Thesis

LATTES: A next-generation detector for gamma-ray astrophysics in South America

• Call:

  IDPASC Portugal - PHD Programme 2016

• Academic Year:

  2016 / 2017

• Domains:

  Experimental Particle Physics | Astroparticle Physics

• Supervisor:

  Bernardo Tomé

• Co-Supervisor:

  Ruben Conceição

• Institution:

  Instituto Superior Técnico

• Host Institution:

  Laboratório de Instrumentação e Física Experimental de Partículas

• Abstract:

  Very high-energy (VHE) cosmic gamma rays are messengers of violent processes in the universe. In particular, their production is closely connected with the particle acceleration of the very high-energy charged cosmic rays detected on Earth. VHE photons are thus key to understand the long-standing mystery of the mechanism by which cosmic rays are accelerated. Also, their intergalactic propagation across very large distances is sensitive to possible modifications of the structure of space-time on the Planck scale. Moreover, the detection of VHE gamma rays may provide a clue to the nature of the dark-matter (DM). In fact, weakly interacting massive particles (considered the most plausible form of DM) are expected to mutually annihilate, giving rise to the creation of particles namely VHE gamma rays. Dark-matter particles tend to accumulate at the centres of the galaxies. As such the centre of our galaxy is a preferred spot to look for these DM signals. While most VHE gamma-ray detectors currently in operation are located in the northern hemisphere, several of the next-generation detectors are planned to be installed in the southern hemisphere, in order to have a privileged view of the galactic centre. In this context LATTES (Large Area Telescope for Tracking Energetic Sources) is a project, currently involving groups from Brazil, Italy and Portugal (LIP), aiming to develop a next-generation gamma-ray detector to be installed in the South America. The region of the Atacama Desert in the northern Chile, at an altitude above 5000 metres, is one of the most promising sites. One of the biggest challenges to be addressed by LATTES is to bridge the gap between gamma-ray observations using satellites such as Fermi, sensitive up to several tens of GeV and the present and planned gamma-ray ground based experiments, which start to be sensitive at only several hundreds of GeV. By employing a hybrid detection technique and being deployed at high altitude, LATTES should be able to detect photons with energies as low as 100 GeV. The interested candidate will participate in the current and future activities of the LIP/LATTES group, namely: - Simulation of the LATTES detector concept using the Geant4 toolkit and air-shower simulation tools such as CORSIKA; - Development of data analysis tools and studies of the performance of the full scale detector; - Participation on the commissioning of the detector; - Exploration of the capabilities of the LATTES concept in gamma-ray astroparticle physics.