Interview with Johannes Brantl on a model of the Munich Compact Light Source
"Just do it, it's fun!"
During a visit to the Garching ESO Supernova Planetarium and Visitor Center I was fascinated by the model they have there of the European Extremely Large Telescope. As a result, I also wanted to construct a scientific machine. Since I didn't have the fitting bricks at home, I first searched for a software to design the model virtually.
Oh, I was always motivated: I felt completely within my element. We usually started at around 5:30 pm, built for two hours, ordered something to eat and then went on building afterwards, sometimes almost until midnight. 213 hours may sound like a lot, but those hours were distributed among many people and several evenings. A team 18 colleagues from the Chair contributed to the project.
Yes, ever since I was little. The first models were relatively simple. One of the first real Lego models I ever made, when I was four years old, was a police truck. I was very proud of it at the time. At some point I started to build Star Wars models as well. Whenever I had an idea, I tried it out with all the building bricks I had and then refined it. Once the structural core was finished and the shape looked about right, I added the decorative elements.
We use the model to give visitors an overview of the machine and to explain how the Munich Compact Light Source works. In the near future we want to illuminate it with individually controlled LEDs. That would make it easier to show where things are happening, for example, where the electrons are being accelerated.
The MuCLS is like a miniaturized synchrotron, a machine which generates X-ray radiation. Most synchrotrons have giant storage rings a couple of hundred meters in circumference. At the MuCLS this has been reduced to a couple of meters. As a result, the device is significantly more compact, but still generates X-rays with properties similar to those produced at synchrotrons. The maximum energy of the electrons in the storage ring is however considerably lower in the MuCLS than in a large synchrotron.
One doctoral candidate investigated how particles with sizes in the order of micrometers are transported out of the lungs. She used phase-contrast imaging to track the movement of the particles within the respiratory system.
Another example is the investigation of catalysts. Our research group used X-ray absorption spectroscopy to analyze a palladium catalyst to learn more about the electronic and geometrical structures.
The most difficult part was the enhancement cavity, which stores two laser impulses and passively amplifies them. Seen from above, this element looks like an X. A mirror is mounted on each end which reflects the laser beam at an angle of 12.5 degrees. Building the connecting tubes between the mirrors at exactly this angle in such a small space was complicated, especially since I didn't want to put the bricks under any pressure. It took a few attempts before I was happy with this component.
First, I built another, smaller version of the model with about 3,000 pieces. Based on that I then built an even smaller version. The smallest version has the size of a sheet of DIN A4 notebook paper and consists of less than 1,000 pieces. In the future, more scientific setups might follow as models.
Information about the Munich Compact Light Source
Günther, B., Gradl, R., Jud, C., Eggl, E., Huang, J., Kulpe, S., Achterhold, K., Gleich, B., Dierolf, M. & Pfeiffer, F.
The versatile X-ray beamline of the Munich Compact Light Source: design, instrumentation and applications.
(2020). J. Synchrotron Rad. 27, 1395-1414.
Research examples from the interview
Gradl, R., Dierolf, M., Günther, B. et al.
In vivo Dynamic Phase-Contrast X-ray Imaging using a Compact Light Source.
Sci Rep 8, 6788 (2018), doi.org/10.1038/s41598-018-24763-8
Huang, Juanjuan; Deng, Fuli; Günther, Benedikt; Achterhold, Klaus; Liu, Yue; Jentys, Andreas; Lercher, Johannes A.; Dierolf, Martin; Pfeiffer, Franz:
Laboratory-scale in situ X-ray absorption spectroscopy of a palladium catalyst on a compact inverse-Compton scattering X-ray beamline.
Journal of Analytical Atomic Spectrometry, 2021, doi:10.1039/d1ja00274k
About the Munich Institute of Biomedical Engineering
The Munich Institute of Biomedical Engineering (MIBE) is an Integrative Research Institute (IRI) within the Technical University of Munich (TUM). At MIBE, researchers specializing in medicine, the natural sciences, and engineering join forces to develop new methods for preventing, diagnosing or treating diseases. The activities cover the entire development process – from the study of basic scientific principles through to their application in new medical devices, medicines and software.
Zur Munich Compact Light Source
The Munich Compact Light Source consists of an inverse Compton scattering source developed and built by Lyncean Technologies Inc. The X-ray beam line with two experimental end-stations was developed at TUM. The device is used for research projects at TUM.