Department of Physics and Astronomy

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. Read more on

Uppsala University hereby declares a PhD student position, at the Department of Physics and Astronomy, to be open for application. The PhD-studies will focus on the investigation of the potential risk of radionuclides, specific to the European Spallation Source (ESS), entering the food chain through crops commonly cultivated in the farmlands surrounding the ESS site. 

About the project
Detailed studies will be undertaken to assess the potential radioactive releases from the ESS, a large neutron research facility under construction in Lund, Sweden. The ESS will produce neutrons using a powerful particle accelerator, impinging 2 GeV protons on a tungsten target. The nuclear reactions will also produce many radioactive by-products, such as isotopes of W, Hf, Ta, Gd and Lu. These radionuclides may be released in the environment after a severe accident, and be transferred from soil to plants cultivated in the local farmlands, with potentially harmful health effects.

The project will be jointly conducted by the Ion-physics group at Uppsala University (Sweden), Medical Radiation Physics Malmö at Lund University (Sweden), the Biotechnical Faculty at the University of Ljubljana (Slovenia), and the Department of Low and Medium Energy Physics at the Jožef Stefan Institute (Slovenia). The successful applicant will be based at the University of Uppsala, but is expected to spend time at all institutions involved in the project. The Ion-physics Group at Uppsala University employs beams of swift ions to study their interaction with materials in solid and gaseous forms at an atomic and molecular level. These methods permit the determination of concentrations and depth profiles of atoms and molecules in a material with very high accuracy for samples from biological, environmental and technological contexts. A 5 MV tandem accelerator, a 350 kV high current ion implanter and a Low-Energy Ion Scattering System form the experimental platform. The Environmental Radiology group at Medical Radiation Physics Malmö (Lund University) has extensive experience in the monitoring of radioactivity in the environment via in-situ and laboratory measurements but also through modelling and simulations. The group’s infrastructures include laboratories for the chemical preparation and the analysis of environmental samples by radiometric techniques. The group also has ongoing collaboration on environmental monitoring with the ESS and links to the Lund University research infrastructures (AMS, ICP-MS…). This group will also provide modelling of the radiation doses incurred by the consumption of crops contaminated by accident release from ESS. The Biotechnical Faculty of the University of Ljubljana, the largest Slovenian University, is a public education and research organisation with nine separate departments, together covering numerous life sciences disciplines. Plant growth facility and sample preparation equipment and expertise required for the execution of the project are available at the Department of Agronomy and the Department of Biology, respectively, where all plant material will be processed and prepared for further analyses. The Department of Low and Medium Energy Physics at the Jožef Stefan Institute, the leading Slovenian scientific research institute, manages the Microanalytical Centre where research with accelerated ion beams is conducted. Among ion beam analysis techniques available, micro-particle induced X-ray emission (micro-PIXE) end-station is routinely used to determine distribution of elements in biological tissues in a quantitative manner at micrometre resolution.  In addition, a table-top micro-XRF is available for larger scan areas when poorer resolution (>15 micrometre) suffices. Both apparatus will be used for the detection of elements and their allocation in plant tissues.

Work duties
The project crosses the fields of physics, chemistry and biology in a highly multidisciplinary and collaborative effort, combining sampling in the field, experimental work in the laboratory and modelling.

  • Experiments will be conducted to determine the migration rate of W, Hf, Ta, Gd and Lu through the soil column after ground deposition of these metals.
  • Experiments will be conducted to study the transfer of W, Hf, Ta, Gd and Lu, from the soil to the plant species that are commonly cultivated in the local farmlands.
  • Environmental models will be developed to predict the dispersion of the EES-related W, Hf, Ta, Gd and Lu radioisotopes in case of accidental releases.
  • Estimates of the dose received from food intake by an exposed population will be obtained for different accident scenarios.

Crops common to Southern Sweden (wheat, barley, rapeseed and sugarbeet), will be cultivated in contaminated soil near to the ESS site and harvested for analysis. Soil will be periodically collected from the contaminated site and analysed, to ascertain the migration of the contamination. The same crops will also be cultivated in a laboratory environment in Slovenia and harvested for analysis. The experimental data will be obtained using stable isotopes of W, Hf, Ta, Gd and Lu. Measurements on elemental concentrations in soil and plant samples will be performed by a variety of techniques, including nuclear-microprobe analysis, X-ray fluorescence, synchrotron radiation nano-X-ray fluorescence, scanning electron microscopy and inductively-coupled plasma mass spectrometry. The modelling work will be performed using the software Ecolego, that has already been used for the commissioning of nuclear installations in Sweden, including the ESS.

To meet the entry requirements for doctoral studies, you must

  • hold a Master’s (second-cycle) degree in natural science discipline, or
  • have completed at least 240 credits in higher education, with at least 60 credits at Master’s level including an independent project worth at least 15 credits, or
  • have acquired substantially equivalent knowledge in some other way.
  • be able to demonstrate excellent communication skills;

have excellent study merits; exhibit excellent skills in both oral and written English; be able and willing to travel, both nationally and internationally, on a regular basis.

Due to the emphasis on data collection through both field- and laboratory-work, practical skills will be attributed the highest priority.

Desirable / otherwise meritorious

  • a background in either a Physics or an Environmental Science discipline;
  • a strong interest in interdisciplinary research;
  • strong data analysis skills;
  • past experiences in modelling;

Rules governing PhD students are set out in the Higher Education Ordinance chapter 5, §§ 1-7 and in Uppsala University's rules and guidelines.

About the employment
The employment is a temporary position according to the Higher Education Ordinance chapter 5 § 7. Scope of employment 100 %. Starting date 8 January 2024 or as agreed. Placement: Uppsala

Instructions for application
Applications should include a brief description of research interest and past experience, a CV, copies of exams, degrees and grades, a copy of your Master thesis (or a draft thereof) and other relevant documents. The candidates are encouraged to provide letter(s) of recommendation and contact information to reference persons. 

For further information about the position, please contact: Robert Frost, 

Please submit your application by 16 October 2023, UFV-PA 2023/3312.

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Type of employment Temporary position
Contract type Full time
First day of employment 2023-11-06
Salary Fixed salary
Number of positions 1
Full-time equivalent 100 %
City Uppsala
County Uppsala län
Country Sweden
Reference number UFV-PA 2023/3312
Union representative
  • ST/TCO,
  • Seko Universitetsklubben,
  • Saco-rådet,
Published 13.Sep.2023
Last application date 16.Oct.2023 11:59 PM CEST

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