# Sirius (synchrotron light source)

Sirius is a diffraction-limited storage ring synchrotron light source at the Brazilian Synchrotron Light Laboratory (LNLS) in Campinas, São Paulo State, Brazil. It has a circumference of 518.4 metres (1,701 ft), a diameter of 165 metres (541 ft), and an electron energy of 3 GeV. The produced synchrotron radiation covers the range of infrared, optical, ultraviolet and X-ray light.
Costing R$1.8 billion, it was funded by the Ministry of Science, Technology, Innovation and Communications (Brazil) and the São Paulo Research Foundation. Discussion started in 2008, and initial funding of R$2 million was granted in 2009. Construction started in 2015, and was finished in 2018. The first electron loop around the storage ring was achieved in November 2019. Its first experiments were made during COVID-19 pandemic at MANACÁ beamline, dedicated to macromolecular crystallography.
Sirius is the second synchrotron lightsource constructed in Brazil. The first one, UVX, was a second-generation machine operated by LNLS from 1997 to 2019.

## History

In 2008, LNLS former director José Antônio Brum asked for a preview of a new accelerator, which was then shown to the minister of science Sérgio Machado Rezende. Construction began in 2014 under the Dilma Rousseff government. Sirius is the second operational particle accelerator in Brazil, the first one being the UVX..
The first part of the complex was inaugurated on 14 November 2018 by then-president Michel Temer, and included the main building and two of the three accelerators. The second part included the third accelerator, the storage ring and the commissioning of the first beamlines. Sirius currently operates at 100mA in top-up mode and has 6 beamlines open to external researchers.

## Characteristics

Sirius is used to understand the atomic structure of molecules, which can help in the development of new drugs, new materials used in construction, oil exploration and in many other areas. The 68,000-square-meter building houses a ring-shaped, circumferential 500-meter facility. To protect people from the radiation released by machine operation, designed to be the most advanced of its kind in the world, the whole is shielded by 1 kilometer of concrete walls. Around R$1.8 billion were invested in the project, which makes it the most ambitious scientific project ever made in Brazil.

## Beamlines

Currently, Sirius has 9 operational beamlines, 1 in scientific commissioning, 2 in the assembly phase and 1 the design phase.
| Beamline | Main Technique | Energy Range | Status |
| CARNAÚBA | X-Ray Nanoscopy | 2.05 - 15 keV | Operational |
| CATERETÊ | Coherent and Time-resolsed X-ray Scattering | 3 - 24 keV | Operational |
| CEDRO | Circular Dichroism | 3 - 9 eV | Operational |
| EMA | X-ray Spectroscopy and Diffraction in Extreme Conditions | 2.7 - 30 keV | Operational |
| IMBUIA | Infrared Micro and Nanospectroscopy | 70 meV - 400 meV | Operational |
| IPÊ | Resonant Inelastic X-ray scattering and Photoelectron spectroscopy | 100 - 2000 eV | Operational |
| JATOBÁ | Full X-ray Scattering and PDF Analysis | 40 - 70 keV | Design |
| MANACÁ | Macromolecular Micro and Nanocrystallography | 5 - 20 keV | Operational |
| MOGNO | X-ray Micro- and Nanotomography | 22 | 39 | 67.5 keV | Operation |
| PAINEIRA | Powder X-ray Diffraction | 5 - 30 keV | Operational |
| QUATI | X-ray Spectroscopy with Temporal Resolution | 4.5 - 35 keV | Assembly |
| SABIÁ | Soft X-Ray Absorption Spectroscopy and Imaging | 100 - 2000 eV | Operational |
| SAPÊ | Angle-Resolved PhotoEmission Spectroscopy | 8 - 70 eV | Commissioning |
| SAPUCAIA | Small Angle X-ray Scattering | 6 - 17 keV | Assembly |