Transport in the scrape-off layer (SOL) of a fusion plasma is dominated by plasma filaments, which ballisticly transport energy and particles, where transport codes use a diffusive description of the SOL. The telegraph equation describes ballistic transport like filaments on short time scales, on long time scales the telegraph equation is diffusive. A simplified SOL transport model may allow to interpret SOL diffusion coefficients based on ballistic transport properties. Simple 1D transport models based on diffusive, convective and the Telegraph equations should be implemented and compared to each other.

Contact: Dr. Peter Manz

In dem Feld der Quantensimulation versucht man, z.B. mit Hilfe von supraleitenden Quantenschaltkreisen, schwierig zugängliche, quantenmechanische Systeme nachzubauen, um diese auf ihre Eigenschaften untersuchen zu können. Mit Hilfe dieser Modelle lassen sich dann Rückschlüsse auf das eigentliche System ziehen. Ein Beispiel für ein solches System ist das Bose-Hubbard-Modell. Die zugrundeliegende Wechselwirkung lässt sich auf kontrollierte Weise mit Hilfe von supraleitenden Quantenschaltkreisen untersuchen. Im einfachsten Fall verwendat man dazu man zwei gekoppelte supraleitende Resonatoren, die an ihrem Strommaximum galvanisch miit je einem DC-SQUID verbunden sind. Im Rahmen dieser Arbeit, soll die Messtechnik für die Vermessung so einer Probe verbessert und teilweise automatisiert werden. Hierzu soll ein bereits bestehendes Programm derart erweitert werden, dass die beiden in der Frequenz veränderbaren Resonatoren automatisiert in Resonanz gebracht werden und dort vermessen werden können. Die dabei zu erlernenden Fähigkeiten beinhalten Programmierung in Labview, Datenanalyse mit Matlab, sowie der Umgang mit Mikrowellen- und Tieftemperaturtechnik.

Anforderung

• Ÿ  Abgeschlossenes 5. Fachsemester im Bachelor Studiengang Physik
• Ÿ  Spezialisierung Kondensierte Materie (KM) oder Kern-, Teilchen- und Astrophysik (KTA) sinnvoll

Stand der Wissenschaft und Technik

Lithium-Ionen Akkumulatoren kommen in Handys, Laptops und Akkuwerkzeugen als Energiespeicher zum Einsatz. Die Lebenszeit und Ladegeschwindigkeit dieser modernen Akkus sind allerdings durch physikalische als auch chemische Alterungsprozesse begrenzt, die vor allem an den Elektroden stattfinden.

Aufgaben

Ziel dieser Bachelorarbeit ist es, den Alterungsprozess von Graphit-basierte Elektroden zu untersuchen und die Einlagerung von immobilisiertem Lithium in den Elektroden während des Auf- und Entladens tiefenabhängig nachzuverfolgen, um so die die Alterungsprozesse besser zu verstehen und die Lebenszeit künftiger Lithium-Ionen-Batterien zu verlängern. Im Rahmen der Arbeit werden die Tiefenprofile mit dem N4DP Instrument an der Neutronenleiterhalle des Forschungsreaktors München (FRM II) in Garching vermessen.

Wir bieten

Ein interessantes Arbeitsthema, welches die Materialforschung der Kondensierten Materie mit Grundlagen der Kern- und Teilchenphysik kombiniert.

Hybrid solar cells have promising potential for playing a major role in renewable energy transition. They provide the possibility of flexible and light weighted photovoltaic in a large scale roll-to-roll fabrication, by combining the advantages of organic and inorganic semiconductors. For improved device performance, the morphological structure of the system has a crucial influence. This experimental bachelor thesis aims for a novel approach in templating desired hierarchical structure of the inorganic part, using environmentally friendly, non-toxic biopolymers such as proteins. Thin films of protein/semiconductor composites will be fabricated by spray coating for further structural investigations with the help of scanning electron and atomic force microscopy. Besides the laboratory work, the project also involves a literature review.

