Is there a molecular accelerator

DESY: On the trail of elementary particles

Status: 18.12.2019 8:01 a.m. | archive
by Irene Altenm├╝ller,

Tiny particles that are accelerated to almost the speed of light and then made to collide. Super-brilliant flashes of light that researchers can use to look into the molecular structure of matter. For many, the processes that take place on the DESY research site in Hamburg-Bahrenfeld are difficult to imagine. The facility with its accelerator tubes, which was founded on December 18, 1959, is one of the world's most important institutions for research into matter today. Scientists from all over the world are looking for the basic building blocks of the world at DESY, deciphering protein molecules or analyzing materials with completely new properties.

In 1959, Federal Minister Siegfried Balke (left) and Max Brauer sign the contract to establish DESY in Hamburg.

It is the starting shot for one of the most important institutions in the world to research the smallest particles: On December 18, 1959, the then First Mayor of Hamburg Max Brauer and the Federal Minister for Nuclear Energy and Water Management, Siegfried Balke, signed a state treaty in the Hamburg City Hall to establish the "German Electron Synchrotron Foundation", or DESY for short. The project is groundbreaking - at that time there were only a few countries with particle accelerators, including the USA. The system will cost 100 million D-Marks, 90 percent will be taken over by the Federal Ministry and ten percent by the city of Hamburg.

In search of the smallest particles

But why all the effort? Researchers had found that there are far more of the tiny building blocks of matter than previously thought. One speaks of a whole "particle zoo". From the end of the 1950s, researchers want to go in search of the smallest building blocks of matter in Germany for the first time. The facility is to be built in Hamburg-Bahrenfeld - on a site that was used in the past as a parade ground and a military airport.

1964: Research in the "particle zoo" begins

It will take more than four years for the huge facility to be operational. On February 25, 1964, shortly before midnight, the time had finally come: a handful of physicists crowded into the control room of the new particle accelerator. The researchers press the key switch - and shortly afterwards they can cheer: the first stream of electrons whizzes through the accelerator's circular vacuum tube around 8,000 times. DESY will officially go into operation soon. The electrons race through the tube at almost the speed of light, large electromagnets keep them in their path. Researchers let the electrons collide head-on when they have absorbed enough energy. The collision creates short-lived particles, tiny building blocks of matter. Detectors make them visible to the researchers.

Further accelerators will follow DESY

The DESY accelerator, which has given the entire research facility its name to this day, is just the beginning. More accelerators were built over the decades - they are called DORIS, PETRA or HERA, with 3.6 kilometers the longest accelerator ring on the site. Today, the development, construction and operation of particle accelerators, along with particle physics and research with photons, is one of the three main research areas at DESY.

The gluon - discovered at DESY

Particle physics, which is dedicated to the question of the internal structure of matter, is the oldest of the three research areas. The researchers achieved a particular success in this area in 1979: At PETRA, the scientists were able to detect gluon for the first time - probably the best-known discovery that DESY has made to date. The gluon is the carrier particle of the so-called strong force. Along with gravity, electromagnetic force and the so-called weak force, it is one of the four fundamental forces of nature. Figuratively speaking, the gluon is a kind of glue that holds the particles of matter together.

Explore the nano world with flashes of light

Materials can be x-rayed with synchrotron radiation. For example, an overpainted Van Gogh painting became visible again.

A third focus at DESY today is research with photons, i.e. light particles. If electrons are strongly accelerated, they give off part of their energy as an intense beam of light. Scientists can use this so-called synchrotron radiation to gain insights into the nanoworld and, for example, to examine molecular structures. Or to "shine through" a wide variety of materials. For example, with the synchrotron radiation from the DORIS accelerator in 2008, an overpainted Van Gogh painting was made visible again - a research success that has also received a wide response in the media.

PETRA is now also used as an X-ray source. Since 2009, scientists have been using PETRA III to generate radiation in the range of hard, very short-wave X-ray light. This light is very intense, sharply focused and flashes in short pulses. Researchers can use it to examine very small samples. Biologists use it, for example, to study the atomic structure of protein crystals.

