Author: Christopher Walz
Publisher: Springer
ISBN: 3319271830
Category : Science
Languages : en
Pages : 169
Book Description
This work focuses on new electromagnetic decay mode in nuclear physics. The first part of the thesis presents the observation of the two-photon decay for a transition where the one-photon decay is allowed. In the second part, so called quadrupole mixed-symmetry is investigated in inelastic proton scattering experiments. In 1930 Nobel-prize winner M. Goeppert-Mayer was the first to discuss the two-photon decay of an exited state in her doctoral thesis. This process has been observed many times in atomic physics. However in nuclear physics data is sparse. Here this decay mode has only been observed for the special case of a transition between nuclear states with spin and parity quantum number 0+. For such a transition, the one-photon decay – the main experimental obstacle to observe the two-photon decay – is forbidden. Furthermore, the energy sharing and angular distributions were measured, allowing conclusions to be drawn about the multipoles contributing to the two-photon transition. Quadrupole mixed-symmetry states are an excitation mode in spherical nuclei which are sensitive to the strength of the quadrupole residual interaction. A new signature for these interesting states is presented which allows identification of mixed-symmetry states independently of electromagnetic transition strengths. Furthermore this signature represents a valuable additional observable to test model predictions for mixed-symmetry states.
The Two-photon Decay of the 11/2- Isomer of 137Ba and Mixed-symmetry States of 92,94Zr and 94Mo
The Two-Photon Decay of the 11-/2 Isomer of 137Ba and Mixed-Symmetry States of 92,94Zr and 94Mo
Author: Christopher Walz
Publisher: Springer
ISBN: 3319271830
Category : Science
Languages : en
Pages : 169
Book Description
This work focuses on new electromagnetic decay mode in nuclear physics. The first part of the thesis presents the observation of the two-photon decay for a transition where the one-photon decay is allowed. In the second part, so called quadrupole mixed-symmetry is investigated in inelastic proton scattering experiments. In 1930 Nobel-prize winner M. Goeppert-Mayer was the first to discuss the two-photon decay of an exited state in her doctoral thesis. This process has been observed many times in atomic physics. However in nuclear physics data is sparse. Here this decay mode has only been observed for the special case of a transition between nuclear states with spin and parity quantum number 0+. For such a transition, the one-photon decay – the main experimental obstacle to observe the two-photon decay – is forbidden. Furthermore, the energy sharing and angular distributions were measured, allowing conclusions to be drawn about the multipoles contributing to the two-photon transition. Quadrupole mixed-symmetry states are an excitation mode in spherical nuclei which are sensitive to the strength of the quadrupole residual interaction. A new signature for these interesting states is presented which allows identification of mixed-symmetry states independently of electromagnetic transition strengths. Furthermore this signature represents a valuable additional observable to test model predictions for mixed-symmetry states.
Publisher: Springer
ISBN: 3319271830
Category : Science
Languages : en
Pages : 169
Book Description
This work focuses on new electromagnetic decay mode in nuclear physics. The first part of the thesis presents the observation of the two-photon decay for a transition where the one-photon decay is allowed. In the second part, so called quadrupole mixed-symmetry is investigated in inelastic proton scattering experiments. In 1930 Nobel-prize winner M. Goeppert-Mayer was the first to discuss the two-photon decay of an exited state in her doctoral thesis. This process has been observed many times in atomic physics. However in nuclear physics data is sparse. Here this decay mode has only been observed for the special case of a transition between nuclear states with spin and parity quantum number 0+. For such a transition, the one-photon decay – the main experimental obstacle to observe the two-photon decay – is forbidden. Furthermore, the energy sharing and angular distributions were measured, allowing conclusions to be drawn about the multipoles contributing to the two-photon transition. Quadrupole mixed-symmetry states are an excitation mode in spherical nuclei which are sensitive to the strength of the quadrupole residual interaction. A new signature for these interesting states is presented which allows identification of mixed-symmetry states independently of electromagnetic transition strengths. Furthermore this signature represents a valuable additional observable to test model predictions for mixed-symmetry states.
Search for the two-photon decay of the 2+ first excited states in O and Si 18O and 28Si
Search for the two-photon decay of the 2+ first excited states in 18O [hoch 18 O] and 28Si [hoch 28 Si]
The Two-photon Decay of 1s2s 1S° States in Heavy He-like Atomic Systems
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 5
Book Description
In He-like systems the decay of the 1s2s 1S0 excited state to the 1s2 1S0 ground state is not allowed. This excited state can only decay to the ground state via the emission of two photons. The spectral shape of the emitted continuum is determined by the complete structure of the atomic system as all bound and continuum P states contribute to the 2E1 decay. For very heavy atomic systems the 3P states ALSO have to be included and the normalized spectral shape changes with atomic number according to the relative strengths of both, the electron-electron interaction and of the relativistic effects. A brief survey on the variation of the spectral shape of the two-photon continuum with atomic number is given and compared to experiments ranging from He-like Ni to He-like Au with special emphasis on the heavy relativistic system. The data compare well with fully relativistic calculations.
Publisher:
ISBN:
Category :
Languages : en
Pages : 5
Book Description
In He-like systems the decay of the 1s2s 1S0 excited state to the 1s2 1S0 ground state is not allowed. This excited state can only decay to the ground state via the emission of two photons. The spectral shape of the emitted continuum is determined by the complete structure of the atomic system as all bound and continuum P states contribute to the 2E1 decay. For very heavy atomic systems the 3P states ALSO have to be included and the normalized spectral shape changes with atomic number according to the relative strengths of both, the electron-electron interaction and of the relativistic effects. A brief survey on the variation of the spectral shape of the two-photon continuum with atomic number is given and compared to experiments ranging from He-like Ni to He-like Au with special emphasis on the heavy relativistic system. The data compare well with fully relativistic calculations.