Lithium ion microbattery is the type of battery where all components (electrodes, membrane, and packaging) are in the thin film format. The need for such types of batteries is to provide light-weight and shape flexible solid-state energy sources for some miniature medical devices, such as implantable pumps, biosensors, and wireless capsule endoscopes. Membrane based on mixing both lithium slat and polyelectrolyte block copolymers will be prepared and investigated using small-angle X-ray scattering and impedance spectroscopy. The effect of a third component such as inorganic SiO₂ nanoparticles on the morphology and conductivity of the prepared thin film membranes will be studied. The best performing membrane will be assembled between two electrodes to probe the performance of a complete assembly of a solid-state lithium battery. The project will involve a literature review, sample preparation, x-ray scattering and impedance spectroscopy.

The project

Infrared (IR) spectroscopy is used to identify many chemical substances. It is an established analytical method, but it faces one limitation: sensitivity. Measurements with low concentrations can therefore be difficult, which disqualifies IR for certain applications. The TUM start-up IRUBIS is tackling this issue and found that photonic microstructures on the surface of the sample carrier can lead to a signal enhancement. The aim of this thesis will be to analyze how the design of the structures influences this effect.

Your tasks.

• Conducting measurements
• Comparing data and simulation
• Proposing new designs for the photonic structures

What we expect!

• Motivation to work practically on an application-oriented thesis
• A high degree of independence
• Ability to work consistent and precise

What will you learn?

• Simulation of photonic microstructures
• Statistic evaluation of measurement results
• Deep understanding of microstructure fabrication

Interested? 

Send your application directly to Lorenz.Sykora@tum.de, Cc Jonathan.Finley@wsi.tum.de. Please include a cv and a short motivational letter in one pdf file. Starting date: flexible

Thin films of copolymers comprised of a hydrophobic and a thermo-responsive block can act as materials for nanosensors and actuators. When exposed to vapors of water and volatile organic solvents, the films exhibit swelling behaviors that strongly depend on the composition of the surrounding atmosphere. This bachelor thesis will cover the fundamentals of responsive polymers, block copolymer assembly and the co-nonsolvency effect. The experimental part will revolve around thin film preparation, analysis and swelling in mixed vapor chambers. Morphological changes, as well as the development of thickness and refractive index will be investigated via scanning probe microscopy and spectral reflectance techniques. The project will include a brief literature review.

Gas Electron Multipliers (GEMs) are used to multiply incoming electrons to enable the detection of originally small amounts of charge. Thick GEMs (THGEMs) are a robust variation of GEMs. With thickness, hole size, and hole pitch being one order of magnitude larger than in standard GEMs, THGEMs offer more stability against mechanical stress and contamination by dirt. Therefore, they are suited for operation in much harsher environments and form an interesting alternative for a variety of applications.

A novel and innovative method of photodetection is to use a THGEM coated with a material with a low working function (e.g. CsI). Electrons from the top coating are released by incoming photons and can be multiplied by the THGEM for readout. This device offers the possibility for relatively cheap large scale applications, which is particularly advantageous for neutrino detectors.

The student will take part in the coating process of THGEMs and extensive R\&D studies in order to proof the feasibility of this kind of technology.

Weiterentwicklung eines 3-D Druckers

Ein bereits vorhandenes Gerät soll evaluiert und notwendige Verbesserungen sollen integriert werden. Neben Software Modifikationen sind Anpassungen des mechanischen Aufbaues notwendig. Das Projektlastenheft wird gemeinsam erarbeitet.

