Text: José Tadeo Arantes | FAPESP Agency
With a circumference of 530 metres, Sirius, a fourth-generation synchrotron light source, is the largest and most important scientific infrastructure in Brazil. It is also one of only three devices of its class actually in existence in the world. The other two are in Sweden and France, respectively, while countries that are very advanced in research, such as China, are still building their own facilities. Light from Sirius emits in different bands of the electromagnetic spectrum, from infrared to X-rays, and penetrates a wide variety of materials, making it possible to study their structure and composition.
Sirius is located in the National Center for Research in Energy and Materials (CNPEM), in Campinas, funded with resources from the Ministry of Science, Technology and Innovation (MCTI), and is an open infrastructure that can be used free of charge for scientific research. of public interest or when paid in commercial surveys of special interest.
To talk about this equipment, whose range of applications, in progress or potential, is enormous, FAPESP brought to the physical hall Harry Westphal Jr, director of the National Synchrotron Light Laboratory (LNLS), where Sirius is installed. It is possible to attend the “Fourth FAPESP Conference 2023: Sirius: A New Era for Brazilian Science with the Fourth Generation Synchrotron”, presented on Friday (25/10), channel from FAPESP Agency on YouTube.
Westfahl Junior has announced that the third regular call for research proposals for the first ten Sirius pilot stations is now open. Brazilian, Latin American and Caribbean researchers can Presentation of projects until September 6th. Those who have accepted the proposals can request financial assistance for the use of the facilities and for the trip to Campinas.
In addition, it has embodied the possibilities of using each of the ten light lines already open for regular tenders or in operation (four more are under construction). Results range from visualizing the active sites of proteins, and how electrons move from or to them through oxidation or reduction processes, to studying materials exposed to extreme conditions of temperature, pressure or magnetic field, which pass through for a new presentation. Physical or chemical properties, such as in superconductors, that are capable of conducting electric currents without resistance.
An important difference between the research done at synchrotron beamlines is that they allow experiments On sitevisualizing the changes that occur in the structure of materials when they are subjected to various parameters of temperature, pressure, mechanical stress, electric or magnetic fields, different chemical environments, etc.
New light lines
The four new beamlines now receiving research proposals in this call expand the experimental possibilities of Sirius. According to Westfahl Júnior, other types of experiments can be carried out, complementing the existing ones: “In the Sedro beamline we will open up new possibilities for conducting experiments for biophysical research, while in the Sabia beamline we will have more possibilities to reveal the mechanisms that give magnetic properties to materials Mahogany, the highest-energy beamline on Sirius, will open up unprecedented capabilities in X-ray tomography, benefiting many areas of knowledge.The Paineira line will expand our capacity for crystallography, unlocking the possibilities of mineralogy and the study of the atomic structure of catalysts in real time actual.
In addition, the Epibee beamline, already open for research, now introduces a new technology, resonant inelastic X-ray scattering (RIXS). “It is a technique available in only a few synchrotrons in the world, which makes it possible to demonstrate how electrons are organized to confer the properties of catalytic centers in biomolecules to form exotic states of matter, as in superconducting materials,” he explained.
particle accelerator
Sirius is basically a particle accelerator. Westphal Jr. explained the difference between it and other accelerators, such as the Large Hadron Collider (LHC), installed on the French-Swiss border. At the LHC, two beams of hadrons (mainly protons) travel through the equipment in opposite directions. After being accelerated by magnetic fields to very high levels of energy, they are forced to collide with each other. The chain of formed particles tells us about the configurations of matter that might have existed at these energy levels, validating or improving theoretical schemes such as the Standard Model and allowing us to recreate situations that might have occurred in the primordial universe. The synchrotron accelerator is another.
“Its goal is not to collide. But accelerating the electrons to the speed of light practically produces electromagnetic radiation. When they are accelerated, the electrons emit photons, which are directed by the device into so-called light lines.
Radiation at different wavelengths is filtered and focused on the samples of interest. Depending on the wavelength and the sample, the material may or may not absorb radiation, which reveals its structure and composition. “Visible light has an energy of about 2 electronvolts. But Sirius produces radiation that ranges from values much smaller than an electronvolt to much larger than thousands of electronvolts.
Low energies, in the infrared range, make it possible to identify the ‘fingerprints’ of chemical bonds. Energies slightly higher than that of visible light make it possible to study how electrons are arranged in materials. And energies much greater than thousands of electron volts, especially in the X-ray range, open windows for a wide range of experiments.
All technology is used to condense electrons and produce the smallest possible beams, in order to make mapping of matter on the nanometer scale possible. “In fourth-generation synchrotron accelerators, the beam size is much smaller than in previous generations. The coherent part is much larger. Exploring this coherence is what gives us so many new possibilities. Another important aspect is that it is not enough to produce a small electron beam. This beam also has to be stable, so that it can spin through the accelerator all day, all week, and not change more than a few hundred nanometers.”
An example of collaboration
The Westfahl Júnior exhibition group and Q&A session provided an extremely diverse range of information about Sirius, from the physics of synchrotron radiation to the profile of researchers and technicians involved in the equipment, from funding values to terms of submission proposals for use, from openness to foreign teams to the diplomatic capital it provides This research infrastructure of the country.
The conference was opened by the general manager of FAPESP, Carlos Amerigo PachecoWhich highlighted the role of the pioneers in building the first synchrotron accelerator in the country and the contribution of the national industry in manufacturing its components. And he managed it Oswaldo Bava Filho, from the Faculty of Philosophy, Sciences and Letters of Ribeirao Preto, University of São Paulo (FFCLRP-USP). Present in the audience is the President of FAPESP, Marco Antonio ZagoHe attributed the project’s success to a rare example of collaboration between the scientific community, private companies, and the government.
Very detailed information about Sirius can be obtained from outlet from CNPEM.
More information about this and other events in the “FAPESP 2023 Conferences” series is available at: fapesp.br/conferencias2023.
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