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**Neutron-induced Reactions**

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 and Radiation Physics, BAU, 1st Semester, (Saed Dababneh).

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**Neutron-induced Reactions**

Nuclear and Radiation Physics, BAU, 1st Semester, (Saed Dababneh).

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**Nuclear and Radiation Physics, BAU, 1st Semester, 2006-2007 (Saed Dababneh).**

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**Neutron-induced Reactions**

n-TOF CERN Nuclear and Radiation Physics, BAU, 1st Semester, (Saed Dababneh).

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**Nuclear and Radiation Physics, BAU, 1st Semester, 2006-2007 (Saed Dababneh).**

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**Neutron-induced Reactions**

n_TOF CERN Nuclear and Radiation Physics, BAU, 1st Semester, (Saed Dababneh).

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**Neutron-induced Reactions**

Nuclear and Radiation Physics, BAU, 1st Semester, (Saed Dababneh).

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**Charged Particle Reactions**

What is the Gamow Peak? Nuclear Radius Nuclear and Radiation Physics, BAU, 1st Semester, (Saed Dababneh).

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**Charged Particle Reactions**

Electron Screening Nuclear and Radiation Physics, BAU, 1st Semester, (Saed Dababneh).

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**Charged Particle Reactions**

e2 = 1.44x10-12 keV.m Tunneling probability: In numerical units: For -ray emission: Sommerfeld parameter Gamow factor Multipolarity Nuclear and Radiation Physics, BAU, 1st Semester, (Saed Dababneh).

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**Charged Particle Reactions**

Nuclear (or astrophysical) S-factor Nuclear and Radiation Physics, BAU, 1st Semester, (Saed Dababneh).

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**Charged Particle Reactions**

EC = ?? Nuclear and Radiation Physics, BAU, 1st Semester, (Saed Dababneh).

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**Resonance Reactions E t**

CN particle emission E E > spacing between virtual states continuum. (Lower part larger spacing isolated resonances). D bound states -emission E isolated states. Nuclear and Radiation Physics, BAU, 1st Semester, (Saed Dababneh).

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**Resonance Reactions a + X Y + b Q > 0 b + Y X + a Q < 0**

J Ex a + X Y + b Q > 0 b + Y X + a Q < 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 30 Nuclear and Radiation Physics, BAU, 1st Semester, (Saed Dababneh).

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**(selected energies with large X-section)**

Resonance Reactions 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 and Radiation Physics, BAU, 1st Semester, (Saed Dababneh).

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**Nuclear and Radiation Physics, BAU, 1st Semester, 2006-2007 (Saed Dababneh).**

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**Resonance Reactions HW 31**

Nuclear and Radiation Physics, BAU, 1st Semester, (Saed Dababneh).

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**Resonance Reactions Damped Oscillator Oscillator strength Damping**

factor eigenfrequency Nuclear and Radiation Physics, BAU, 1st Semester, (Saed Dababneh).

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**Resonance Reactions Breit-Wigner formula All quantities in CM system**

Only for isolated resonances. Reaction Elastic scattering Usually a >> b. HW 32 When does R take its maximum value? Nuclear and Radiation Physics, BAU, 1st Semester, (Saed Dababneh).

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**Resonance Reactions Ja + JX + l = J (-1)l (Ja) (JX) = (J)**

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 and Radiation Physics, BAU, 1st Semester, (Saed Dababneh).

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**radiative capture (a,)**

Resonance Reactions 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 and Radiation Physics, BAU, 1st Semester, (Saed Dababneh).

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**Resonance Reactions 14N(p,) HW 33 Huge challenge to experimentalists**

Q = ?? EC = ?? ER = 2.0 MeV Formation via s-wave protons, J = ½, p = 0.1 MeV, dipole radiation E = 9.3 MeV, = 1 eV. Show that = 0.33 eV. If same resonance but at ER = 10 keV p = ?? E = ?? = ?? Show that = 3.3x10-23 eV. Huge challenge to experimentalists Nuclear and Radiation Physics, BAU, 1st Semester, (Saed Dababneh).

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**Resonance J Estimated**

-transfer reactions Angular distribution Resonance J Estimated Energy (keV) (eV) Experimental upper limit < 1.7 eV 18O(, )22Ne Nuclear and Radiation Physics, BAU, 1st Semester, (Saed Dababneh).

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