Kontakt: Rainer Stoepler 089/ 28914272 oder 0162 2944773 rstoepler@tum.de

A fascinating manifestation of spin physics in the solid state are pure spin currents. Their generation and detection is often based on the interconversion of spin and charge currents in ferromagnetic insulator/normal metal heterostructures. The aim of this thesis is the fabrication of high-crystalline thin film heterostructures using reflection high energy diffracton (RHEED) assisted laser molecular beam epitaxy (laser-MBE) as well as electron beam physical vapor deposition. The thin film samples will then be characterized structurally using high-resolution X-ray diffractometry (HR-XRD) as well as magnetically via superconducting quantum interference device (SQUID) magnetometry. By using the best heterostructures, spin Hall magnetoresistance as well as spin Seebeck experiments will then be performed to investigate their spin current properties.
This thesis provides deep insight into thin film technology, laser-MBE, HR-XRD, SQUID magnetometry as well as magnetotransport experiments.  An important aspect hereby will be the fabrication of high-crystalline thin film heterostructures with excellent interface qualities.

Contact: Stephan.Gepraegs@wmi.badw.de, Rudolf.Gross@wmi.badw.de

Perovskite solar cells have dramatically progressed within the last 2 years. Meanwhile championship perovskite solar cells have demonstrated efficiencies above 22%. However, despite the very promising device efficiencies, most fundamental aspects of this class of solar cells are still not well understood. The relation between inner solar cell morphology and efficiency is not for example unclear. Aim is to probe the morphology of differently prepared and aged perovskite solar cells with scattering techniques and establish a structure-function relationship. The project will involve a literature review, sample preparation and measurements of the structure and device characteristics.

The neutron spin echo spectrometer at the MLZ sees more and more proposals with biological samples. These samples have increased requirements with respect to temperature stability and aggregation state control. To meet these requirements a new sample environment has been developed which includes an in-situ dynamic light scattering set-up and a fine temperature control. This set-up should be characterized with respect to its temperature stability and accuracy using test samples based on poly-L-aminoacids of different chain lengths. These test samples should be characterized with light scattering and light absorption techniques with respect to their suitablity as poly-electrolyte samples for Spin-Echo-Spectroscopy. The stiffness of the poly-electrolyte depending on the charge state of the amino-acid side chain is in the special focus of this study.

The TUM group of the COMPASS collaboration at the CERN Super Proton Synchroton specialized in the analysis of high-energy scattering reactions for a better understanding of the strong interaction and the quark-gluon structure of hadrons. The lightest hadron, the pion, consists mainly of light up- and down-quarks and has surprising properties linked to the breaking patterns of chiral symmetry. For the investigation of one of them, the chiral anomaly, a special scattering type has been examined with a charged and a neutral pion in the final state. The neutral pion decays almost promptly into two photons, which are observed in an electromagnetic calorimeter. The analysis of the data depends on a good understanding of this detection, and on the separation of background. In this thesis, the dependence of different background suppression scenarios is to be studied, supporting the analysis for understanding an important aspect of the subatomic structure of matter.

Auslegung eines Reinigers für das Befüllen einer Heliumkälteanlage

Für eine Helium Kälteanlage soll ein Reiniger ausgelegt, gebaut und getestet werden.

Das Projektlastenheft wird gemeinsam erarbeitet.

Kontakt: Rainer Stoepler 089/ 28914272 oder 0162 2944773

rstoepler@tum.de

Gamma-ray bursts (GRBs) are flashes of gamma-rays resulting from either the death of massive stars (leading to long-duration GRBs) or the merger of two neutron stars (short-duration GRBs). Since the discovery of gravitational waves in conjunction with a short GRB in August 2017, the quest of accurately localizing short GRBs is of utmost importance. Present detector technology has it that detectors with good localization capability detect predominantly long-duration GRBs, while those detectors sensitive to short GRBs have bad localization accuracy.

We have developed a concept for a GRB detection system which should provide accurate localisations for short GRBs, and at the same time is small and simple enough to be flown on a swarm of small satellites. The thesis shall take existing GRB data from the Fermi-GBM satellite, and quantify the sensitivity of the new detector concept. In particular, by using methods for the cross-correlation of unbinned light curves of a given GRB as seen in different detectors the requirements for time resolution and effective area should be derived.

