1. Full name: Vi Ho Phong                                             2. Sex: Male

3. Date of birth: 29/09/1989                                            4. Place of birth: Quang Ninh

5. Admission decision number: decision No. 3173 /QĐ-ĐHKHTN signed on 09/09/2014 by the Rector of VNU University of Science.

6. Changes in academic process: Extension according to: decision No. 4217/QĐ-ĐHKHTN signed on 14/12/2018 and decision No. 4728/QĐ-ĐHKHTN signed on 28/12/2018 by the Rector of VNU University of Science.

7. Official thesis title: Nuclear structure studies of neutron-rich isotopes of 129-131Ag, 130-133Cd, 131-135In and 134-138Sn via -delayed neutron measurements using the briken detector system

8. Major: Nuclear Physics                                              9. Code: 9440130.04

10. Supervisors: Prof. Dr. Le Hong Khiem, Dr. Shunji Nishimura

11. Summary of the new findings of the thesis

- Determined the delayed 1 and 2 neutrons emission probabilities(P1n và P2n) of neutron-rich isotopes including: 129-131Ag, 130-133Cd, 131-135In và 134-138Sn, of which 7 new P1n values were obtained for the first time, together with 2 new P1n values for 134In và 135In.

- Determined the life-times of 17 isotopes: 129-131Ag, 130-133Cd, 131-135In và 134-138Sn and compare with previous measurements in literature.

- Determined an isomeric state of 134In with the excitation energy of 56.7 keV, an half-life of 3.5 3.5 s and tentatively-assigned spin-parity of 5- and proposed discussions accordingly.

- Performed GEANT4 simulations for the BRIKEN neutron detector system.

- Provided nuclear data on delayed 1 and 2 neutrons emission probabilities of radioactive isotopes around the doubly magic nuclei 132Sn. This allows the astrophysictist to perform more accurate astrophysical simulations on the nuclear synthesis of heavy nuclei via rapid-neutron capture process.

12. Practical applicability, if any:

Some of the experimental techniques used in present thesis can be utilized for some applications in practice, such as (1) Precise determination of -delayed neutron emission probability can help to improve the current nuclear database for nuclear reactor applications; (2) Development of 3He-based counter array to detect neutrons for nuclear safety and nonproliferation applications; (3) Utilization of GEANT4 simulation for various applications in nuclear medicines, radiation protection,

13. Further research directions, if any:

For further studies, the author will analyze the BRIKEN data from the lower mass region (A ≈ 100), where the systematic change of the Pxn values are predicted to be sensitive with nuclear deformation.

14. Thesis-related publications:

[1] Phong V. H., Nishimura S. and Khiem L. H. (2018), “Evaluation of Simultaneous Fitting Method for β-Decay Half-Lives and β-Delayed Multi Neutron Emission Probabilities Developed for the BRIKEN Experiment”. Communications in Physics, 28(4), pp. 311-321.

[2] Phong V. H., Lorusso G., et. al. (2019), “Observation of a µs isomer in (_49^134)〖In〗_85  : proton-neutron coupling south-east of (_50^132)〖Sn〗_82 ”, Physical Review C 100.1, p. 011302.[3] Phong V. H., Nishimura S., Estrade A., Montes F., Lorusso G., Davinson T., Hall O., Liu J. for  the BRIKEN collaboration (2019). “Beta-decay measurements of very neutron-rich isotopes around mass A=130 within the BRIKEN project at RIBF”. In Proceedings of the 15th International Symposium on Origin of Matter and Evolution of Galaxies (OMEG15), accepted.