Thesis topics in Physics (for October 2024)

Application deadline: 10th May 2024.

1. Cosmology with gravitational lensing of the cosmic microwave background
   • Supervisor: dr hab. Paweł Bielewicz, prof. NCBJ
   • Description: This PhD project will involve research on different aspects of the CMB gravitational lensing effect including developing and implementation of algorithms for estimation of the gravitational lensing potential, cross-correlations with galaxy and radio surveys, correcting CMB maps for the lensing effect and constraining amplitude of the primordial gravitational waves and sum of neutrino masses. The PhD student will analyse publicly available data from the Planck satellite and other ongoing and near future CMB experiments. The cross-correlation studies will be realized within the framework of the Rubin Observatory Legacy Survey of Space and Time survey. We seek strongly motivated PhD candidates with interest in cosmology who have experience in programming and numerical methods.
     Gravitational lensing of the cosmic microwave background (CMB) is a relativistic effect caused by the gravitational interaction of the CMB photons with matter inhomogeneities encountered during their travel from the last scattering surface to an observer. Reconstructed from correlated CMB ansiotropy gravitational potential of the lensing structures projected along the line-of-sight gives a unique image of the formation of the large scale structure at high redshifts and enables testing cosmological models at large scales. On the other hand, generated by the lensing effect divergence-free component of CMB polarisation has to be precisely estimated and corrected to be able to detect primordial gravitational waves produced during the inflationary epoch.
   • Funding: NCBJ
2. A comprehensive approach to the studies of gallium oxide implanted with rare earth ions for future optoelectronic device applications
   • Supervisor: prof. dr hab. Elżbieta Guziewicz
   • Co-Supervisor: dr hab. Renata Ratajczak
   • Description: Gallium Oxide (Ga2O3) is one of the currently most popular materials, that has attracted great attention from the scientific community. According to our project plan, this material’s properties will be modified by doping with Rare Earth (RE) using ion implantation. Such Ga2O3:RE systems could be essential for future applications in optoelectronics. In your work, you will deal with the structural, electrical, and optical research of a range of physical phenomena related to the ion implantation process, as well as designing the parameters to obtain efficient monochromatic light source emitters based on this material. An extremely important part of your studies is going to be the development of the Ga2O3 technology using the Atomic Layer Deposition (ALD) growth method. For the structural characterization of RE implanted Ga2O3, both bulk single crystals and ALD layers, mainly the RBS/c analytical technique, and comparative methods like Raman and XRD analysis will be used. You are going to be involved in the PL and Hall effect measurements too. Most of these investigations will be realized outside NCBJ, mainly at the Institute of Physics PAS, Warsaw, Poland. If you join us, you will also have a great opportunity to perform experimental investigations in many other European research centers as well as present results at international conferences. We are looking for candidates with basic knowledge of structural or optical studies of monocrystals. Experience in layer growing with the ALD technique will be well-received.
   • Funding: NCN
3. Impact of radiation damage on mechanical and structural properties of martensitic ferritic steels
   • Supervisor: dr hab. Łukasz Kurpaska, prof. NCBJ
   • Co-Supervisor: dr Peter Haehner
   • Description: Materials under neutron irradiation are subject to irradiation damage and degradation of their mechanical properties. However, neutron irradiation studies for research purposes are complicated, time-consuming, and expensive, so emulating neutron irradiation damage by much faster and cost-effective ion irradiation is of high interest. At the same time, ion irradiation avoids activation of the irradiated material. However, the emulation of neutron irradiation by ion irradiation damage is limited by transferability issues and experimental uncertainties linked to the limited penetration of the energetic ions.
     The goal of the work is to improve our understanding of the phenomena associated with the formation and evolution of ion irradiation-induced defects and their role in the deformation behavior in ferritic/martensitic (f/m) steels, incl. pure Fe, Fe9%Cr, Fe9%Cr-NiSiP and Eurofer 97. Nanoindentation will be carried out using different indenter shapes to study irradiation hardening. Radiation-induced defects will be identified by TEM. Complementary analyses will be carried out, including plasma-focused ion beam tomography of indents.