Technically, this thesis involves learning of (i) data analysis of non-imaging gamma-ray detectors, (ii) understanding and correcting detector effects, (iii) simulating light curves with different count statistics, and (iv) analyzing the cross-correlation pattern for binned and unbinned data to derive the dependence of the detector sensitivity on the time resolution and effective area.

Some background in astrophysics is advantegeous. Python knowledge is required, and good programming skills and interest in Bayesian statistics are helpful. Joy in data analysis is required.

    Contact: Jochen Greiner, jcg@mpe.mpg.de, MPE Room 1.3.13, Tel. 30000-3847

Gamma-ray bursts (GRBs) are flashes of gamma-ray resulting from the death of massive stars or the merger of neutron stars. They are followed by an `afterglow' signal that can be detected from radio to X-rays, produced by a shock wave moving into the gas surrounding the burster at approximately the speed of light. For both phemomena, prompt and afterglow emission, a huge amount of observational data exists. However, modelling is still mostly done with heuristic functions, like power laws, rather than testing against physical models.

We propose three projects aiming at modeling specific mechanisms of the prompt and afterglow phases of GRBs: the emphasis can be put on  (1) modelling of particle escape from GRB blast-waves, (2) theoretical study of correlations between the time evolution of the polarization state and other spectral observables (peak energy, luminosity etc), or (3) numerical computation of synchrotron radiation from an anisotropic electron distribution function and predictions for circular polarization in GRB afterglow.

Technically, this thesis involves learning about (i) physics of GRB prompt (synchrotron) and afterglow emission, (ii) polarization of synchrotron radiation and Compton scattering, (iii) modelling cross-sections of varous processes, and (iv) deriving predictions against which data can be compared with

Some background in astrophysics is advantegeous. Good numerical and or analytical skills are required.

Contact: Jochen Greiner, jcg@mpe.mpg.de, MPE Room 1.3.13, Tel. 30000-3847

Molecular brushes are composed of a polymer backbone grafted densely by polymeric side arms. In solution, factors that can influence the molecular size and shape include the molar masses of the backbone and the side arms, polymer concentration and temperature.

In this bachelor thesis, a series of molecular brushes, differing in the molar mass of the backbone and side arms, will be investigated in solution. The aim is to determine the dependence of the molecular size on the concentration using dynamic light scattering (DLS).

After a literature research, samples will be preopared and measured, and data analysis will be carried out. For more information, please contact Prof. Christine Papadakis, papadakis@tum.de.

Switchable nanoparticles in aqueous solution can be used for transport and release of drugs or other substances. They may be formed by block copolymers having a  hydrophobic block and a thermo-responsive block. The size and solubility of the self-assembled nanoparticles is controllable by changing the temperature or the solvent composition.

In the bachelor thesis, the main goal is to investigate the phase behavior of novel, self-assembling block copolymers by differential scanning calorimetry (DSC). The effect of both, the chemical nature of the responsive block and the solvent composition will be studied.

After a literature research, samples will be prepared and measured, and data analysis will be carried out. For more information, please contact Prof. Christine Papadakis, papadakis@tum.de.

Abgesehen von der kosmischen Hintergrundstrahlung sagt das Urknallmodell der
Kosmologie auch einen kosmischen Neutrinohintergrund voraus, mit einer etwas
niedrigeren Temperatur. Obwohl dieser bisher nicht direkt nachgewiesen werden
kann, gibt es starke indirekte Hinweise auf dessen Existenz im frühen
Universum. Zu späten Zeiten beeinflussen kosmische Neutrinos die
Strukturbildung. Dieser Effekt hängt von der Summe der Neutrinomassen ab,
die bisher unbekannt sind. Sein Nachweis stellt eines der zentralen Ziele
der nächsten Generation von kosmologischen Beobachtungen dar.

