Post-doctoral researcher in experimental nuclear physics: commissioning of the SIRIUS detector (M/F)

CNRS - National Center for Scientific Research; France; On-site; EUR 42,000 - 64,000; Full time

Job summary

The CNRS - National Center for Scientific Research, via the Irène Joliot-Curie Lab (IJCLab) in Orsay, seeks a postdoctoral researcher to lead detector and ASIC tests for the SHEXI upgrade of SIRIUS. The role involves commissioning, off-site collaboration if needed (e.g., Finland), data analysis, and dissemination of results.

Applicants should hold a PhD in experimental nuclear physics with published work, and be proficient in silicon detectors, electronics, and C++/ROOT.

Qualifications

• Doctorate in experimental nuclear physics required.
• At least one publication as first or joint first author in a related project.
• Demonstrable knowledge of silicon detectors and their operation.
• Demonstrable knowledge of front- and back-end electronics and their operation.
• Ability to work both in a team and independently.
• Experience with recoil-decay tagging is a valuable skill for analysis.
• Solid programming in C++/ROOT.

Responsibilities

• Lead role in detector and ASIC preamplifier tests for SHEXI upgrade of SIRIUS.
• Participate in commissioning the SIRIUS detection system.
• Contribute to activities such as acceptance testing, characterisation of ASICs, digitisers, and installation at JYFL.
• Analyse data and disseminate results via conferences and journals.
• Collaborate with IJCLab, IPHC, GANIL and CEA-Saclay teams.

Skills

Silicon detectors

Electronics (front- & back-end)

C++/ROOT programming

Teamwork

Education

PhD in experimental nuclear physics

Tools

SIRIUS detector system

ASIC preamplifiers

ROOT framework

Job description

Organisation/Company CNRS Department Laboratoire de physique des 2 infinis - Irène Joliot-Curie Research Field Physics Researcher Profile Recognised Researcher (R2) Application Deadline 24 Nov 2026 - 23:59 (UTC) Country France Type of Contract Temporary Job Status Full-time Hours Per Week 35 Offer Starting Date 1 Jan 2027 Is the job funded through the EU Research Framework Programme? Not funded by a EU programme Is the Job related to staff position within a Research Infrastructure? No

Offer Description

The “Spectroscopy Decay Fission” team in the department of Nuclear Physics at the IJCLab, Orsay, seeks a postdoctoral researcher to take a major role in the development of the novel SHEXI detection system. The award of the D-SHEXI ANR grant enables the team to investigate innovative methods to improve the detection efficiency of SIRIUS for L X-rays, enabling the unambiguous identification of the atomic numbers of newly discovered superheavy elements.
Additionally, a proposal has recently been submitted to the University of Jyväskylä to commission SIRIUS at the focal plane of the RITU separator. If accepted, the post-doctoral fellow is therefore expected to be off-site for a considerable time during the installation, testing and commissioning runs in Finland. Following successful commissioning, the postdoctoral fellow is expected to propose an experimental program exploiting SIRIUS@RITU.
Finally, the post-doc will be provided with data on 217Pa, already obtained using RITU, to study single-particle energies, residual interactions and E3 correlations beyond 208Pb and address the non-existence of the Z=92 shell gap.
The postdoc will work under the supervision of K. Hauschild and A. Lopez-Martens at the IJCLab and in collaboration with the SIRIUS teams at the IPHC, GANIL and CEA-Saclay. development.

The postdoctoral fellow will take a leading role in the detector and ASIC preamplifier tests required for the SHEXI upgrade of SIRIUS and will participate in commissioning the SIRIUS detection system. Therefore, the successful candidate will contribute to activities such as

• SHEXI silicon detector reception and customer acceptance tests
• characterisation of the XGLab ASIC preamplifiers
• characterisation of digitisers
• the installation and verification of the performance of SIRIUS at JYFL
• verification and update of the online analysis software
• in-beam commissioning of SIRIUS and conducting subsequent experiments
• analysis of these data and their dissemination (conference presentations and journal publications)

The Irène Joliot-Curie Physics Laboratory of 2 Infinities (IJCLab) is an UMR under the supervision of the CNRS (IN2P3), the University of Paris-Saclay. The laboratory is located on the campus of the Université Paris-Saclay in Orsay. The campus is located 20 km south of Paris and easily accessible by RER in 35 minutes. IJCLab was created in 2020 from the merger of five laboratories (CSNSM, IMNC, IPN, LAL, LPT). The staff comprises nearly 560 permanent staff (340 engineers, technicians, and administrators; and 220 researchers and lecturers) and approximately 200 non-permanent staff, including 120 doctoral students. The research themes of the laboratory are nuclear physics, high-energy physics, theoretical physics, astroparticle physics, astrophysics and cosmology, particle accelerators, energy and the environment, and health. IJCLab has very significant technical capacities (around 280 IT) across the major fields required to design, develop/implement the experimental devices necessary for its scientific activity.

Candidates must either already hold, or have obtained before the agreed start date of the contract, a doctorate in experimental nuclear physics.
Candidates must have proven research skills, evidenced by at least one publication as the first or joint first author on a subject or activity related to the project.
Demonstrable knowledge of silicon detectors and their operation is an essential criterion.
Demonstrable knowledge of front- and back-end electronics and their operation is an essential criterion.
The ability to work both in a team and independently will be necessary for a successful commissioning and experimental runs.
Previous experience with the recoil-decay tagging technique will be a valuable skill for analysing the experimental runs. As well as a solid level of programming in C++/ROOT.