a) Gamma Decay Energy Gamma, y, rays are electromagnetic radiation emitted from atomic nuclei The bundles of energy emitted are called photons Excited nuclei are called isomers. and de-excitation is called isomeric transition(T) Energy for photons hv=EiEf dmNa 1t others G ramna hoton Decay
Gamma Decay Energy Gamma, , rays are electromagnetic radiation emitted from atomic nuclei. The bundles of energy emitted are called photons. Ei ____________ h v Ef ____________ Eothers _________ Excited nuclei are called isomers, and de-excitation is called isomeric transition (IT). Energy for photons h v = E i - E f a)
Nature of gamma transitions Types of Isomeric Transitions and their Ranges of Half-life Radiation Type Symbol△ △πPa artia al half life,(s) Electric dipole Yes5.7e-15E-3A12/3 Magnetic dipole No2.2e-14E3 Electric quadrupole E 2 o6.7e-9E-54/3 Magnetic quadrupole M2 Yes2.6e-8E52/3 Electric octupole Yes 1.2e-2E-7A-2 Magnetic octupole M Electric 24-pole 223344 No4.9e-2E-714/3 No3.4e4E9A8/3 Magnetic 24-pole M Yes 1.3e5E-94-4
Types of Isomeric Transitions and their Ranges of Half-life Radiation Type Symbol J Partial half life t (s) Electric dipole E1 1 Yes 5.7e-15 E–3 A–2/3 Magnetic dipole M1 1 No 2.2e-14 E–3 Electric quadrupole E2 2 No 6.7e-9 E–5 A–4/3 Magnetic quadrupole M2 2 Yes 2.6e-8 E–5 A–2/3 Electric octupole E3 3 Yes 1.2e-2 E–7 A–2 Magnetic octupole M3 3 No 4.9e-2 E–7 A–4/3 Electric 24 -pole E4 4 No 3.4e4 E–9 A–8/3 Magnetic 24 -pole M4 4 Yes 1.3e5 E–9 A–2 Nature of Gamma Transitions
Gamma Decay Energy and Spectrum Gamma transition of li Various gamma transitions in 7Ll 12+654MeV 2+4.64MeV 12-0.778MeV /2-ground state
Various Gamma Transitions in 7Li 3/2– ground state ½ – 0.778 MeV 7/2+ 4.64 MeV ½+ 6.54 MeV M1 E1 E3 M3 M2 Gamma Decay Energy and Spectrum Gamma transition of 7Li
Ey is the energy of the gamma photon, E* is the excitation energy(above the ground a)y decay: 2P+2P+y the recoil kinetic energy of the resulting ground-state nuclide M(aPcL=MP)c+E=M(p)c+E P +e y Gamma Ray Spectrum of o E ED+e P Q ntenSity 2n+ 3.27 Mev /2MPE 2+ C 1.98 Mev 1.98 0+ P mPc P 5.25 Mev E Q1+ Qr E 2M Intensities of the peaks are related to the the kinetic energy of the reco population of the excited state as well as the half life of the transition nucleus is negligible
Gamma Ray Spectrum of O18 E Intensity 2 h+ 2+ 0+ 3.27 MeV 1.98 1.98 MeV 3.27 MeV 5.25 MeV a) Intensities of the peaks are related to the population of the excited state as well as the half life of the transition. Eγ is the energy of the gamma photon, E* is the excitation energy (above the ground state) of the initial parent nucleus, and Ep is the recoil kinetic energy of the resulting ground-state nuclide. the kinetic energy of the recoil nucleus is negligible =Q