Ziele: In dieser Arbeit wird zunächst die Erzeugung des Neutrinohintergrunds
im frühen Universum basierend auf thermodynamischen und kosmologischen
Argumenten erarbeitet. Anschliessend wird der Effekt des Neutrinohintergunds
auf die Strukturbildung theoretisch modelliert und durch numerische Methoden
der Einfluss auf das Powerspektrum der kosmologischen Dichtefluktuationen
(eine zentrale Observable in der Kosmologie) in linearer Näherung in einem
2-Komponenten-Modell berechnet.

Grundlagen: Statistische Physik und Thermodynamik, KTA, theoretische Mechanik

Methoden: Lösen von gewöhnlichen, gekoppelten linearen
Differentialgleichungen mit numerischen Methoden, Analytische Herleitungen
basierend auf Boltzmanngleichungen und thermodynamischen Größen.

Thermoelectric (TE) materials can be used in TE generators to convert a temperature gradient directly into electrical energy. Therefore they are of great interest in terms of waste heat recovery or the use of solar thermal energy. To be qualified as good TE materials, polymers should have a high Seebeck coefficient S and electrical conductivity σ. In this bachelor thesis polymer films will be post-treated with different methods in order to increase S and σ, leading to a novel efficient TE generator. This project will involve a literature review, polymer film preparation/treatment and TE measurements of the fabricated films.

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.

Um einen Großteil der erzeugten Energie aus erneuerbaren Quellen beziehen zu können, bedarf es effizienter Energiespeicherung zum Ausgleich temporärer Diskrepanzen zwischen erzeugter und verbrauchter Energie. Ein möglicher Lösungsansatz ist die Speicherung von Energie in chemischen Brennstoffen durch photokatalytische Reduktion von CO₂ in energetisch höherwertige Kohlenstoffketten. Ein Hybridsystemen aus molekularen Katalysatoren und Halbleitern stellt einen vielversprechenden Ansatz zur technologischen Umsetzung dieses Konzepts dar. Mit geeigneter Anordnung der Energieniveaus von Halbleiter zu Molekül könnte Ladungstransport zwischen den Systemen stattfinden und die Effizienz im Vergleich zu homogener Katalyse gesteigert werden. Ziel dieser Arbeit ist es, mit Hilfe von Langmuir-Blodgett-Transfer molekulare Monolagen photokatalytisch aktiver Porphyrine auf Galliumnitrid-Substrate aufzubringen und zu untersuchen. Schwerpunkt der Arbeit ist die Analyse des Ladungstransports in Abhängigkeit von der Dotierung des Halbleiters und der Art des Porphyrins mit Hilfe von photoelektrochemischer Charakterisierung.

Kontakt: felix.eckmann@wsi.tum.de

Organic photovoltaics are a promising alternative to conventional silicon solar cells as they offer several potential advantages e.g. low weight, high mechanical flexibility and low-cost production. The chemical structure of the polymer donor and the non-fullerene acceptor molecule as well as their ratio have an impact on the structure and performance of an organic solar cell. Printing of active layers with a slot-die-coating technique enables up-scaling of organic solar cells devices. This experimental bachelor thesis aims at the basic understanding of the printing process and the properties of the active material as well as the construction of an organic solar cell. Active layers are printed with different donor:acceptor ratios and post-characterized by methods such as UV/Vis spectroscopy, optical microscopy and scanning electron microscopy. The project will involve a literature review, sample preparation and post-characterization of the films.

Responsive polymers are water-soluble at low temperatures, but become water-insoluble above a certain temperature, the so-called cloud point, and form large aggregates. Applying pressure, their hydration behavior can be modified, which, in turn, allows controlling their aggregation behavior.

In the bachelor project, the phase behavior and the self-assembly behavior of novel self-assembling thermoresponsive block copolymers shall be investigated under high pressure using turbidimetry and dynamic light scattering.

After a literature research, samples will be prepared and measured, and data analysis will be carried out. For more information, please contact Prof. Christine Papadakis, papadakis@tum.de.

