Thermal analysis for the ATLAS/LHC/CERN High Granularity Timing Detector
The High Granularity Timing Detector (HGTD) is a new detector of the ATLAS experiment, foreseen to operate during the high luminosity Phase-II of the LHC. The HGTD is designed to measure the arrival time and position of particles in the forward region with an unprecedented time resolution of 35 ps. The two sides of the HGTD are located at ±3.5 m from the interaction point (IP). Each side consists of two double-sided layers of Low-Gain Avalanche Detectors (LGAD), mounted on two large cooling plates inside an hermetic vessel. The Portuguese team is strongly involved in the design and construction of the detector, namely in the development of the HGTD Interlock System (HIS), which is a standalone safety system that protects the detector against a variety of threads. A key analysis is the assessment of thermal risks during an LHC beam pipe bake-out, in the hypothetical event of a cooling-system failure. Since bake-out procedures involve elevated and time-varying temperatures, understanding the resulting thermal load on HGTD components is essential for defining safe operating conditions and ensuring system robustness. The project focuses on performing this assessment through a finite-element analysis (FEM). The inputs will be the HGTD geometry and material/thermal properties. The goals are: Definition of the bake-out scenario, including the temperature evolution of the beam pipe, cooling-failure assumptions, and thermal boundary conditions. Establish risk criteria, such as maximum safe temperatures for LGAD sensors, ASICs, and the bump-bonded. Carry out FEM simulations to evaluate heat propagation and identify potential failure modes. Document and interpret the results, contributing to the safety specifications of the HGTD Interlock System. This is an international project. The student will work as member of the ATLAS Portuguese team and will work closely with the ATLAS-HGTD team, gaining experience in detector engineering, thermal modelling, and experimental physics operations.

Grupo : ATLAS
Local : Lisboa
Supervisor(s) : Helena Santos
Email : helena@lip.pt
Vagas : 1
Duração/Datas : February-June 2026