Department of Applied Physics

Nuclear Materials and Engineering (NuME)

The Nuclear Materials and Engineering group employs computational methods to study radiation induced processes and damage formation in materials, including effects ranging from electron excitations to large scale collision cascades involving millions of atoms.
visualization of energetic atoms from a simulation of a collision cascade
Portrait of Andrea Sand

Group Leader

Andrea Sand


Radiation damage in materials

Ever since the work of Marie Curie more than 100 years ago, on the slowing down of alpha particles penetrating sheets of metal, the effects of energetic particles in condensed matter have been the focus of intense research. Particle irradiation is of great technological importance, since it can modify the physical and mechanical properties of materials, for example causing hardening, embrittlement, swelling, and reduction in thermal and electronic conductivity. Such effects are often detrimental to the materials employed in high radiation environments: in nuclear energy facilities and for nuclear waste storage, in particle accelerators, and in space applications. On the other hand, ion irradiation also has the potential to improve material performance, and ion beam modification of materials is used for example in medical applications, and in semiconductor technology.

Despite a century of intense research, major outstanding questions remain in the field of radiation damage in materials. Our work addresses the open question of how electronic excitations affect the formation of radiation damage, through a cross-cutting research program bridging from ab initio calculations to large-scale atomistic simulations, with validation through direct comparison to experiments. We carry out research in close collaboration with colleagues at Lawrence Livermore National Laboratory in the US, and at the Culham Centre for Fusion Energy in the UK.


Reactor and radiation physics

In reactor physics, the group partners with VTT Technical Research Centre of Finland Ltd., where the Reactor Analysis team develops state-of-the-art computational tools such as Serpent for the safety analyses of current and future nuclear fission reactors. The VTT team led by Prof. Jaakko Leppänen is strongly involved in teaching of nuclear engineering topics and also provides research trainee positions to our students.

In radiation physics our interests are in the computational methods of gamma-ray spectrometry and identification. SAMPO codes for spectrum analysis and the expert system SHAMAN for subsequent radionuclide identification and quantification have been developed by us. We also belong to the developers of LINSSI database for gamma-ray spectrometry and are active members of the LINSSI Users' Group.

Courses and theses

The Nuclear Materials and Engineering group promotes a few courses and offers positions and subjects for theses.

Introduction to nuclear energy technology

The course is intended for students minoring in energy sciences. It is lectured every spring. The course has three main parts: current, generation II and generation III nuclear reactors, future generation IV fission reactors and fusion reactors. The contents are basics of nuclear physics and technology, nuclear fuel cycle, nuclear waste management, safety and nuclear specific issues. Fusion reactor concepts, basics of fusion physics and material issues are also covered. The course is lectured in Finnish.

Introduction to reactor physics

The course is lectured every autumn. It gives an overall view of nuclear energy, reactors and power plants and an introduction to neutron physics, nuclear reactor theory, reactor kinetics, heat removal, thermal hydraulics, fuel cycles, nuclear waste management and safety viewpoints. The mathematics and physics courses of the first two years are adequate prerequisites. The course is lectured in English.

Advanced course in nuclear engineering

The course is lectured every spring and concentrates on neutron physics. The course introduces a computational chain that can be used to model nuclear reactors. The course covers transport theory, Monte Carlo method, burnup calculation (Bateman equations) and diffusion theory as well as elementary heat transfer and thermal hydraulics. Applications of the computational chain are demonstrated. The course is lectured in English.

Programming course on Monte Carlo particle transport simulations

The course is lectured every autumn and it provides the skills to understand the computational methods used for Monte Carlo particle transport simulations. Monte Carlo codes are widely used as general-purpose calculation tools for particle and radiation transport applications in nuclear engineering, medical physics, fusion and space research. The course topics are focused on neutron transport and reactor physics, but the covered methods also apply to other radiation transport problems. The course is lectured in English.

Experimental reactor physics course

Students who have passed the course “Introduction to reactor physics” can participate in an experimental reactor physics course at the VR-1 reactor in Prague, Czech Republic. At VR-1 we experience in practice many reactor phenomena learned on the theory course. The course consists of a seminar before experiments, a working week at the reactor and a detailed report on one of the experiments. The course is given in spring and its language is English.

Radiation physics and safety

The subject of the course is radiation, its interactions with matter and its health effects. The emphasis is on ionizing radiation, its risks and their mitigation. The concept of risk is studied in connection with radiation and nuclear safety. The course includes laboratory exercises on sealed sources and X-ray equipment. Knowledge of the Finnish regulations on radiation and nuclear safety is provided, and a certificate of a Radiation Protection Officer can be obtained from this course. The course is lectured in Finnish.



The group offers a wide range of subjects for bachelor’s theses, special assignments and master’s theses. Many of our theses are written at the organizations in this field (VTT, Fortum, STUK, TVO) or instructed by their expert personnel.

For further information, please contact Professor Andrea Sand.


Latest publications

More information on our research in the Research database.

Graph theory based approach to characterize self interstitial defect morphology

Utkarsh Bhardwaj, Andrea E. Sand, Manoj Warrier 2021 Computational Materials Science

Deuterium retention in tungsten irradiated by different ions

B. Wielunska, M. Mayer, T. Schwarz-Selinger, A.E. Sand, W. Jacob 2020 Nuclear Fusion

Classification of clusters in collision cascades

Utkarsh Bhardwaj, Andrea Elisabet Sand, Manoj Warrier 2020 Computational Materials Science

Effects of cascade-induced dislocation structures on the long-term microstructural evolution in tungsten

G. Bonny, N. Castin, A. Bakaev, Andrea Elisabet Sand, D. Terentyev 2020 Computational Materials Science

The influence of carbon impurities on the formation of loops in tungsten irradiated with self-ions

N. Castin, A. Dubinko, G. Bonny, A. Bakaev, J. Likonen, A. De Backer, Andrea Elisabet Sand, Kalle Heinola, D. Terentyev 2019 Journal of Nuclear Materials

Radiation damage in tungsten from cascade overlap with voids and vacancy clusters

A Fellman, A E Sand, J Byggmästar, K Nordlund 2019 Journal of Physics: Condensed Matter

Atomistic-object kinetic Monte Carlo simulations of irradiation damage in tungsten

D R Mason, A E Sand, S L Dudarev 2019 Modelling and Simulation in Materials Science and Engineering

Relaxation volumes of microscopic and mesoscopic irradiation-induced defects in tungsten

Daniel R. Mason, Duc Nguyen-Manh, Mihai-Cosmin Marinica, Rebecca Alexander, Andrea E. Sand, Sergei L. Dudarev 2019 Journal of Applied Physics

Heavy ion ranges from first-principles electron dynamics

Andrea E. Sand, Rafi Ullah, Alfredo A. Correa 2019 npj Computational Materials

Collision cascades overlapping with self-interstitial defect clusters in Fe and W

J Byggmästar, F Granberg, A E Sand, A Pirttikoski, R Alexander, M-C Marinica, K Nordlund 2019 Journal of Physics: Condensed Matter
More information on our research in the Research database.

Research group members

Andrea Sand

Assistant professor
Jarmo Ala-Heikkilä

Jarmo Ala-Heikkilä

T304 Dept. Applied Physics
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