The anti-deSitter/conformal field theory duality is an implementation of the holographic principle. We will first discover the isometries of AdS in 5 dimensions and compare them to conformal group in 4 dimensions. We will then solve a scalar field in AdS and find that certain two point functions resemble the ones of a CFT. 

https://arxiv.org/abs/hep-th/9802150

A superconducting vortex consists of a normal conducting core carrying the magnetic field, screened by a superconducting current. The macroscopic continuity of the wavefunction of the cooper pairs leads to the quantization of flux and renders superconductivity a textbook example of a macroscopic quantum effect. Therefore, superconducting vortices resemble countable, impartible entities that can be assigned with particle-like properties which take over the role as building blocks of a novel kind of matter denoted “vortex matter”. Similar to atoms that condense to a crystal also the superconducting vortices arrange themselves in a vortex lattice which corresponds to a two-dimensional Bravais lattice, reflecting the minimal free energy landscape, where a regular hexagonal symmetry is obtained for isotropic superconductors within the Ginzburg-Landau theory.
Analogous to condensed matter a large variety of phases is also observed for vortex matter. Besides long range ordered vortex lattices, vortex glasses and vortex liquids have been identified. Vortex matter is governed by a multitude of different interactions on the vortices: The energy associated with the expulsion of the magnetic flux leads to a repulsive interaction, while for some superconducting materials, the reduction of energy of overlapping vortex cores can lead to a long range attractive force.
Using neutron scattering, we have carefully examined the phase transitions and domain formation processes of the vortex lattice in the model superconductor Niobium. Topic of this Bachelors thesis is to develop and implement 2D molecular dynamic simulations of superconducting vortex matter. The phase transitions and the domain formation process of the vortex matter shall be simulated considering the various inter-vortex interactions, the presence of pinning and the influence of temperature and magnetic field. The results of the simulations can be directly compared to and fitted to the existing experimental data.
These tasks require both a strong interest in programming and a solid background in condensed matter physics, in particular superconductivity.
The work will be performed together with the SANS-1 team @ MLZ and offers the unique possibility to work at an internationally leading large scale neutron facility like the MLZ.

Contact:
Dr. Sebastian Mühlbauer, sebastian.muehlbauer@frm2.tum.de, 089 289 10784
Alexander Backs, alexander.backs@frm2.tum.de, 089 289 54825

Regulatorische Proteine können ganz bestimmte Abschnitte einer DNA mit hoher Affinität binden. Der molekulare Mechanismus, wie die hohe Affinität und gleichzeitig Spezifität für bestimmte DNA-Sequenzen erreicht wird, ist noch immer nicht genau verstanden. Mit Hilfe von Computersimulationen sollen die Spezifität der Protein-DNA-Wechselwirkung an einem Modellsystem untersucht werden. Dabei kommen Methoden der Berechnung von Änderungen der freien Energie der Bindung zum Einsatz. Die Simulationen erlauben die Analyse der auftretenden molekularen Kräfte und Energiebeiträge zur Bindung. Die Arbeit erfordert Interesse an statistischer Mechanik und der Verwendung von Simulationsmethoden am Computer.

Nanoconstrictions in ferromagnet/heavy metal bi-layers can be used to generate auto-oscillations of the dynamic magnetization via the dc spin Hall effect. We use time resolved magneto-optic Kerr microscopy with 250 nm spatial and sub-picosecond temporal resolution to study the excitation of localized auto-oscillations. Here, we would like to study coupling of localized dynamic modes to propagating modes in the ferromagnetic leads.

In nature, quarks and gluons cannot exist as free particles and are always confined into hadrons. Unfortunately, the equations of the strong interaction that governs the behavior of quarks and gluons cannot be directly solved at energy scales where hadrons form. Hence theoretical predictions of hadron properties such as their masses and decay modes are very difficult. This is in particular true for hadrons that are made of the three lightest quarks: "up", "down" and "strange". Also on the experimental side much confusion exists on what concerns masses, decay widths, and the assignment of quantum numbers of some observed hadrons, let alone the interpretation of their internal structure.

