Ph.D. student in radiochemistry studying the chemistry of protactinium in aqueous solution (M/F))

Job Description

Thesis Subject

This project is part of a program dedicated to the fundamental chemical properties of an exotic element, protactinium, in aqueous solution at its two oxidation states (+IV and +V); this program brings together experimentalists (IJCLab-Orsay) and theorists (PhLAM-Lille).
The objective of this thesis is to gain insight into the hydrolysis and condensation of hydrolyzed Pa(V) species, as well as its complexation with inorganic ligands found in the environment (carbonates, phosphates, etc.), through an experimental approach and theoretical chemistry calculations.
The doctoral student will be responsible for developing and validating experimental protocols to overcome Pa(V)'s strong tendency to polymerize in the absence of a strong complexing agent and even in an acidic medium. To determine thermodynamic parameters associated with hydrolysis or complexation, partition techniques (liquid-liquid extraction or ion exchange combined with gamma spectrometry) will be prioritized, using the 233Pa isotope at the ultratrace level.
Based on the speciation data established during the thermodynamic study, the Ph.D. student will prepare samples containing the isotope 231Pa in order to perform X-ray absorption spectroscopy measurements at the L3 and M4 edges of Pa. Due to the instability of Pa in a non-complexing medium at the concentrations required for the spectroscopic measurements, a protocol will need to be developed to stabilize the samples.
The interpretation of experimental spectra will be based on quantum chemistry calculations aimed at determining the geometries and thermodynamic properties of the most stable complexes, using established quantum methodology.

The research will result in publications in peer-reviewed international scientific journals as well as presentations at national and international conferences.

Bibliographical references
Persistent Mono-Oxo Bonding with Protactinium(V) Revealed in Highly Acidic Chloride Solutions. M.Maloubier, T.Shaaban, F.Réal, Naour, H.Oher, T.Aubert, P. L.Solari, B.Siberchicot, R.Maurice, V.Vallet, Angew. Chem. Int. Ed.2026, 65, e18403. https://doi.org/10.1002/anie.202518403

The speciation of protactinium since its discovery: a nightmare or a path of resilience. C. Le Naour, M. Maloubier, J. Aupiais. Radiochim. Acta 2022, 110, 481-493. https://doi.org/10.1515/ract-2021-1126

Scientific, Material, and Financial Conditions of the Research Project
Co-direction and co-supervision for the modeling component: Valérie VALLET and Florent REAL (PhLAM-Lille)
Co-supervision for the experimental component: Melody MALOUBIER (IJCLab)

Your Work Environment

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 RAPHYNEE (RAdiochemistry and PHYsics for Nuclear Energy and Environment) group of the Laboratory which which, among other things, conducts fundamental research on the chemistry of actinides in solution. The group includes 6 permanent researchers and associate professors, 1 research engineer, 2 doctoral students.

Constraints and risks

The PhD is affiliated with the PHENIICS doctoral school at Paris-Saclay University. The position will involve stays of several weeks at the PhLAM laboratory in Lille, as well as travel for synchrotron experiments (SOLEIL, ESRF) or to attend conferences.
The position involves specific requirements related to conducting experiments in an environment subject to regulations governing ionizing radiation. The doctoral student must be authorized to work in monitored and controlled areas and comply with applicable rules regarding radiation protection, safety, and security. The necessary regulatory training will be provided upon starting the position.
Furthermore, as IJCLab and PhLAM are 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.
Le poste comporte des contraintes particulières liées à la réalisation d'expériences en environnement soumis à la réglementation relative aux rayonnements ionisants. Le ou la doctorant(e) devra être habilité(e) à travailler en zone surveillée et contrôlée et respecter les règles applicables en matière de radioprotection, de sécurité et de sûreté. Les formations réglementaires nécessaires seront assurées dans le cadre de la prise de fonction.

Compensation and benefits

Compensation

2300 € gross monthly

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