Doctoral Researcher, Optical and chemical characterization of slow liquid scintillators for the study of neutrinoless double beta decay and rare events

The Department of Physics is seeking a doctoral researcher for Optical and chemical characterization of slow liquid scintillators for the study of neutrinoless double beta decay and rare events starting on 1.1.2027 or as soon as possible thereafter for a period of three and a half years. The reason for the fixed-term period is postgraduate training.

The person we are looking for

The position is part of the Academy of Finland postdoctoral project "Combining detector and nuclear physics for the study of next-generation neutrinoless double beta decay with slow liquid scintillators" (principal investigator: Dr. Mariia Fedkevych, Academy of Finland, 2026–2030). The goal of the project is to create an experimental and theoretical foundation for a future large-scale slow liquid scintillator (slow LS) detector, which can be used to search for neutrinoless double beta decays (0νββ) — a rare nuclear process whose detection would prove that neutrinos are their own antiparticles and help explain the origin of the matter–antimatter asymmetry of the universe. With slow liquid scintillators, it is possible to achieve separation of Cherenkov and scintillation signals, allowing for the capture of topological information of the event in addition to the calorimetric information typical of scintillators.

The doctoral researcher is primarily responsible for the optical and chemical characterization work package of the project, focusing on metal-doped (Mo, Te, Se) slow scintillators. The work is carried out in close cooperation with our international partners at the Johannes Gutenberg University of Mainz and the University of Padua, where the doctoral researcher will spend approximately three months on a research visit for laboratory work and analyses.

The main tasks of the doctoral researcher include:

• synthesis and preparation of slow scintillator samples with varying concentrations of organometallic dopants;
• measurement of optical properties (absorption and emission spectra, decay constants, attenuation lengths) using spectrophotometry and time-correlated single photon counting (TCSPC);
• evaluation of chemical compatibility, long-term stability, and purification efficiency;
• construction of a database of validated optical parameters. This database will serve as direct input for the broader project's Geant4-based optical simulations as well as machine learning-based event reconstruction and classification tools, connecting the doctoral researcher's experimental work to the detector simulation and data analysis efforts.

The student also has the opportunity to participate in accelerator measurements at the INFN Legnaro National Laboratory (LNL, Italy) as well as in scientific publications, project reports, and scientific events.

The doctoral researcher's tasks focus on research aiming for a doctoral degree, postgraduate training, assisting teaching duties, and related other tasks. The tasks, eligibility requirements, and language skills of the doctoral researcher are determined by the university's regulations and language skills in the guidelines (doctoral student). The position requires good oral and written English skills in accordance with the requirements set for the right to postgraduate studies.

The doctoral researcher is required to have a higher university degree and the right to postgraduate studies at the University of Jyväskylä. If the selected applicant does not already have the right to postgraduate studies, it must be applied for via a separate application to the Faculty of Mathematics and Natural Sciences, taking the application period into account. Students in the final stages of their studies, whose master's degree is still in progress at the time of application, may also apply.

We offer

Come and be part of our inspiring and warm community!

At the University of Jyväskylä, you are a valued member of the university community. We do meaningful work and cherish culture. In our multidisciplinary university, you will have the opportunity to influence international research and high-quality academic education. For us, everyone's well-being is important, and we offer excellent facilities on and near the campus for an active and healthy lifestyle.

Remuneration is based on the demanding nature of the tasks and individual job performance in accordance with the university salary system. The task-specific salary part of the doctoral researcher is determined according to the demandingness level 2–4 of teaching and research staff tasks. Your salary at the beginning of the employment will be approximately 2500 euros per month. As the doctoral work progresses, the salary is reviewed in accordance with the universities' collective agreement. The doctoral researcher is required to have a higher university degree.

We offer good working conditions for researchers and follow the principles of the Developing your Researcher Career and Position (HRS4R). The Human Resources Strategy for Researchers (HRS4R) work is based on the values and the code of conduct for the recruitment of researchers in the European Charter for Researchers published by the European Commission (English abbreviation Charter & Code). The University of Jyväskylä is committed to fairness, consistency, and transparency in selection decisions and follows national recommendations for responsible researcher assessment. The University of Jyväskylä is committed to the DORA declaration for responsible researcher assessment and follows the CoARA principles.

Application

Applications must include in PDF format:

• A Curriculum Vitae (CV), prepared following good scientific practice and, where possible, taking into account the CV model (see TENK guidelines).
• A short, free-form application letter (maximum 2 pages) including your research interests, career goals, and previous experience as well as your merits in relation to the suitability for this position.
• A degree certificate (highest degree).

We expect your application in our recruitment system no later than 30.9.2026.

For more information, contact academy researchers Mariia Fedkevych ( mariia.m.fedkevych@jyu.fi ) and Kai Loo ( kai.k.loo@jyu.fi ).

Our application process is transparent, professional, and international. We inform applicants openly about the progress of the process at its various stages. We value equality and diversity in our working community and encourage all qualified applicants to apply.

The application begins on August 4, 2026, and ends on September 30, 2026, at 23:59 (Europe/Helsinki).

Department of Physics

The main research areas of the Department of Physics are nuclear physics, particle physics, and materials physics. The research areas of nuclear physics include nuclear astrophysics, nuclear structure physics, and applied research using accelerators. In particle physics, the focus is on the strong interaction, ultra-relativistic heavy-ion collisions, neutrino physics, and particle cosmology. The research areas of materials physics are nanomaterials and thin films, quantum materials and quantum technologies, light-matter interaction, and nanoparticle properties. Experimental research is conducted in the department's accelerator laboratory, the multidisciplinary Nanoscale Science Center laboratory, and in foreign research centers such as CERN. From January 2026, the department will host three excellence centers funded by the Academy of Finland: the Quark Matter Excellence Center, the Quantum Materials Excellence Center, and the Neutron Star Physics Excellence Center.

In the human-centered community of the University of Jyväskylä, with 2,800 experts and 14,500 students, it is easy for everyone to find their place. It is important to us that our community members are well and have opportunities to grow and develop. Our beautiful park campus is located in the center of Jyväskylä. As a university, we are a smoke-free and scent-free workplace, and we are the third largest employer in Central Finland.