Iron- and steelmaking stand for about 8% of all global greenhouse gas emissions, which qualifies this sector as the biggest single cause of global warming. This originates from the use of fossil carbon carriers as precursors for the reduction of iron oxides. Mitigation strategies pursue the replacement of fossil carbon carriers by sustainably produced hydrogen and / or electrons as alternative reductants, to massively cut these CO2 emissions, thereby lying the foundations for transforming a 3000 years old industry within a few years. As the sustainable production of hydrogen using renewable energy is a bottleneck in green steel making, the gigantic annual steel production of 1.85 billion tons requires strategies to use hydrogen and / or electrons very efficiently and to yield high metallization at fast reduction kinetic. This presentation presents progress in understanding the governing mechanisms of hydrogen-based direct reduction and plasma reduction of iron oxides. The metallization degree, reduction kinetics and their dependence on the underlying redox reactions in hydrogen-containing direct and plasma reduction strongly depend on mass transport kinetics, Kirkendall effects, nucleation phenomena, chemical and stress partitioning, the oxide's chemistry and microstructure, the acquired and evolving porosity, crystal plasticity, damage and fracture effects associated with the phase transformation phenomena occurring during reduction. Understanding these effects, together with external boundary conditions such as other reductant gas mixtures, oxide feedstock composition, pressure and temperature, is key to produce hydrogen-based green steel and design corresponding direct reduction shaft or fluidized bed reactors, enabling the required massive C02 reductions at affordable costs. Possible simulation approaches that are capable of capturing some of these phenomena and their interplay are also discussed.

Theoretical predictions beyond tree-level are necessary for a meaningful comparison between theory and experiment. Their calculation makes it inevitable to deal with infrared (IR) divergencies, stemming from partons becoming soft or collinear. One way to overcome them is to resort to subtraction schemes. In this talk, I will present the antenna subtraction scheme and the current efforts to extend it to N3LO, focusing on the situation where hard radiators are both in the initial and in the final state. First, I will review the extension of the N2LO initial-final antennae to higher epsilon order and present a purely analytic strategy to fix the boundary conditions of the relevant phase-space integrals (based on the Auxiliary Mass Flow method). Finally, I present the status of the calculation of N3LO initial-final antennae and the theoretical machinery necessary to perform this it, which includes translating phase space integrals into cuts of loop integrals, finding a canonical basis and fixing boundary conditions.

For decades, we have been looking for Dark Matter in the form of WIMPs, but many other possibilities exist. Light DM, intended as having a mass between 1 MeV and about 1 GeV, is one of these possibilities, which is interesting both theoretically and phenomenologically. Testing it via Indirect Detection is more challenging than WIMPs, but X-ray measurements provide a very powerful handle. They currently impose stringent constraints, and allow in perspective to explore further this relatively new region of the parameter space.
Slides here...

Laser spectroscopy techniques provide nuclear-model independent access to nuclear properties, such as the electromagnetic moments, spins and charge radii. Advances in radioactive ion beam instrumentation and laser technologies have enabled the study of a wide range of elements and isotopes, pushing out far from the valley of stability towards the drip lines. In this seminar, I will present experimental progress along two important frontiers. I will discuss the use of methods based on laser ionization spectroscopy and how they have allowed us to reach exotic nuclei, such as 94Ag 52K, which have long been out of reach. The role of these measurements in furthering our understanding of the atomic nucleus will also be put into context. Besides using efficient laser ionization and particle detection methods, another important frontier is the precision frontier. I will focus on ongoing research which aims to perform optical and radiofrequency spectroscopy of radioactive ions while they are trapped in a linear Paul trap. I will discuss the status and first commissioning results of a new setup currently under construction at the KU Leuven.