction)

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 and Radiation Physics, BAU, First Semester, 2007-2008 (Saed Dababneh).

slide11

Reaction Cross Section(s) (Introduction)

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 and Radiation Physics, BAU, First Semester, 2007-2008 (Saed Dababneh).

slide12

Coulomb Scattering

  • Elastic or inelastic.
  • Elastic  Rutherford scattering.
  • At any distance:

V = 0

Ta = ½mvo2

l = mvob

vmin

vo

rmin

b

d

Nuclear and Radiation Physics, BAU, First Semester, 2007-2008 (Saed Dababneh).

No dependence on 

slide13

Coulomb Scattering

Nuclear and Radiation Physics, BAU, First Semester, 2007-2008 (Saed Dababneh).

slide14

Coulomb Scattering

b

< b > 

dbd

n target nuclei / cm3

x target thickness (thin).

nx  target nuclei / cm2

HW 34

Show that

and hence

b

Rutherford cross section

Nuclear and Radiation Physics, BAU, First Semester, 2007-2008 (Saed Dababneh).

slide15

Coulomb Scattering

Study Fig. 11.10 (a,b,c,d)

in Krane

See also Fig. 11.11 in Krane.

HW 35

Show that the fraction of incident alpha particles scattered at backward angles from a 2 m gold foil is 7.48x10-5.

Nuclear and Radiation Physics, BAU, First Semester, 2007-2008 (Saed Dababneh).

slide16

Coulomb Scattering

  • Elastic  Rutherford scattering.
  • Inelastic Coulomb excitation.

See the corresponding alpha spectrum of Fig. 11.12 in Krane.

Nuclear and Radiation Physics, BAU, First Semester, 2007-2008 (Saed Dababneh).

slide17

Coulomb Scattering

Nuclear and Radiation Physics, BAU, First Semester, 2007-2008 (Saed Dababneh).

slide18

Nuclear Scattering

  • 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 and Radiation Physics, BAU, First Semester, 2007-2008 (Saed Dababneh).