PETRA III

PETRA III. It is a world-leading, third-generation synchrotron radiation source located at the DESY research center in Hamburg, Germany. As one of the most brilliant storage ring-based X-ray sources globally, it provides extremely intense and focused X-ray beams for a vast array of scientific investigations. The facility enables pioneering research in fields such as materials science, structural biology, chemistry, and nanotechnology, attracting thousands of researchers from across the globe annually.

Overview

PETRA III represents a major upgrade of the former PETRA ring, which initially operated as a particle collider for experiments in particle physics, including those contributing to the discovery of the gluon. The conversion into a dedicated synchrotron light source was driven by the need for more powerful X-rays to probe the structure of matter at atomic and molecular scales. Today, it operates as a user facility, providing beamtime to scientists through a competitive peer-review proposal system administered by DESY. Its exceptional beam characteristics, particularly its high brilliance and low emittance, make it an indispensable tool for cutting-edge research, supporting work that has led to advancements in pharmaceutical development, energy storage, and the understanding of fundamental physical processes.

Technical specifications

The storage ring accelerates electrons to an energy of 6 GeV, circulating in a 2.3-kilometer circumference tunnel originally built for the PETRA project. Its brilliance, a key measure of performance, exceeds 10²¹ photons/s/mm²/mrad²/0.1% bandwidth, achieved through the implementation of innovative undulator and wiggler magnet arrays that generate the intense, coherent X-ray beams. The facility features a so-called "double-bend achromat" lattice design, which minimizes the electron beam's emittance, resulting in an extremely small and bright X-ray source point. This design allows for the operation of numerous beamlines simultaneously, each equipped with specialized instrumentation such as high-resolution diffractometers, fast X-ray detectors, and advanced sample environments for experiments under extreme conditions.

Scientific applications

Research at the facility spans a remarkably broad spectrum of scientific disciplines. In structural biology, it is used for macromolecular crystallography to determine the three-dimensional atomic structures of proteins, viruses, and ribosomes, aiding in drug design for diseases like COVID-19. Materials science experiments investigate novel superconductors, catalysts for green chemistry, and the microstructural properties of advanced alloys. The high flux enables X-ray scattering techniques to study the dynamics of soft matter, such as polymers and colloids, while X-ray imaging and tomography provide non-destructive insights into fossilized specimens, archaeological artifacts, and functional materials for battery technology. Furthermore, its beamlines support research in geophysics, environmental science, and quantum materials.

History and development

The original PETRA ring began operation in 1978 as one of the world's first major electron–positron colliders, where experiments by the TASSO and JADE collaborations provided crucial evidence for the existence of the gluon. After the conclusion of its high-energy physics program, the ring was used from 1995 to 2007 as a pre-accelerator for the HERA collider. The decision to transform it into a premier synchrotron light source was made in the early 2000s, with a major upgrade commencing in 2007. This involved installing new magnet systems, constructing a new experimental hall, and building state-of-the-art beamlines. The facility officially started user operation in 2009 and has since undergone continuous improvements, including the addition of the extremely bright "PETRA III Extension" (PETRA IV) beamlines, to maintain its position at the forefront of X-ray science.

Operation and user access

The facility operates around the clock during scheduled user runs, providing beam to approximately 14 specialized experimental stations or beamlines. Access is granted through a merit-based proposal system evaluated by international review panels; successful applicants, from both academia and industry, are awarded beamtime without cost for non-proprietary research. The user community is supported by a team of DESY scientists and engineers who assist with experiment setup, data collection, and analysis. Major research collaborations, such as those within the European Union's Horizon Europe framework, frequently utilize the facility. Its data management systems handle the enormous volumes of data generated, which are often analyzed using high-performance computing resources at DESY and partner institutions like the Max Planck Society.

Category:Synchrotrons Category:Research facilities in Germany Category:Buildings and structures in Hamburg