Test of traditional vibrational wisdom by 2 proton stripping onto targets of 108;110Pd,114Cd,115In

Philosophiae Doctor - PhDThe cadmium nuclei have traditionally been regarded as among the best examples of spherical vibrational nuclei. However, advances in nuclear spectroscopy have begun to detail the properties of these nuclei at the two and three vibrational phonon levels, casting doubts on the vibrational assumptions. In particular, the properties of the excited 0+n (for n 2) levels are key to any vibrational model. Excited 0+ states can arise in nuclei in association with the nucleon pairing degrees of freedom, and in model spaces with collective shape degrees of freedom. This thesis reports details of the excited 0+n levels in the even-even nuclei 110;112Cd and 116Sn, and the excited 9 2 + states in 117Sb, investigated using two-proton stripping reactions. The 108;110Pd(3He, n )110;112Cd, 114Cd(3He, n )116Sn and 115In(3He, n )117Sb reactions were investigated using AFRODITE spectrometer in conjunction with a wall of 12 plastic scintillator detectors placed 2 m away from the target chamber

Characterization of incomplete fusion reactions with DIAMANT and AFRODITE

M.Phil. (Chemistry)This project concerns the study of , specifically, the incomplete fusion mechanism. The nuclear reaction 7Li + 176Yb at 50 MeV was therefore carried out using the AFRODITE and DIAMANT facility of iThemba LABS. A 7Li nuclide is considered suitable for the breakup fusion (incomplete fusion) reaction because of its well developed cluster structure of an -particle and triton which are weakly bound in this nucleus. One of the breakup fragments may be captured by the target while the other escapes at the beam velocity. Light charged-particles (alpha, tritons, deuterons and protons) were detected with the DIAMANT (CsI) array in co-incidence with gammarays detected by the AFRODITE (HPGe) spectrometer. The light particle detection in co-incidence with gamma detection was an important innovation that allowed exclusivity in the reconstruction of the mechanism by which specific residues were produced. Off-line data processing was used to produce charged-particle-gated gamma-gamma coincidence matrices which were analysed with the RADWARE software package. The level scheme exclusive to a particular channel for the production of the 178Hf was extracted. The relative cross-section for the various reaction channels could also therefore be extracted. In particular, the intensity ratios of gamma transitions as function of spin for proton to triton-gated matrices populating the 178Hf isotope were extracted. Insights could be developed into the incomplete fusion reaction mechanisms initiated by the breakup of the incident 7Li projectile

Encapsulated Sulfur targets for light ion beam experiments

A new method was developed to produce enriched Sulfur targets with minimum loss of material. This was made possible by inserting Sulfur in-between two 0.5 μm Mylar foils (C10H8O4). The initial aim was to ensure that the Sulfur targets reduce by no more than 50% of the initial thickness within 24 hours under the equivalent of 10 J/cm2 of integrated energy deposition by an energetic (Eb > 50 MeV) proton beam. There is no loss of enriched material while making the target, as all the material is deposited within the surface area to be exposed to the beam. During beam irradiation, the targets were frequently swivelled in order to expose each part of the target to the beam and achieve homogeneous irradiation. Targets of 0.4 mg/cm2 thickness were produced and characterised using ion beam analysis technique with a 3 MeV proton beam

Encapsulated Sulfur targets for light ion beam experiments

A new method was developed to produce enriched Sulfur targets with minimum loss of material. This was made possible by inserting Sulfur in-between two 0.5 μm Mylar foils (C10H8O4). The initial aim was to ensure that the Sulfur targets reduce by no more than 50% of the initial thickness within 24 hours under the equivalent of 10 J/cm2 of integrated energy deposition by an energetic (Eb > 50 MeV) proton beam. There is no loss of enriched material while making the target, as all the material is deposited within the surface area to be exposed to the beam. During beam irradiation, the targets were frequently swivelled in order to expose each part of the target to the beam and achieve homogeneous irradiation. Targets of 0.4 mg/cm2 thickness were produced and characterised using ion beam analysis technique with a 3 MeV proton beam

Encapsulated Sulfur targets for light ion beam experiments

International audienceA new method was developed to produce enriched Sulfur targets with minimum loss of material. This was made possible by inserting Sulfur in-between two 0.5 μm Mylar foils (C10H8O4). The initial aim was to ensure that the Sulfur targets reduce by no more than 50% of the initial thickness within 24 hours under the equivalent of 10 J/cm2 of integrated energy deposition by an energetic (Eb > 50 MeV) proton beam. There is no loss of enriched material while making the target, as all the material is deposited within the surface area to be exposed to the beam. During beam irradiation, the targets were frequently swivelled in order to expose each part of the target to the beam and achieve homogeneous irradiation. Targets of 0.4 mg/cm2 thickness were produced and characterised using ion beam analysis technique with a 3 MeV proton beam