Description du sujet de thèse

PhD position in physics for the TESSERACT experiment which aims for the direct detection of dark matter in the universe.
The thesis project we are proposing is part of the international TESSERACT collaboration, whose objective is to detect the signature of dark matter by its interaction with detectors operating at cryogenic temperatures, generally around 0.01 K. Several teams involved in this collaboration are working on the development of detectors using superconducting sensors and various target materials. The main challenge of the proposed thesis is the development at IJCLab of innovative Ge detectors, their calibration and ultimately their exploitation in underground sites. An experimental device using a dilution cryostat will be installed in 2028 in a very low radioactivity environment at the Modane Underground Laboratory (LSM), and will allow the first direct dark matter search measurements to be carried out with these detectors. Active research will be conducted to develop cryogenic Ge ionization-heat detectors that simultaneously measure charge and temperature with performance very close to their quantum limits (electron-hole pair ionization resolution and calorimetry limited by Ge thermodynamic temperature fluctuations). The doctoral student will play a central role in all key stages of this experimental development, including the design and development of innovative Ge detectors, ultra-low-temperature testing and calibration at IJCLab, as well as data analysis and modeling. Different Ge detector configurations will be explored and compared in terms of energy threshold and rejection of background events. In addition, the student will actively participate in the integration of the detectors at the Modane underground laboratory and in the exploitation of the results for dark matter research within the TESSERACT collaboration.
This work will also have significant implications in the field of neutrino physics, paving the way for highly accurate detection of coherent elastic neutrino-nucleus scattering (CEνNS) near a nuclear reactor. The IJCLab ASSD team is involved in the RICOCHET collaboration, which aims to study CEνNS at the ILL reactor in Grenoble.

Contexte de travail

The Irène Joliot-Curie Physics Laboratory of 2 Infinities (IJCLab) is a UMR under the supervision of the CNRS (IN2P3), the University of Paris-Saclay and the University of Paris is located on the campus of the University of Paris -Saclay in Orsay. The laboratory is located on the campus of the Université Paris-Sud, Université Paris-Saclay in Orsay. The campus is located 20 km south of Paris and easily accessible by RER in 35 minutes.
IJCLab was born in 2020 from the merger of five units (CSNSM, IMNC, IPN, LAL, LPT). The staff is made up of nearly 560 permanent (340 engineers, technicians and administrators and 220 researchers and teacher-researchers) and approximately 200 non-permanent including 120 doctoral students. The research themes of the laboratory are nuclear physics, high energy physics, theoretical physics, astroparticles, astrophysics and cosmology, particle accelerators, energy and the environment and health. IJCLab has very significant technical capacities (around 280 IT) in all the major fields required to design, develop / implement the experimental devices necessary for its scientific activity, as well as the design, development and use of instruments. .
The PhD student will work in the ASSD group of the Laboratory which is involved in several major projects for Dark Matter research and Neutrino Physics.
The group includes around 10 physicists (permanent researchers, post-docs and doctoral students).
IJCLAB bases its recruitment policy on the promotion of equality, diversity and inclusion. Essential values, they allow the professional development of agents, who are real actors in a collective success, but also the development of the laboratory itself.

Le poste se situe dans un secteur relevant de la protection du potentiel scientifique et technique (PPST), et nécessite donc, conformément à la réglementation, que votre arrivée soit autorisée par l'autorité compétente du MESR.

Contraintes et risques

The successful candidate shall be enrolled on a PhD programme of the Pheniics doctoral school. Travel to Laboratoire Souterrain de Modane should be expected for the installation and commissioning of the developed cryogenic detectors.