Mart Pothast, PhD at Nikhef, will defend his thesis Friday 15 September 2023 at 10.30 at the Radboud University.
” Ultra-high-energy cosmic particle identification”
This thesis investigates ultra-high-energy cosmic rays, particles from space with the highest energy ever measured. These particles can tell us a lot about the universe and particle physics. Unfortunately, their sources and how these particles obtain their energy are still unknown.
Cosmic rays consist of atomic nuclei that collide with the atmosphere with tremendous energy, generating a shower of secondary particles. The Pierre Auger Observatory can measure these showers using telescopes and water tanks.
A novel method is developed in this thesis that utilizes the time-dependent signal measured with the water detectors. This method allows determining the point in the atmosphere with the highest number of particles (Xmax), which serves as a measure of the particle’s mass. The findings reveal that at the highest energies, the average mass of cosmic particles increases with energy.
Accurate measurement of Xmax with the water detectors is a good step towards identifying the type of cosmic particles and understanding the astrophysical sources of ultra-high-energy cosmic rays.
” Ultra-high-energy cosmic particle identification” (pdf)
The PhD defense will take place on Friday 15 September, at 10.30 in the Aula of the Radboud University Nijmegen, Comeniuslaan 2, Nijmegen
The defense will be broadcasted online: link.
More information on the website of the Radboud University
Supervisors: prof. dr. S.J. de Jong en prof. dr. C.W.J.P. Timmermans
contact: Mart Pothast