Prof. Dr. rer. nat. Bastian Märkisch

Courses and Dates

Offered Bachelor’s or Master’s Theses Topics

Development of an Electron Backscattering Detector for PERC

PERC (Proton Electron Radiation Channel) is a new neutron decay facility that is currently being constructed at the FRM II research reactor. PERC is a versatile source of decay electrons and protons and allows the measurement of several correlation coefficients of the neutron decay with an order of magnitude improvement in precision over current experiments. Measurements of these coefficients are a sensitive probe to investigate the mechanisms of the weak interaction.

The core component of PERC is an 8 m long superconducting magnet. Electrons and protons produced by neutrons decaying inside the magnet are guided along the magnetic field lines to the main detector system behind the spectrometer. Our group has previously used scintillator-based electron detectors for precision measurements of neutron decay correlations. Building on this experience, we plan to use similar devices to detect backscattering in PERC. The purpose of these backscattering detectors is to identify events where the decay electron only deposits a fraction of its energy in the main detector.

The objective of this thesis is the design and demonstration of the backscattering detectors for PERC, including the development of a new read-out system for electron spectroscopy with plastic scintillators and silicon photomultipliers (SiPMs).

Tasks

• Familiarize yourself with neutron decay studies and particle-tracking simulations.

• Optimize the design of the backscattering detectors for PERC based on simulation data.

• Develop and test a SiPM-based read-out system for plastic scintillators suitable for precision electron spectroscopy.

• Construct and test a prototype of the backscattering detectors.

What we offer

We offer you an interesting opportunity to participate in the development of a new high-profile experiment, allowing you to gain diverse experiences in the fields of detector physics, electronics, and low-energy particle physics!

suitable as

• Master’s Thesis Nuclear, Particle, and Astrophysics
• Master’s Thesis Applied and Engineering Physics

Supervisor: Bastian Märkisch

Optimization and Test of a Drift-Calibration System for the PERC Experiment

The PERC experiment, currently under construction at the FRM II research reactor, will perform precision measurements of neutron beta decay in search of physics beyond the standard model of particle physics. Aiming to improve the current sensitivity level of neutron decay studies by about an order of magnitude, the experiment requires precise knowledge of the amplification and detection characteristics of its electron detectors. To achieve the desired level of accuracy, we employ a drift-calibration system that monitors the variations in amplification of the photomultiplier tubes used in the detectors. In this thesis, an existing prototype of the drift-calibration system shall be tested and optimized.

Tasks

• Acquire the necessary understanding of photodetectors (photomultiplier tubes, silicon photomultipliers) and learn how to use them.
• Assemble the prototype system and test it under laboratory conditions.
• Implement changes to the mechanical system, if necessary.
• Optimize the control and read-out electronics.
• Help to prepare the system for use in the PERC experiment.

suitable as

• Bachelor’s Thesis Physics

Supervisor: Bastian Märkisch

Struktur der schwachen Wechselwirkung im Neutron-Betazerfall

Messungen zur Teilchenphysik bei niedrigen Energien und hoher Präzision sind in vielen Fällen komplementär und kompetitiv zu Suchen nach neuer Physik bei hohen Energien an Beschleunigern.  Das Instrument PERKEO III ist das führende Instrument zur Untersuchung der schwachen Wechselwirkung im Betazerfall des freien Neutrons.  2019 soll mit PERKEO eine Präzisionsmessung des Betaspektrums am Institut Laue-Langevin, Grenoble, Frankreich durchgeführt werden. Diese Messung  ist sensitiv auf hypothetische Skalar- und Tensor-Wechselwirkungen und wird die Sensitivität um etwa eine Größenordnung verbessern.

Im Rahmen dieser Bachelorarbeit sollen essentielle Komponenten dieser Messung in Betrieb genommen und charakterisiert werden. Dies sind u.a. die beiden Elektrondetektoren inklusive Elektronik und der Apparat zur Energie-Eichung.  Erforderlich sind hierzu experimentelles Geschick und die Bereitschaft sich in ein anspruchsvolles Gebiet einzuarbeiten. Wie bieten einen breiten Einblick über experimentelle Techniken.

suitable as

• Bachelor’s Thesis Physics

Supervisor: Bastian Märkisch