Missions

The CROSS project is developing a demonstrator of an innovative technology for the search for neutrinoless double beta decay of the two isotopes Mo-100 and Te-130. The demonstrator will be installed in the Canfranc underground laboratory (Spain) in the second half of 2024. The demonstrator will also test crucial experimental aspects of the CUPID detectors. CUPID is another double-beta-decay experiment with strong connections with CROSS. The post-doc will work about the development of this demonstrator and the related prototypes, following the detector conception, construction and data analysis. It is expected that the demonstrator will achieve the most sensitive worldwide physics results on the double beta decay of Mo-100 and other related rare processes. The post-doc's activity will mainly take place in the cryogenic detector group of IJCLab (named ASSD, in the pole Astroparticle, Astrophysics and Cosmology), led by Andrea Giuliani. Frequent missions to the Canfranc underground laboratory are foreseen for detector installation and data taking.

Activités

The post-doctoral fellow will be in charge of:
• developing detector prototypes for the CROSS demonstrator, consisting of luminescent bolometers based on Li2MoO4 and TeO2 crystals grown with materials enriched in Mo-100 and Te-130
• studying and optimizing bolometric light detectors based on the Neganov-Trofimov-Luke effect
• performing above-ground tests of the developed prototypes, both of light detectors and of the complete scintillating bolometers
• developing detector elements sensitive to surface events, thanks to thin film coating of the crystal surface with appropriate metallic materials
• performing the full data analysis of the prototypes, extracting significant experimental parameters of the detectors as the energy resolution, the alpha/beta discrimination power, the time resolution and the radiopurity level of the main employed materials
• installing the CROSS demonstrator in the Canfranc underground laboratory and starting the data taking
• following the initial data analysis of the demonstrator
• publication of one or more joint articles on the detector performance and of the demonstrator results.
It is expected that the data obtained will ultimately make it possible to set the most stringent worldwide limit on the neutrinoless double beta decay of Mo-100, the most sensitive measurement of the two-neutrino double beta decay of Mo-100 and the study of other exotic processes. The demonstrator will also validate crucial elements of the CUPID technology, as the crystal radiopurity and the light detector performance.

Compétences

• It is desirable, but not mandatory, that the candidate has a previous experience either on bolometric detectors for rare events or on the experimental search for neutrinoless double beta decay, or both.
• Experience on nuclear detectors in a wide sense, involving calibration and characterization methods, is very valuable.
• Experience on software development for detector data analysis will also be considered as a plus for a successful application.
• Holding a doctorate showing that the candidate has all or some of the aforementioned skills is mandatory
• Fluency in spoken and written English is required
• A demonstrated aptitude for working in a team with both hardware and software skills will be appreciated

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 researcher will work in the ASSD (Astroparticle Solid State Detectors) group of the Laboratory. The group is led by Andrea Giuliani and is involved in frontier experiments on neutrino physics and direct dark matter search, such as CUPID, RICOCHET and EDELWEISS.
The group includes around 10 physicists (permanent researchers, post-docs and doctoral students).

Contraintes et risques

Constraints and specific features of the post, possible travel requirements :
Short periods of travel to the Canfranc and Gran Sasso cryogenic laboratories are expected for detector installation and data taking
The post-doc contract will last 18 months. However, the CROSS project (and therefore the contract) will be over on December 31st, 2024. If, for any reason, the recruitment should take place after July 1st, 2023 the contract duration will be reduced accordingly.

Informations complémentaires

Experience required: experience in nuclear, particle or astroparticle physics

Submit a covering letter and CV without any break in date showing diplomas, titles and work and professional experience.
Attach at least two letters of recommendations of former supervisors, thesis directors or experienced co-workers.

As IJCLab is subjected to ZRR (Zone à Régime Restrictif) military regulation, hiring choices must be approved by the Haut Fonctionnaire Securité Défense (HFSD). Therefore, the date of employment written above should be understood as provisional, and may need to be delayed.