Organisation: JGU > Faculty 08 > Institute of Physics > Experimental Particle & Astroparticle Physics (ETAP) > AG Oberlack
Research: JGU > Faculty 08 > Physics > Astro-, Astroparticle & Neutrino Physics > AG Oberlack
Welcome to the web page of the Oberlack Group at the Johannes Gutenberg-Universität Mainz. Below you find an overview of the different research topics the group works on. Most prominently there are the direct search for dark matter with the XENONnT experiment and the work on COSI — a Compton imager satellite for MeV Gamma-Rays. We also do research and development for a future direct search dark matter experiment and on a Compton Camera for e.g. non-proliferation applications. See below for more details.
If you are interested in a Bachelor’s or Master’s thesis with us, contact Uwe Oberlack or one of the post-docs, in case you want one of us to make an introduction, please get in touch!
The group contributes to the XENONnT experiment, which has at its core a dual-phase time projection chamber and is located in Hall B of the INFN Laboratori Nazionali del Gran Sasso, a laboratory in Italy. The experiment uses 5.4 tonnes of liquid xenon as a scattering target to search for Dark Matter, for example the Weakly Interacting Massive Particle. Click “Learn more” for further information on Dark Matter, the experiment and its technology as well as the contributions of the Mainz group.
The soft/medium gamma-ray regime is the least astrophysically explored range across the electromagnetic spectrum. The sensitivity of current missions is orders of magnitudes worse than neighboring bands due to high instrumental and atmospheric backgrounds, low interaction cross sections and inherent difficulty of imaging at these energies. It remains an extremely interesting range harboring the positron annihilation line, signatures of stellar nucleosynthesis, emission from the most extreme environments and multi-messenger astrophysics. In our group we work on the Compton Spectrometer and Imager (COSI) – a mission which is dedicated to explore this energy range.
The MainzTPC is our local, dual-phase TPC with an inventory of about 300 g of liquid xenon. We use it to develop technology for future dark matter detectors. Right now we are upgrading its readout using Silicon Photomultipliers and are revamping how we fill and level the TPC.
After the upgrade, the goal is to deploy the TPC to measure the Migdal effect in xenon.
As a XENON and Darwin member the group is involved in the effort to develop the next generation xenon filled dual-phase time projection chamber. Together with the colleagues (and competitors) of the LZ collaboration, XENON and Darwin collaborators have formed the XLZD collaboration. Find out about our work towards the ultimate xenon filled Dark Matter observatory, by clicking on “Learn more”.
Here will follow a short description of the XeLIPs project and a link to more information.
(Scintillation detector-based Localization and Characterization of Radioactive Material)
With partners at Hellma Materials, Brenk Systemplanung, Fraunhofer Institut für Naturwissenschaftlich-Technische Trendanalysen (INT) and Julius-Maximilians-Universität Würzburg, we plan to apply scintillation-based Compton cameras and spectrometers for the decommissioning of nuclear power plants. Our group, with support of the PRISMA Detectorlab, will develop a Compton camera with CeBr3 and plastic scintillators of high spatial resolution, using SiPM arrays for readout and custom-built electronics. If successful, such technologies might also become relevant for the sorting and characterization of radioactive waste. Similar technologies are being discussed for the calorimeter of space-based Compton/pair telescopes such as newASTROGAM.
We are developing a Compton camera based on position-sensitive scintillation detectors for use in the decommissioning of nuclear power plants. A combination of modules of plastic scintillators and CeBr3 crystals read out by silicon photomultiplier (SiPM) arrays will provide sub-cm position resolution and fast timing.
All publications, including Bachelor’s and Master’s theses, as well as PhD theses and conference contributions you can find at the “All publications” link on the right. Below you can find our 10 most recent papers.
Shumit Mitra et al 2026 JINST 21 P01034
2026
Alexander Deisting et al 2026 JINST 21 P01033
2026
Savitri Gallego et al 2025 ApJ 986 116
2025
Aprile, E., Aalbers, J., Abe, K. et al. (XENON collaboration), Eur. Phys. J. C 85, 695 (2025).
2025
E. Aprile, J. Aalbers, K. Abe et al. (XENON Collaboration), Phys. Rev. D 111, 103040
2025
E. Aprile, J. Aalbers, K. Abe et al. (XENON Collaboration), Phys. Rev. Lett. 134, 161004
2025
Aprile, E., Aalbers, J., Abe, K. et al. (XENON collaboration), Phys. Rev. Lett. 134, 111802
2025
Aprile, E., Aalbers, J., Abe, K. et al. (XENON collaboration), Phys. Rev. D 111, 062006
2025
M. Adrover, L. Althueser, B. Andrieu et al. (DARWIN Collaboration), Eur. Phys. J. C 84, 88 (2024)
2024
Lommler, J.P., Gerd Oberlack, U
2024
In due time, we will add more specific offers for Bachelor’s and Master’s thesis as well as HiWi opportunities. Until then, you can always get in touch with us – we have always exciting research projects for interested students and most of the time we have HiWi opportunities as well.
In the group we offer Bachelor’s and Master’s thesis on the research topics listed above. To be more specific, topics include:
- Hardware/ Instrumentation
- Simulations
- Electronics
- Data analysis
Feel free to reach out to Prof. Oberlack and/or another group member for an initial discussion what could be possible!
The aim of this advanced lab-course project is to take interested students through the process of setting up working detector simulation using GEANT4 and general Monte-Carlo techniques and deriving detector performance estimates in the context of direct dark matter detection. Thus, the learned techniques are also applicable to a wide variety of other experiments, not only the ones we work on in the group.
Interested students should possess some basic knowledge of object-oriented programming, intermediate knowledge in coding, and at least basic knowledge of C++. Prior exposure to detector physics is helpful but not mandatory.
The project is intended for small groups of 2 students. The timescale of the project is two weeks of implementing the simulation in our group followed by another two weeks for the analysis tasks. It is highly recommended to use the lecture-free period for the project.
Check the link to the left for more information and to see whom to contact!
On an irregular basis we have a lunchtime journal club, during which one person presents a paper they found interesting. (Which is not necessarily connected to the research of the group.) The event is group internal, but if you like to get to know the group in an informal setting over lunch and learn about a science topic, you are welcome to join! Get in touch to find out when we’ll have the next journal club.
For general inquiries regarding open research positions please contact jobs-grp-oberlack@uni-mainz.de
