An Extremely Brilliant Source for the ESRF
The ESRF has recently been upgraded with the “fourth generation” synchrotron light source technology, the project being named Extremely Brilliant Source (EBS). The new ring was switched on in December 2019, and when fully operating will multiply the brightness of the x-rays by 100, illuminating the science of the everyday with unprecedented clarity.
With the launch of the EBS, many of the ESRF’s users will see data collection times drop from milliseconds down to microseconds, and lower. Automated operation of the x-ray instruments will, for example, allow millions of protein crystals to be analysed every month with practically zero human intervention – a truly massive improvement for drug discovery.
As well as increasing the brightness of the x-rays by 100, the new EBS electron storage ring re-uses 90% of the existing infrastructure, has the same footprint as the previous machine, and leaves the existing experimental station layout unchanged. It also has improved energy efficiency, reducing operating costs by around 20%. Alongside x-ray brightness improvements, the beam quality has also been improved giving it laser-like properties and creating an unprecedented tool for the exploration of matter and for the understanding of life at the molecular level.
Kicking electrons with microwaves
Electrons travelling around the EBS ring continuously lose energy as they emit x-rays used for the experiments. As part of the EBS project, thirteen new state-of-the-art radio frequency (RF) cavities have been installed in the storage ring to give the circulating electrons a high energy kick with microwaves on every lap of the ring.
The hundreds of kilowatts of power needed by the RF cavities are supplied from RF microwave sources (Klystrons and Solid state Amplifiers) located outside the storage ring, connected together by a network of several hundred metres of precision welded aluminium waveguides. Waveguides are hollow metal pipes that allow microwaves to travel inside without losing energy and are more efficient than coaxial cables.
Hirsig AG has manufactured most of the waveguides installed initially and then for several upgrades at ESRF since 1990. The last order to Hirsig AG, needed to rebuild the waveguide system for the EBS program contains seventeen meters of straight and bent rectangular tube sections. Aluminium sheets of sections 300mm x 600mm or 150mm x 600mm built from 5mm thick aluminium were precisely machined and welded together in individual lengths up to 2 metres. Each section was terminated by aluminium flanges welded onto the tubes (to allow bolting together) and the flange surfaces were machined after welding to obtain a high flatness and guarantee tight angular tolerances.
The long collaboration between Hirsig AG and the ESRF was mutually beneficial: the Swiss company appreciated the clear directions from the ESRF, and in return, the ESRF were highly satisfied with delivery of components manufactured with outstanding Swiss precision, on time, on budget and to specification.