Oktupolideformaation vaikutus sähköisiin ja magneettisiin dipolisiirtymävoimakkuuksiin sekä fotoabsorbtiovaikutusalaan

Reflection-symmetry breaking octupole-deformed pear-like nuclear shape is an extraordinary collective property of the atomic nucleus, realized in rather limited areas of the nuclear chart. In turn, the electromagnetic response of the nucleus at the higher excitation energies is well-known to be affected by collective properties, such as the shape of the nucleus. In this master's thesis, for the first time, these two aspects are connected as a survey on the impact of octupole deformation on electric and magnetic dipole transition strengths as well as on the photoabsorption cross section, primarily focusing on the giant dipole resonance energy region. Research focuses on the actinide region of the nuclear chart concerning octupole deformed even-even isotopes of Th, U, Pu, and Cm with mass numbers between A = 222–230 and A= 288–290. The research is conducted using existing computational programs operating in the framework of Skyrme-HFB theory to determine the ground state properties of the studied isotopes. Based on the ground state solutions, nuclear electromagnetic dipole responses are examined in the framework of linear response theory using the well-established FAM-QRPA method. Octupole deformation is found to have little or no impact on E1 transition strengths and photoabsorption cross sections. Computed M1 transition strengths indicate octupole deformation having an impact on the magnetic transition strengths, especially in the spin-flip resonance region. As a side result, it is found that allowing the nucleus to have an octupole-deformed ground state may significantly decrease or flatten an artificial-seeming peak at the higher end of the giant dipole resonance region related to electric dipole transitions, apparently caused by features related to used SkM* Skyrme parametrization.