PhD student in experimental nuclear physics with a focus on nuclear fission and gamma-ray emission Full-time NEW

PhD Student In Experimental Nuclear Physics With A Focus On Nuclear Fission And Gamma-Ray Emission

Uppsala University, Department of Physics and Astronomy

Are you interested in working with experimental nuclear physics, with the support of competent and friendly colleagues in an international environment? Are you looking for an employer that invests in sustainable employeeship and offers safe, favourable working conditions? We welcome you to apply for a PhD position at Uppsala University.

The research conducted at the Department of Physics and Astronomy encompasses a wide range of physics topics, distributed over nine divisions. The department is located in the Ångström laboratory and employs nearly 400 people, 100 of whom are doctoral students. It offers a broad physics curriculum to undergraduate and graduate students, participation in nationally and internationally leading projects for researchers, and opportunities for partnership with industry and various outreach activities.

The Department of Physics and Astronomy, Division of Applied Nuclear Physics, at Uppsala University conducts research and education in applied nuclear physics. Its activities aim to deepen our understanding of the properties of atomic nuclei and apply this knowledge in areas such as energy and materials research.

The successful candidate will join an internationally active research group investigating nuclear-reaction dynamics and nuclear fission through experiments and modelling. Our research tests theoretical predictions and addresses fundamental questions relevant to nuclear physics and astrophysics. It also produces high-precision nuclear data for applications in nuclear-energy systems, cancer treatment, and radiation-tolerant microelectronics. The group collaborates with leading research facilities across Europe.

This doctoral project forms part of a Nordic collaboration between Uppsala University and the University of Oslo (UiO), within the Norwegian Nuclear Research Centre (NNRC). It brings together expertise in nuclear fission, nuclear structure, gamma-ray spectroscopy, detector development, and nuclear modelling. A substantial part of the experimental work will take place at the Oslo Cyclotron Laboratory (OCL).

Duties

The doctoral project will ultimately investigate how excitation energy and angular momentum are shared between fission fragments and subsequently carried away by gamma-ray emission. You will measure prompt fission gamma-ray spectra, multiplicities, and total energies as functions of excitation energy, and attempt to extract fission-product yields and isomeric yield ratios. These measurements will test our understanding of nuclear fission and provide data to improve predictions of gamma-ray heating and other fission observables relevant to Generation IV reactors operating with fast neutron spectra.

You will prepare and conduct experiments at OCL in close collaboration with researchers and technical specialists at UiO. The experiments will use the uranium-235(d,pf) reaction as a surrogate for neutron-induced fission of uranium-235. Detecting the outgoing proton together with fission fragments and gamma rays will allow the measured observables to be related to the excitation energy of the fissioning nucleus.

A central part of your work will be centered around the OSCAR gamma-ray detector array, charged-particle detectors, and a newly developed fission chamber. You will contribute to detector characterisation, calibration, commissioning, and optimisation of the experimental setup.

You will analyse the experimental data using coincidence techniques, detector-response corrections, background subtraction, and uncertainty analysis. Characteristic gamma-ray transitions will be used to identify selected fission products, while delayed emission will provide complementary information about fragment angular momentum through isomeric yield ratios.

The project also includes computational fission modelling in close collaboration with the nuclear data section at the International atomic energy agency. Using TALYS and fission models such as FREYA and GEF, you will assess how well current calculations describe energy sharing, angular momentum, and fragment de-excitation. Comparisons with the measurements will help identify model limitations and guide further development.

The position involves extended research visits to Oslo and may include detector tests and experiments at other international facilities. You will present your research in peer-reviewed publications, at scientific conferences, and in collaboration meetings.

Requirements

Applicants must meet the general eligibility requirements for doctoral studies through one of the following:

• Hold a Master's degree in physics, engineering physics, nuclear engineering, applied physics, or another subject relevant to the project;
• or Have completed at least 240 higher education credits, including at least 60 credits at Master's level and an independent project of at least 15 credits;
• or Have acquired substantially equivalent knowledge through other studies or professional experience.

The position also requires:

• An interest in physics, experimental work, data analysis, and physical modelling.
• The ability to work independently and systematically, with attention to data quality.
• Good collaboration skills.
• Good oral and written communication skills in English.
• Willingness and ability to undertake research visits abroad, particularly to Oslo, and participate in experimental campaigns and scientific conferences.

Additional qualifications

Desired qualifications that will be used in the ranking of the candidates:

• Good knowledge of physics, including nuclear physics and radiation detection.
• Programming experience, for example in Python or C++, and an interest in developing your scientific-computing skills.
• Gamma-ray spectroscopy, coincidence measurements, or nuclear-fission experiments. Radiation detectors, detector electronics, or data-acquisition systems.
• Experimental data analysis using ROOT or comparable tools.
• Monte Carlo simulations of radiation transport and detector response, for example using Geant4.
• Nuclear-reaction or fission calculations using TALYS, FREYA, GEF, or related codes.
• Statistical analysis, uncertainty propagation, or detector-response unfolding.
• Scientific computing involving large experimental or simulated datasets.

About the employment

The employment is a temporary position according to the Higher Education Ordinance chapter 5 § 7. Scope of employment 100 %. Starting date 1 March 2027 or as agreed. Placement: Uppsala

Information about doctoral education, eligibility requirements and admission rules can be found on the web site of the Faculty of Science and Technology.