The current stored in Sirius's accelerators has increased from 100 mA to 200 mA, the result of a period of maintenance activities that involved installing new components including two superconducting radiofrequency cavities. This change represents a major advance in beamline research capabilities at Sirius.
The current upgrade takes place alongside a significant change in operations from March 2023, when Sirius began to run in "top-up" mode, ensuring that current remains nearly constant throughout operations. This continuous mode increases the number of photons emitted per day and provides more stability for the accelerator components and the beamlines.
Installation of the two superconducting radio frequency cavities required integrating advanced subsystems, such as implementing a cryogenic system designed to operate without consuming helium, liquefying the gas in a closed circuit and maintaining ultra-high vacuum levels in the straight sections of the ring where the cavities were positioned. The capacity for high-powered radiofrequency generation also doubled from 120 to 240 kW.
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Commissioning for the cavities included adapting the vacuum for high-power operations, adjusting dozens of control circuits and integrating the new subsystems with those already present in the accelerators (which in many cases were also updated). Despite the complexity and interdependence between the subsystems, the process was completed efficiently within the time allotted.
From now on, Sirius is expected to operate at approximately 200 mA during the periods when the beamline is available to users, twice the current of previous operations. To reach the 350 mA ultimately planned for the project, new facilities will be required. "This increase in current is the result of a proportional increase in the flow of photons to the beamlines, which improves the signal-noise ratio and significantly shortens the time needed for measurements," notes Harry Westfahl Jr., Director of the Brazilian Synchrotron Light National Laboratory (LNLS).
About CNPEM
The Brazilian Center for Research in Energy and Materials (CNPEM) is home to a state-of-the-art, multi-user and multidisciplinary scientific environment and works on different fronts within the Brazilian National System for Science, Technology and Innovation. A social organization overseen by the Ministry of Science, Technology and Innovation (MCTI), CNPEM is driven by research that impacts the areas of health, energy, renewable materials, and sustainability. It is responsible for Sirius, the largest assembly of scientific equipment constructed in the country, and is currently constructing Project Orion, a laboratory complex for advanced pathogen research. Highly specialized science and engineering teams, sophisticated infrastructure open to the scientific community, strategic lines of investigation, innovative projects involving the productive sector, and training for researchers and students are the pillars of this institution that is unique in Brazil and able to serve as a bridge between knowledge and innovation. It is responsible for operating the Brazilian Synchrotron Light (LNLS), Biosciences (LNBio), Nanotechnology (LNNano), and Biorenewables (LNBR) National Laboratories, as well as the Ilum School of Science, which offers a bachelor’s degree program in science and technology with support from the Ministry of Education (MEC).