Our group participates in the COMPASS experiment at CERN, where we study the production of mesons (hadrons with integer spin) in the scattering of a 190 GeV pion beam off a stationary proton target. The produced highly excited mesons have extremely short life times of the order of 10^-24 seconds and can hence be measured only via their decay products. Our group employs and develops mathematically involved statistical analysis tools in order to identify the produced mesons with high sensitivity and to measure their properties with high precision. We have recently found a new meson with surprising properties and also did groundbreaking work on precision measurements of the properties of the pion. This science addresses one of the last open questions of the Standard Model of particle physics, which is the understanding of the strong force at large distances and low energies.

We offer thesis topics, which cover a wide range of subjects in strong-interaction physics, statistics and/or computer science. The thesis work can start at different levels within the analysis chain: from the selection of a reaction process itself up to the final fitting process leading to scientific publications. The topic can be chosen according to personal preference and interest.

Experience in computer programming is helpful, but not required.

Low energy quantum electrodynamics is the most successful physical
theory owing to the availability of accurate theoretical predictions and
extremely precise experimental measurements. Nonetheless, certain observables,
such as electron anomalous magnetic moment or the proton radius,
disclose some tension between the theory and the experiment. Therefore, both the
theory and the experiments should be further scrutinized to ensure
consistent and correct determination of fundamental constants.

In this project, the student will explore the problem of the determination of
fundamental constants in low energy experiments. Using perturbation
theory in quantum mechanics and solving numerically the Schroedinger equation
they will determine how finite charge distribution of the proton
changes the spectrum of the hydrogen atom, including the simplest possible
radiative corrections.  No prior knowledge of quantum electrodynamics is
required.

The precision optical calibration module (POCAM) has been developed for IceCube in order to improve the optical qualification of the deep ice at the South Pole. In the master / bachelor thesis, the new version of POCAM will be developed to be eventually deployed in the Mediterranea and in few years from now also in IceCube.

Small-angle neutron scattering (SANS) is a powerful technique to study correlations of condensed matter samples in the range of 20–2000 Å. As an extension of a standard SANS setup, TISANE (Time Involved Small Angle Neutron Scattering) is a new neutron scattering technique for time resolved kinetic neutron scattering. TISANE is able to resolve dynamic processes up to microsecond time-scales. The setup is based on two counter-rotating chopper disks installed at a standard small angle neutron scattering beamline.
Such a TISANE setup has recently been installed at the SANS-1 beamline at MLZ, jointly operated by TUM and Helmholtz Zentrum Geesthacht. An AC-field setup allows to apply AC fields up to 10 kHz and static fields to the sample, providing an ideal tool for the investigation of the dynamical properties of ferrofluid samples. A ferrofluid is a colloidal liquid made of nanoscale ferromagnetic particles in a carrier fluid. Ferrofluids are used for various applications like damping, speakers, liquid sealings but also in cancer therapy.
The task of this Bachelors thesis is the characterization of ferrofluid samples on a time-scale up to 10 kHz by means of time-resolved small angle neutron scattering. It includes the preparation of the samples, their characterization by means of measurements of susceptibility and magnetization, the neutron experiment and the subsequent data analysis. A solid background in solid state physics, in particular magnetism, but also mechanical skills are required. The work will be performed together with the SANS-1 team @ MLZ and offers the unique possibility to get hands on experience at an internationally leading large scale neutron facility like the MLZ.

Contact: Dr. Sebastian Mühlbauer, sebastian.muehlbauer@frm2.tum.de, 089 289 10784

Disorder has a drastic influence on transport properties. In the presence of a random potential, a system of electrons can become insulating; a phenomenon known as many-body localization (MBL) that has been envisioned by the Nobel laureate Phil Anderson. However, even beyond the vanishing transport such systems have very intriguing properties. For example, many-body localization describes an exotic state of matter, in which fundamental concepts of statistical mechanics break down. In this project we will explore these exciting aspects of many-body localization.