University of Tartu researchers help fusion scientists bring the sun to the earth


It is said that nuclear fusion to produce energy is always 20 years away from us. Fulfilment of this dream would metaphorically bring the sun to the earth and as a result, people could forget energy crisis for good. Production of electricity by means of nuclear fusion is desirable because compared to modern nuclear power plants, its environmental pollution would be non-existent and fuel components are abundantly available.

To achieve fusion energy production, efforts are made by several research centres all over the world, including EUROfusion, the European consortium for fusion research. The ultimate objective of EUROfusion is fusion electricity production and this should be possible in the demonstration power plant DEMO, which is in its initial stage of design. DEMO should be able to supply fusion energy to the grid in around 2050. The huge experimental reactor ITER, currently under construction in France, should according to present plans start operation in around 2025. ITER, however, is a research project, not a power plant.

Pointing out how extremely complicated it is to imitate on Earth the fusion of hydrogen nuclei, the nucleosynthesis that takes place on the sun and other stars, French physics Nobel laureate Pierre-Gilles de Gennes said, “We say that we want to put the sun into a box. The problem is, we don’t know how to make the box.”

One of the most critical issues in building the so-called “box”, the fusion reactor, is the radiation tolerance of the materials of reactor components.

“The solar simulator hidden in the reactor is able to effectively activate the turbine, but may at the same time have a devastating effect on all the reactor components that are located near the fusion process,” explained Eduard Feldbach, senior research fellow in materials science of the Institute of Physics.

Photo by Kristjan Jung
Photo by Kristjan Jung

According to Feldbach, building a reactor for electricity production requires materials that are much more radiation-resistant than those we are able to produce today. “Materials scientists need to team up to develop new ideas,” he said.

This is exactly what he has done for several years already with colleagues from the Laboratory of Physics of Ionic Crystals of the University of Tartu Institute of Physics and the Laboratory of Science of Processes and Materials, which belongs to the national CNRS system of France. Together they hope to create highly radiation-resistant optically transparent materials, which could be used in diagnostic devices monitoring the operation of the future reactor.

Such an optical material is to be developed on the basis of the new, so-called spinel nitrides class of materials. In terms of radiation tolerance, materials with spinel structure have a useful feature, their self-healing ability. The idea of self-healing materials may sound like science fiction, but Feldbach says a more precise description would require a whole scientific article.

European fusion research consortium EUROfusion, however, has read all the scientific papers on this subject and believes it is possible to create such new highly radiation-resistant material and use it in the fusion reactor, and has supported the Estonian and French researchers’ work from the measure Enabling Research. “We applied for a total of 540,000 euros for the period of two years to realise our idea, but we do not know yet the exact amount assigned to us. Currently, we have just received confirmation that we have been awarded the grant.”

Enabling Research is one of EUROfusion measures for finding new ideas and technologies. In the close competition in which the Estonian-French joint programme was selected for funding, grants were awarded to 26 more projects. In total, 79 applications were submitted.

Additional information: Eduard Feldbach, UT senior research fellow in materials science, 737 4762,

Original post by the University of Tartu

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