Thesis topics

 
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The T2K experiment

© Nick Thamm

The T2K (Tokai to Kamioka) experiment studies the phenomenon of neutrino oscillations. It is sensitive to CP violation, i.e. a difference between matter and antimatter, and could thus provide an explanation for why matter and antimatter did not completely annihilate after the Big Bang.

An upgrade of the near detector is currently on its way, the accelerator's beam power will soon be increased and in a few years Hyper-Kamiokande will begin operating as a far detector. For the upgrade of T2K's near detector, new TPCs are being installed to measure neutrino scattering at larger angles. From Aachen we will contribute monitor chambers (see figure) as part of the overall system.

You can participate in the construction, commissioning and testing of these new TPCs! Both Bachelor's and Master's theses are possible. The construction of the monitor chambers will take place in our laboratory in Aachen, the commissioning of the TPC system at CERN and the integration into the near detector at the J-PARC research centre in Japan.

In the field of software, there are tasks in track reconstruction in the new TPCs. Furthermore, we are investigating special final states of neutrino interactions in the T2K near detector.

 

A liquid organic TPC

© Thomas Radermacher

Low-energy neutrinos below 5 MeV are of particular interest in neutrino physics, e.g. for the study of solar neutrinos and geoneutrinos. This also applies to a new concept for monitoring radioactive waste repositories, in which we measure the neutrinos produced by the radioactive isotopes present in the waste.

In this project, a TPC is being developed that uses an organic liquid instead of a drift gas to detect low-energy neutrinos. Unlike liquefied noble gases (e.g. liquid argon TPC), organic liquids do not have to be cooled to low temperatures, but are usually already in the liquid phase at room temperature. An example of such a material where free electron drift has been demonstrated is tetramethylsilane. We are investigating parameters of electron drift in tetramethylsilane, which should lead us to the design of our prototype LOr-TPC.

You can be part of the construction of a prototype detector (see figure) in our laboratory right from the start! But you can also work on the development of a simulation depicting the monitoring of a nuclear repository with the proposed neutrino detector.

 

R&D for gaseous detectors

© Philip Hamacher-Baumann

Our group has extensive experience in investigating the parameters of drift chamber gases, e.g. the variables drift velocity, gas amplification and diffusion. We can perform these measurements between the millibar range and several bar absolute pressure. For this purpose, we have constructed a miniature TPC, a so-called high pressure gas monitor chamber (HPGMC) (see picture). Low pressures can find application in gas detectors for radiation monitoring, high pressures are an interesting option for future neutrino detectors.

We are also performing simulations of the processes in gas detectors and use various simulation programmes for this purpose. One question is, for example, the search for climate-friendly drift gases for future gas detectors. Furthermore, we are investigating so-called micropattern gas detectors, whose function is based on microstructured components.

Measurements and simulations can be carried out within the framework of bachelor and master theses. This can contribute to the design of future detectors in particle physics.