Vienna (ABC Live): Hydrogen Fusion : A recently completed coordinated research project (CRP) has improved the understanding of fundamental atomic and molecular processes necessary to progress in the development of fusion as a future source of energy. Specifically, the project generated and evaluated data for collisions of hydrogen and helium and the resulting radiative processes, in which energy is released in the form of electromagnetic radiation. Fusion reactions can be induced in a form of matter called plasma, which consists of extremely hot electrically charged gases, and which was the focus of the research.
“The data from this CRP have expanded our capability to simulate the complicated processes that go on in fusion devices, giving us a clearer picture of what’s happening in our experimental reactors,” said Bastiaan Braams, a researcher at the Netherlands’ National Research Institute for Mathematics and Computer Science (CWI), which participated in the CRP.
Nuclear fusion, the reaction that powers the Sun, has the potential to eventually provide a virtually unlimited supply of clean, carbon-free energy using water and lithium as fuel. However, harnessing commercially-viable fusion power involves serious technological challenges, including protecting the wall of the reactor vessel at extremely high temperatures and controlling the fusion reaction – areas that the CRP helped to address.
This project studied collisions and reactions of hydrogen and helium in fusion devices, but primarily dealt with reactions of hydrogen, including its isotopes deuterium and tritium and their various molecules and molecular ions. This helped the researchers move towards developing a database of critically-evaluated collision cross sections (i.e. how close together particles need to get in order to induce a collision) and reaction rate coefficients (i.e. measurements of the speed of a chemical reaction). This in turn will enable researchers from around the world to perform calculations more easily and with higher precision.
This CRP, which involved researchers from institutions across 12 countries in collaboration with the IAEA, has generated crucial data that will help scientists create modelling tools to simulate hydrogen atoms and relevant molecules in fusion related conditions.
How does controlled fusion work?
In the core of the Sun, fusion reactions between hydrogen atoms take place within dense plasma — the process powers our home star and makes it shine. These reactions require incredibly high energies to convert tiny amounts of mass into vast amounts of energy (according to Einstein’s famous equation E=mc2).
Within a fusion reactor, the core reactions require high temperatures, which dissipate rapidly in the outer regions of the fusion chamber, closer to its inner walls. Understanding the physics of this region, the so-called plasma edge, is crucial for protecting the inner walls of the reactor and for controlling the core fusion reaction itself. Part of the technical challenge of controlling fusion for power generation is to model the atomic and molecular processes occurring in the edge plasma. Indeed, even for the simplest of atoms (hydrogen) our knowledge of the quantum processes involved in plasma physics has contained some important gaps.
That rich store of new information will be added to the IAEA’s ALADDIN database of nuclear data, and has already resulted in 68 peer reviewed journal articles. The final CRP publication was published in the journal, Atoms,in May 2017.