First electron beam in the 1.5 GeV storage ring

First electron beam in the 1.5 GeV storage ring

End of September, a stored beam in the 1.5 GeV ring at MAX IV Laboratory was achieved for the first time, thus completing Phase I of the MAX IV project.

– This is one more important mile stone and we are all very happy and proud having being able to deliver results on time, says Director Christoph Quitmann. The 1.5 GeV ring is one of very few modern soft x-ray storage rings in the world. It will serve the large user community already existing in Sweden, but also scientists from around the world.

During the summer shutdown the transfer line, the last piece missing to connect the linac to the 1.5 GeV storage ring, was installed and final subsystem tests were performed. Beam commissioning began early September and will continue well into next year.

– Now the fun starts for us accelerator physicists, says Magnus Sjöström, project manager for the 1.5 storage ring. Apart from the fact that having a stored beam is a necessity for continuing with the commissioning, getting stored beam is equivalent to gaining a very sensitive probe for investigating the machine. There is now a whole range of new measurements possible that will tell us how to calibrate various sensors and magnets, just to name a few. In particular, being able to tune the magnet fields correctly is important to reach the target beam parameters.

– Another important aspect is that with a stored beam we are able to “clean” the vacuum chambers the electrons circulate in. In a new ring the light that the electrons generate will cause the gas pressure to increase by knocking out gas molecules that were stuck on the chamber walls, which then in turn cause us to lose electrons when they collide with the molecules. To get rid of this outgassing we just need to keep enough beam circulating in the machine for long enough. So while this process is not complex, it is somewhat time-consuming and it is therefore good to be able to start.

Soft X-rays, that will be produced at the 1.5 GeV ring, are typically used for spectroscopy which provides knowledge on chemistry and where the components in matter are positioned in relation to each other. It involves methods based on measuring the response that arises in the material when it is illuminated with various types of light.

During the next machine shutdown in 2017, the aim is to install the insertion devices needed to produce light for beamlines. The first beamline that will go into commission is the FinEstBeaMS, funded through an Estonian and Finnish consortium. This beamline will offer several different techniques such as X-ray photoelectron spectroscopy (XPS), photoelectron absorption spectroscopy (XAS) and photoluminescence spectroscopy (PS) for a broad range of materials research.


MAX IV Laboratory consists of three accelerators, a linear accelerator, the 3 GeV storage ring and the 1.5 GeV ring. At present 11 beamlines of 14 that are financed are being constructed or commissioned. In total, the facility can accommodate circa 25 beamlines at the two storage rings and in the extension of the linear accelerator. These beamlines will provide researchers from academia and industry with focused and high-intensity light from ultra violett light via soft X-rays to hard X-rays used in experiment techniques such as imaging, scattering and spectroscopy.

Synchrotrons and X-rays have played a significant role in the advancement of science. From Wilhlem Conrad Röntgen, who was awarded the very first Nobel Prize in Physics 1901 for his discovery of X-rays, up to the Nobel Prize Laureates of this year.

In 1924 the Swedish Physicist Manne Siegbahn was awarded the Nobel Prize in Physics “for his discoveries and research in the field of X-ray spectroscopy”. His son, Kai Siegbahn was one of three Nobel Prize Laureates in Physics 1981 and was awarded the prize “for his contribution to the development of high-resolution electron spectroscopy”. The technique developed is nowadays known as X-ray photoelectron spectroscopy (XPS).

The 2016 Nobel Prize Laureate in Physiology or Medicine, Yoshinori Ohsumi, has done much of his later work in structural biology to understand autophagy, a fundamental process for degrading and recycling cellular components. This kind of research uses X-ray crystallography as an important tool. MAX IV is about to open a beamline dedicated to this kind of research, the BioMAX beamline on the 3.0 GeV ring.

The 2016 Nobel Prize Laureates in Physics, David J. Thouless, F. Duncan M. Haldane and J. Michael Kosterlitz have developed a fundamental mathematical theory initially thought to be quite esoteric. Later it was realised that this theory describes real materials called topological insulators, which actually behave according to the theory proposed by the laureates. One of the main tools for verifying the theory and optimising such topological insulators is angle-resolved photoemission spectroscopy (ARPES) carried out at synchrotrons. Here these fundamental theories have been confirmed and real materials have been optimised with the goal to use them in electronic devices of the future. MAX IV is building a beamline dedicated to this kind of research, the ARPES beamline on the 1.5 GeV ring.

The 2016 Nobel Prize Laureates in Chemistry, Jean-Pierre Sauvage, Sir J. Fraser Stoddart and Bernard L. Feringa, have developed molecular machines and by this addressed fundamental challenges. Applications of these machines are still in the future, but the possibilities for making new smart materials and nano-machines might be as great as when the electric motor was invented in the early 19th century. This kind of research can profit from X-ray techniques. One example is the NanoMAX beamline currently being commissioned at the 3.0 GeV ring of MAX IV.

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