Postdoctoral Researcher in Experimental Dark Matter Physics – TESSERACT (M/F)

Job Description

Missions

The postdoctoral researcher will contribute to the implementation of the TESSERACT project (Transition Edge Sensors with Sub-eV Resolution and Cryogenic Targets), an international collaboration aimed at detecting light dark matter using ultra-sensitive cryogenic detectors. Within the Neutrino group at LPSC, under the supervision of Silvia Scorza, he/she will lead the commissioning of the TESSERACT cryostat and its shielding, and will develop simulation and radioactive background analysis tools..

Activity

-Radioactive background budget and material specifications (primary task) Develop and maintain a detailed radioactive background budget by component (Ge/Si detectors, cryostat, shielding, cabling, mechanical supports) in line with TESSERACT scientific objectives. Estimate cosmogenic activities (tritium accumulation in Ge/Si crystals, copper activation by spallation) as well as background rates related to internal material contamination (U/Th/K chains), surface contamination, environmental gammas, and residual neutrons. Develop and validate the Geant4 simulation framework by comparison with HPGe spectrometry (Gentiane, LSM) and alpha contamination measurements (XIA UltraLo-1800), and iteratively populate the radiopurity.org database.
-Procedures, monitoring, and tracking of radioactive exposures (primary task) Supervise and revise control procedures for the three exposure sources: cosmogenic activation, with planning of crystal and copper storage and transport to minimise cosmic ray exposure; radon exposure, ensuring adequate mitigation; and particulate contaminants, ensuring that accumulated dust does not add a contribution to the radiogenic background.
-Cryostat and shielding coordination and commissioning (primary task) Coordinate and finalise the commissioning plan for the cryogen-free dilution cryostat (base temperature ~10 mK) and its multi-layer shielding (high-density polyethylene, lead, mu-metal) at LPSC. Analyse cryostat performance data, including vibrations, magnetic shielding, and thermal stability.
-Additional responsibilities (secondary tasks) Produce technical documentation and contribute to progress reviews of the international TESSERACT collaboration. Supervise master and PhD students involved in radiopurity and simulation studies

Your Profil

Skills

- PhD in particle physics, nuclear physics, astroparticle physics, or a related field [required]
- Experience in detector instrumentation (ideally cryogenic detectors, TES, bolometers) [strongly desired]. Proficiency in Monte-Carlo simulations (Geant4 or equivalent) [required]
- Skills in experimental data analysis (C++, Python, ROOT) [required].
- Knowledge of radiopurity measurement techniques and low-background methods [desired]. - Ability to work in an international collaboration and write technical reports in English [required].
- Autonomy, rigour, and organisational skills to coordinate complex commissioning tasks [required]
- Experience in student supervision [appreciated]
Training in radiation protection procedures and safety regulations specific to the underground environment (LSM, Modane) will be provided internally.

Your Work Environment

The Subatomic Physics and Cosmology Laboratory of Grenoble (LPSC) (http://lpsc.in2p3.fr) is a joint research unit combining CNRS-IN2P3, the Université Grenoble Alpes (UGA), and Grenoble INP, with an average staff of approximately 230 people.
The postdoctoral researcher will be assigned to the Neutrino group at LPSC. He/she will work under the direct supervision of Silvia Scorza and will report directly to the head of the LPSC Neutrino group. The position involves regular travel to the Modane Underground Laboratory (LSM) and frequent interactions with national (IP2I Lyon, IJCLab Orsay) and international (DOE – United States, University of Zurich) partners.
LPSC is a member of the ENIGMASS+ network and benefits from expertise in the EDELWEISS and RICOCHET programmes. The laboratory has the necessary equipment for cryostat commissioning and radiopurity screening tools. The postdoctoral researcher will benefit from a high-level scientific and technical environment, at the crossroads of particle physics, cosmology, and cryogenic instrumentation.

Constraints and risks

The position involves radiation protection constraints during measurement campaigns at LSM (Modane). Regular travel within France and abroad (United States, Switzerland) is expected. Work in a cryogenic environment (liquid nitrogen, helium).

Compensation and benefits

Compensation

Starting at €3,041.58 gross, depending on professional experience

Annual leave and RTT

44 jours

Remote Working practice and compensation

Pratique et indemnisation du TT

Transport

Prise en charge à 75% du coût et forfait mobilité durable jusqu’à 300€

About the offer

About the CNRS

The CNRS is a major player in fundamental research on a global scale. The CNRS is the only French organization active in all scientific fields. Its unique position as a multi-specialist allows it to bring together different disciplines to address the most important challenges of the contemporary world, in connection with the actors of change.

CNRS

The research professions