Faculty of Mathematics, Physics
and Informatics
Comenius University Bratislava

A Unique Ion Analyzer

A unique ion analyzer installed in the framework of the ACCORD project in the FMPI CU.

28. 02. 2023 22.03 hod.
By: Pavel Povinec

A unique high-energy ion analyzer for accelerator mass spectrometry (AMS) of isotopes was put into operation in the Center for Nuclear and Accelerator Technologies (CENTA) of the Department of Nuclear Physics and Biophysics (DNPB) of the Faculty of Mathematics, Physics and Informatics of the Comenius University (FMPI CU), built within the joint project of the Comenius University and the Slovak Technical University "Advancing University Capacity and Competence in Research, Development and Innovation (ACCORD)", co-financed the European Union.  

The analyzer directly analyzes radioactive nuclei as if they were stable, so there is no need to wait for their radioactive decays because the mass of the ions is analyzed directly, not the radiation that arises during the radioactive decay of nuclei (e.g., beta-radiation), which due to their long half-lives is a serious problem. A target, prepared from the investigated sample, is placed in the ion source, from which a beam of studied ions is forwarded to the tandem accelerator, and then, after acceleration and focusing of the beam, the ions are analyzed in the high-energy analyzer. When accelerated ions are analyzed, the background is substantially reduced, so it is possible to determine in the sample already a few tens of investigated radioactive atoms, compared to tens to hundreds of millions of atoms needed in traditional analyses. For example, thanks to AMS, it is already possible to analyze carbon-14 in samples with a weight of around one microgram of carbon, which is a million times smaller than could be analyzed using gas detectors. The measurement time has also decreased significantly from several days or weeks to a few minutes, so that a substantial part of the preparation of the sample (several hours) is taken up. AMS will make it possible to significantly expand the research, especially long-lived radionuclides from tritium through beryllium-10, carbon-14, aluminum-26, chlorine-36, calcium-41, iron-55, strontium-90, iodine-129, cesium-135,137, lead-210, radium-226, protactinium-231, isotopes of thorium, uranium, neptunium, plutonium, americium up to isotopes of curium. AMS represents a revolution in the analysis of isotopes because it allows for research that was not possible before, either because of the low sensitivity of the analytical equipment or because of the necessity to use too large samples that were not available. 

The analyzer, together with the already existing facility for sample analysis using ion beams (Ion Beam Analysis, IBA), built within the EU Structural Funds and in cooperation with the International Atomic Energy Agency (IAEA), will significantly expand the research and use of accelerator technologies in natural, biomedical, technical, and humanitarian sciences, from astrophysics to archaeology. Among the most important applications will be climate change studies (Milankovitch cycles, variations in solar activity, past volcanic eruptions), space weather research (solar eruptions in the past, possible impacts on terrestrial infrastructure and space flights), the use of radionuclides as tracers of natural processes in the atmosphere-biosphere and atmosphere-hydrosphere (ocean) ecosystems, investigations of radioactive pollution of the environment from the operation and accidents of nuclear power plants, investigations of rare nuclear processes and decays, including the search for dark matter particles, nuclear reaction studies for astrophysics and thermonuclear physics, investigations of radioactive contamination of new generation of materials, modifications of properties of materials after their irradiation at the accelerator, research on damage to DNA and living organisms after their irradiation with ionizing radiation, research on degenerative changes in the brain of patients suffering from Alzheimer's and Parkinson's disease, investigations of the authenticity of works of art (paintings, statues), radiocarbon dating of samples from important archaeological sites in Slovakia, and in many other applications. 

Much of this research will be possible thanks to terrestrial isotopic archives (tree rings, ice-core samples from deep boreholes, stalagmites/stalactites, freshwater and marine sediments, etc.), but also thanks to extraterrestrial archives (meteorites, lunar samples and in perspective also rock samples from Mars), because some of them store isotopic information from thousand years to hundreds of millions of years. Broad domestic and international cooperation, including joint scientific projects with the participation of students, PhD students, and postdocs, will be a necessary prerequisite for successful research in such a wide range of scientific programs. 

The built accelerator center, including AMS and IBA technologies, supplied by National Electrostatic Corp. (USA) a KVANT s.r.o., together with low-background gamma spectrometry, which has been a traditional research program at DNPB for about fifty years, will belong to the unique laboratories engaged in accelerator technologies and in radioactivity studies of terrestrial and extraterrestrial objects.