Low and Medium Energy Physics F2


Research departments
Administration and support units


Our researchers perform a basic and applied research in the low and medium energy physics. The first is relates to the work in the atomic physics while the second contributes to the knowledge of the nuclear physics. We deal with radiological environmental protection mainly concerned with the monitoring of environment in the vicinity of nuclear power plant and with the monitoring of the radioactivity in the food. A mobile ecological laboratory is a part of our Department, besides the other three laboratories:

In atomic physics we perform experiments to test new model approaches, while the phaenomena, which are already fairly well understood are used to set-up and run the analitical methods. The basic research in this area is focused onto the high resolution fluorescence measurements from atomic targets, simple molecules and solids which are performed in the energy and time domain and possibly also in the external nonzero field environment. We do Auger electron-ion coincidence measurements. A near edge structures of different targets with short range order are measured by means of photoabsorption (XANES, EXAFS) and high resolution resonant x-ray Raman processes. Recently a structure of cisplatin was studied, which is an important substance in the cancer chemotherapy. We are regularly engaged in measurements at many European synchrotrons (Elettra, Bessy2, ESRF, Desy).

An ion beam accelerator Tandetron with 2-MV maximum terminal voltage operates at the Microanalytical Center MIC which is in the frame of the department and provides the ion beam current for several analytical methods: PIXE, ERDA, NRA. These methods are used to determine the average elemental concentrations in the bulk as well as the to do the depth profiling and lateral mapping on the um scale with our ion microbeam. Recently, our x-ray detectors were equipped with the polycapillary to set-up for the first time the 3D-PIXE technique. We study aerosol samples, degradation of historical ink manuscripts and do the micromachining with the proton microbeam. M=F6ssbauer spectroscopy is used to study the iron compounds.


  • Nuclear reactions
  • Spin structure and electromagentic structure of hadronic systems
  • Electron coincidence experiments with polarised beams and targets
  • High resolution gamma-ray spectrometry, development of new analytical methods
  • Radioecology and environmental protection
  • Radiological monitoring and control of nuclear facilities, foodstuffs and the environment
  • Maintenance of a national dose-rate standard for radiation protection
  • Calibration of dose and dose-rate measurement equipment
  • Thermoluminiscent personal dosimetry
  • Measurements and modelling of the decay dynamics of atomic systems with photon and ion spectrometry in the time and energy domains
  • Photoabsorption spectrometry, XANES, EXAFS
  • Study of thin films and surfaces with synchrotron radiation
  • Ion (micro)probe analytical methods (PIXE, RBS, ERDA) in vacuum and in air
  • Mössbauer spectroscopy

Departmental web pages

Head of Department
Dr. Primož Pelicon, Asst. Prof., primoz.pelicon@ijs.si

Mojca Gantar
Telephone: +386 1 477 34 12
Fax: +386 1 477 31 51

Fundamental research in nuclear physics is carried out within the Hadron Systems Structure group. At the MAMI laboratory, (Mainz, Germany), Jefferson Lab (Newport News, USA) and the MIT-Bates (Boston, ZDA) laboratory the group's memebrs participate in the planning, execution and analysis of coincidence experiments with polarised electron beams and polarised targets. At the iThemba LABS in Cape Town, South Africa, we have recently carried out high-energy gamma-ray measurements with the AFRODITE HPGe detector array in order to study radiative nuclear capture of protons on a 208-Pb target. This was a world's first spectroscopic measurement of 20 Mev photons with high resolution detectors. The resolution was improved by a factor of more than 10 with regard to earlier measurements.

Our Laboratory for Radiological Measurement Systems and Radioactivity Measurements (LMR) is a leading one of its kind in Slovenia and carries out an extensive environmental monitoring program around the Krsko nuclear power plant, whithin the framework of which about 700 samples of water, air, foodstuffs and soil are taken from the plant itself and above all from the surounding areas on a yearly basis in order to determine the specific activites of natural and artificial radionuclides in them and to arrive at a comprehensive assessment of the radoilogical impact of the NPP on the local population and environment. Two similar, but less extensive programs are run on the entire area of the country as well. We also perform gamma-ray spectrometry and liquid scintillation measurements of samples for the indistry and other interested clients. An important part of our activitiy is also research in both methods, with the emphasis of the introduction of the newly devised approaches into everyday practice. We keep constant track of our performance and maintain our proficiency through regular participation in national and internatioal intercomparison exercises.

The LMR laboratory also mantains and runs a mobile radiological unit, equipped and regularly trained for speedy intervention in emergency situation. The unit carries out interventions on a need-to basis, but maintains its operational capability by participating in national and international exercises several times a year.

The National Laboratory for Dosimetry Standards (NDS) was officialy nominated in 2004 by the Slovene Metrology Offfice as the keeper of the Sovene national reference standard for quantities used in radiation protection. The activities of the Laboratory within the Slovene metrological network concentrate on the maintenance of tracebality of secondary radiaiton standards and calibration of personal dosimeters, as required by national and international legislation on the radition protection of radiation workers. In addition to the routine calibration services offered to internal and external customers, research is carried out by the laboratory in radition metrology.

The Laboratory for Thermoluminiscent Dosimetry caters to the needs of internal and external customers in personal and environmental dosimetry and carries out research in the field of radition detection and measurement.

J. Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia, Telephone: +386 1 477 39 00, Fax: +386 1 251 93 85