High-energy particles constantly bombard Earth. Charged, relativistic particles, referred to as cosmic rays (CRs), are deflected on their way through the magnetised Universe towards Earth. This characteristic of CRs obscures their origin to this day. The importance of CRs in astrophysical systems of all sizes is known in great detail, from planetary systems up to the interstellar medium and even galaxy clusters. On Earth, we can observe the influence of CRs through polar lights. Here, CRs ionise and excite the atmospheric constituents that emit visible light.
To unmask the CR origin, analytical theories, numerical simulations and indirect observations are employed instead. Despite decades of research, we still have not unravelled the mystery of the CR's origin. To make further progress, the Oxford group I will be working with recently mimicked the transport of CRs through the intergalactic medium in a laboratory experiment for the first time. They used powerful laser systems, among them the most energetic laser in the world, capable of bringing the powerful dynamics of the Universe to the laboratory. This was a milestone in establishing laboratory physics as a new pillar alongside analytical theories, numerical simulations and observations.
I will start my Gateway project at the Physics department of the University of Oxford in mid-February 2023: We will literally shoot laser beams whose total power is equivalent to that of 10,000 nuclear reactors onto plastic foil targets to mimic astrophysical explosions.