LNLS - Laboratório Nacional de Luz Síncroton

Engineering and Accelerator Division

The Engineering and Accelerator Division is responsible for the operation, maintenance and for the improvements and upgrades of the LNLS synchrotron light source and support facilities. The technical groups of the Division also play an important role in the project and construction of beamlines and experimental stations installed in the light source. The groups are now deeply involved in the design and project of the LNLS new synchrotron light source SIRIUS. Finally, the Division is also responsible for the coordination of new infrastructure projects at the LNLS facilities.

In order to fulfil its large range of activities and face the challenge of designing and building SIRIUS the Division has 14 technical groups connected to the diverse expertises necessary to keep the facility in improved conditions:

• Accelerator Physics: electron optics, beam dynamics, machine upgrades, analysis and evaluation of any machine intervention.
• Beam Diagnostics: beam diagnostics and feedback systems.
• Control: low level control system for the light source.
• Machine Shop: technical support for all groups.
• Magnets: project, construction and characterization of magnets and insertion devices.
• Material sciences: brazing and other welding techniques, new materials.
• Mechanical projects: design and construction of electromechanical components for the light source and beamlines, scientific instrumentation.

•  Operation: light source operation.
• Power Electronics: project, construction and maintenance of DC power supplies.
• Pulsed Power Electronics: pulsed power supplies of the injection system.
• Radiofrequency: project, construction and maintenance of RF systems, high power amplifiers.
• Software Development: software for operation of the beamlines and light source.
• Support in electronics: technical support for the beamlines, interlock system, maintenance of the machine control system.
• Vacuum: design and construction of vacuum systems for accelerators.

 

The Division has also an engineering group in charge of the new projects in general infrastructure (civil, electric, hydraulic, cryogenics) specifically focussed on the peculiarities of the LNLS facilities. The group works in close contact with CNPEM’s Operations Division, responsible for the infrastructure of the whole campus.

Since its inception in 1987 it has been one of the main missions of the LNLS to develop in Brazil the technical expertise to project and construct particle accelerators for the production of synchrotron light for scientific research. The synchrotron light source was designed and built over a period of ten years between 1987 and 1997, when the facility was open to the scientific community with seven operational beamlines. Over the years LNLS has trained qualified personnel in the areas of expertise needed to design, build, operate and maintain the set of particle accelerators and experimental stations that make up the source of light. In order to maintain its competitiveness it is essential that the performance of the source keeps track of the increasing sophistication of the scientific research carried out by users.

As the experiments performed by the users in the beamlines become more and more complex and challenging it is essential to keep the light source in line with the new demands. Upgrades and improvements have been part of the LNLS synchrotron light source’s operational scenario since it started operating as an open facility. These upgrades have considerably improved the range of applicability of the source, either by extending the range of photon energies made available for users or by improving the quality of the photon beam delivered to the beamlines.

The most comprehensive upgrade of the storage ring was undoubtedly the installation of the booster synchrotron in 2002. In order to improve beam orbit stability an overall replacement of the storage ring beam position monitors was carried out in 2008 and 2009. The installation of insertion devices – special magnets designed to extend the photon flux in certain energy ranges – required modifying the machine’s magnetic optics to keep beam lifetime at the same level and simplify operating procedures. Several other small scale improvements have been implemented along these years, the last one being the replacement of the entire klystron-based RF amplification chain by a set of new solid-state amplifiers built in the lab and put into operation in 2010.

The LNLS light source is a second generation machine, meaning that most of its beamlines use the synchrotron light emitted in the dipoles. However, in the few free straight sections between dipoles it is possible to install special magnetic devices called insertion devices. By producing a wiggle in the orbit of electrons, these devices induce the emission of light with different features from those produced in the dipoles, allowing to extend the energy range of the photons and to increase the photon flux in the energy of interest. In this context another major achievement was the construction of the PGM beamline, a challenging undertaking that involved several groups of the Accelerator and Engineering Division and highlighted the importance of tight resource management to carry out complex projects. For this beamline a special insertion device, an EPU Undulator, was thoroughly projected and built at the LNLS workshops and it is now installed in the storage ring. Two other insertion devices are installed in the storage ring, enabling a new class of experiments that were impossible or difficult to perform in the dipole beamlines.

Despite the high reliability and beam stability, the current source has several limiting factors that prevent its use in a large number of applications of extreme importance for future developments in science and technology. Among these limitations are the low energy and the very large size and divergence (emittance) of the electron beam. These limitations have large impact on the brightness of the source, limitations that are impossible to overcome for the current storage ring. The state of the art light sources have very small emittance, operate at higher electron energy and current and use insertion devices as the preferred photon sources for the beamlines. These third generation machines show gains of orders of magnitude in flux and brilliance in the X-ray range compared to the current storage ring.

To overcome these limitations, the technical groups of the Division are now involved in the design and project of the LNLS next light source SIRIUS, a very low emittance third generation machine. The new project presents several technological challenges and will open up a whole range of new research possibilities for the user community.

To know more about the whole range of activities performed in the Division visit the pages of the technical groups. To know more about SIRIUS visit the page of the project.