FLASH - ultra-short flashes of light

With the free electron laser FLASH, a linear accelerator has also been in operation on the DESY site since 2005 - the first in the world to generate flashes of light in the extreme ultraviolet range up to soft, i.e. relatively long-wave X-rays.

DESY in facts and figures

  • Research center of the Helmholtz Association
  • founded on December 18, 1959 in Hamburg
  • Locations: Hamburg and Zeuthen (Brandenburg)
  • Budget: 230 million euros per year, including 211 million euros in Hamburg and 19 million euros in Zeuthen
  • 90 percent financed by the federal government, 10 percent financed by Hamburg and Brandenburg
  • around 2,300 employees
  • around 3,000 guest researchers from more than 40 nations every year

Instead of going in a circle, the particles in the 300 meter long, dead straight system are brought almost to the speed of light by a superconducting accelerator and guided through "undulators" - structures made up of hundreds of pairs of magnets that force the electrons on a slalom course. The particles emit ultra-short, strong flashes of light. Among other things, they can be used to track processes that take place extremely quickly, such as chemical reactions.

Both the measuring stations in the FLASH experiment hall and at PETRA are very popular - only a small part of the worldwide inquiries from research institutions and companies can be served. The system is therefore to be expanded into the new FLASH2020 system from 2020.

European XFEL: The world's longest X-ray laser

The European X-ray free-electron laser European XFEL, which began its scientific operation in 2017, is based on the same principle as FLASH. It is the youngest facility at DESY and the world's largest X-ray laser.

VIDEO: How does the XFEL X-ray laser work? (2 min)

With the help of his X-ray flashes, researchers can decipher the atomic details of viruses and cells, film chemical reactions and take three-dimensional images of the nanocosmos, i.e. the world of cells and molecules. The 3.4 km long, linear accelerator tube runs underground from the DESY site to behind the state border with Schleswig-Holstein and ends there in an experimental hall. Twelve countries participated in the financing of the 1.2 billion euro facility, with Germany and Russia being the largest donors.

On the trail of the Higgs boson

However, particle physics continues to be of great importance to DESY. The Hamburg-based company is involved in research on the Large Hadron Collider LHC, a gigantic ring accelerator with a circumference of 27 kilometers at the CERN research center in Geneva. There, researchers discovered the long-sought Higgs particle in 2012. DESY is also working on the future project International Linear Collider ILC, a linear accelerator which, among other things, is to examine the Higgs particle more closely. However, the final decision as to whether this project will be implemented is still pending.

Ghost particles in the eternal ice

Around 5,160 modules were embedded up to 2,450 meters deep into the clear ice in order to detect so-called neutrinos.

Another spectacular project in which DESY is involved is called Icecube: Researchers have embedded more than 5,000 detectors up to 2,450 meters deep into the eternal ice of Antarctica. They serve as a huge telescope to track down so-called neutrinos. These extremely light particles usually fly through all matter unhindered and are therefore also called ghost particles. Only very rarely do they collide with particles of matter and can be observed in this way. In Antarctica, the researchers are looking for neutrinos that do not come from our solar system, but from black holes or supernova explosions. They can shed light on these tremendous cosmic events. Twice - in 2012 and again in 2013 - the researchers were able to detect these high-energy neutrinos in the depths of space.

DESY tours

Every 1st Saturday of the month at 10 a.m.
Meeting point:
DESY main entrance
Notkestrasse 85
22607 Hamburg

Registration is requested by phone at (040) 89 98 36 13 or by email at [email protected]

Worldwide important research center

With its three research areas, DESY is now one of the world's most important centers for researching the structure and function of matter. Around 3,000 guest scientists from around 40 nations are using the accelerators to explore the microcosm in all its diversity. Among other things, they test the behavior of novel nanomaterials or observe the course of vital processes between molecules and thus provide important knowledge for the development of drugs and new technologies.

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Hamburg Journal | 11/15/2019 | 19:30 o'clock