     The project aims at establishing and validating a comprehensive testing protocol with complementary investigations to support the experimental activities. An experimental/computational procedure is targeted for effectively characterizing ion irradiation as a surrogate for neutron irradiation. The project will also contribute to developing and validating models for size effects during nanoindentation in irradiated steels through a statistical sampling approach across a specimen surface. It is well known that size effects are influenced by irradiation; however, the origin has been debated. Micromechanical models and validation experiments will be performed that will account for geometrically necessary dislocations generated at the indent. Based on dislocation dynamics formulations in samples with various defects/defect clusters, a machine-learning approach will be developed to evaluate nanoindentation responses in irradiated metals.
     The Ph.D. project is expected to effectively improve experimental/computational protocols for the fast, safe, and reliable assessment of the irradiation impact on the mechanical properties of structural steels.
     The topic is in line with the research carried out by the NCBJ and in line with the mission of the JRC. Therefore, the Ph.D. candidate will conduct his/her research for up to 24 months at the Joint Research Centre in Petten under employment as a grant holder through the Collaborative Doctoral Partnerships (CDP) scheme (Agreement n. 36149). The candidate will be enrolled in NCBJ Ph.D. school and awarded a Ph.D. Degree in Physics at the end of the three to four-year Programme after successfully completing the entire Ph.D. requirements, including the successful defense of the Thesis as provided by the NCBJ Ph.D. school Regulations on Ph.D. Programmes.
   • Funding: NCN
4. Low surface brightness galaxies in the LSST era
   • Supervisor: dr Katarzyna Małek, prof. NCBJ
   • Auxiliary Supervisor: dr Junais
   • Description: The upcoming Legacy Survey of Space and Time (LSST) will be the benchmark for the next decade, providing unprecedented depth and quality optical data on millions of galaxies, including low and high surface brightness galaxies, LSBs and HSBs, respectively. This PhD project focuses on the identification and analysis of LSBs, which are very diffuse and fainter than the typical night sky, using the LSST data. The PhD student will investigate intermediate galaxies between LSBs and HSBs to understand if there is an intrinsic separation or continuity between the two populations.
     In the framework of this project, the PhD candidate will perform morphological analysis on these galaxies to estimate their properties such as size, surface brightness, and concentration. Several widely used tools like Galfit, Photutils, Autoprof, and machine learning techniques will be used to compare and evaluate the robustness of different tools for optimal morphological estimation of faint galaxies. The student will also carry out a multi-wavelength analysis of these galaxies by compiling ancillary data from the literature (e.g., GALEX, Spitzer, JWST, Herschel). The CIGALE tool will be used to perform Spectral Energy Distribution (SED) fitting techniques to estimate the stellar mass, star-formation rate, and dust attenuation of the galaxies.
     Our team is an active member of the LSST collaboration with access to early data releases that will be available at the beginning of the 2024 year. We also have experts in the field of LSBs, galaxy morphology, as well as SED fitting. Therefore, this PhD project offers a unique opportunity for the student to gain expertise in all these aspects. The results of this research will provide essential insights into the nature of very faint galaxies and their role in galaxy formation and evolution scenarios.
   • Funding: NCBJ
5. Designing and testing (high entropy) metallic glasses in experiment
   • Supervisor: prof. dr hab. Mikko Alawa
   • Auxiliary Supervisor: dr Silvia Bonfanti
   • Description: Metallic glasses are a new frontier of materials research. They are metastable materials and the glass properties depend crucially on the composition and the processing route or cooling. In this project, we test novel theoretical ideas of how to make good glasses and try to understanding their process-structure-property relationship.
     The goal of the work is testing predictions by making glasses and comparing with modelling. The experiments involve magnetron sputtering, and suction casting for sample preparation, and characterization with TEM, DSC, and nanoindentation. Moreover, the candidate will be interacting with the team working on metallic glasses including theorists.
   • Funding: NCN