Hold 1

Using numerical solver of single particle motions to probe plasma behavior
Asger Friis, s203886, Mikael Kim Tvermark Jensen, s213712, Nicolai Lomstein Jensen, s233622

Vejleder: Stefan Kragh Nielsen, DTU Fysik

Resume:
Magnetfelter bruges til at indeslutte plasma. Plasma bruges her til at skabe fusion. Fusion er en teknologi, der kan være en stabil energikilde i fremtiden. Således er det vigtigt at forstå, hvordan plasmaets partikler opfører sig i elektromagnetiske felter. Tidligere simuleringer udført af DTU Plasma Physics and Fusion Energy (PPFE) har vist visse resonansfænomener. Vi vil programmere en simulation af ladede partiklers opførsel, og sammenligne dette med kendte teoretiske resultater og med de tidligere simulerede fænomener. Yderligere vil vi, om muligt, sammenligne vores resultater fra simulationen med eksperimentelle resultater, med henblik på at få en bedre forståelse af virkelige fænomener.

Hold 1

Optical Measurements of Young's Modulus in Silicon Beams at the Nanoscale

Silje Kløverpris Munch, Adam Jabiri, Laura Lund Pontoppidan

Vejleder: Thor August Schimmell Weis, Søren Stobbe

Resume:

Microelectromechanical systems (MEMS) encompasses many different useful technologies, such as accelerometers, magnetometers, and pressure sensors. Expanding the MEMS technology to anoscale creates so-called nanoelectromechanical systems (NEMS). NEMS open up new and exciting possibilities since they exhibit different mechanical properties as well as having a greater surface area per volume compared to MEMS. In this project we will be working with comb drives, which is a type of NEMS, that is useful in the field of silicon photonics. To effectively apply NEMS, a deeper understanding of these mechanical properties is needed, specifically Young’s modulus. Experiments have  shown that the material stiffness of silicon beams in NEMS decreases when scaled down to the nanoscale,  contrary to the expectation that it should remain constant. However, these experiments are conflicting in explaining this phenomenon. The plan is to measure Young’s modulus of nanoscale silicon beams used in comb drive actuators in two ways: through optical  measurements and the use of SEM images. Ideally, the optical setup will provide higher measurement sensitivity and accuracy. The project aims to contribute to this important discussion by determining to what degree springs in comb drives become softer at the nanoscale, if at all, and comparing the results from the two measuring methods.

 

Hold 2

Quantum fiber

Oskar Hald Pedersen, Lærke Juul Johansen

Vejleder: Nika Akopian, Cristos Markos

Resume:

The internet is an essential part of modern society, as engineers we have an interest in making it better, faster and safer for users. One of the best ideas circulating right now is that of the quantum internet. The quantum internet uses quantum dots, or Qubits, as a single photon source to deliver information instead of the current use of multiple photon sources. This will both make the internet faster, since we now only need one photon to deliver information, and it will also make it much safer from potential hacking attempts. Some progress is already made in this field. Scientists already have a quantum dot be a single photon source, the issue right now is that a quantum dot will emit photon in all directions, so the chance of the photon, with all the information, going where it needs to be, is very low. That is why we want to insert the quantum dot into a nanowire waveguide in an optical fiber, in the hope that we can contain the photons and guide them to where they are supposed to go, ideally with as close to

zero loss as possible. Some has already come some of the way, Reimer et al., “Bright single-photon sources in bottom-up tailored nanowires” has made a way to create a so-called ”nanowire waveguide” or nanowire for short, which is a device with one quantum dot located roughly halfway up inside the nanowire. The nanowire will make sure that the photon, released by the quantum dot, can only go two ways along ”the vertical axis”. Afterward, they make it go only one way by covering the entrance to the optic fiber with a reflective mirror, i.e. with gold.

 

Hold 3

Turbulence measurements in NORTH using vertical probes

Aleksander Holm Eiriksson, Luc Navarro Trabolt

Vejleder: Stefan Kragh Nielsen

Resume:

Plasma physics is a very important and highly active field of research. Many physicists are working actively to make use of plasma physics, in order to create fusion energy. This is due to the great potential that it yields, in the aspects of a self-sustainable energy source, that also is completely CO2 neutral. For us to acquire said knowledge, we need to research plasma to its fullest. To advance this research field on DTU, we have been tasked with an experiment. An experiment which purpose is to further analyze the behavior of plasma inside the NORTH Tokamak. A simulation was made that showed when plasma blobs (Higher density areas inside the plasma) are thrown into the side of the wall, it distributes and stays in a certain way. To test this, the experiment is set up to analyze the plasma using a vertically mounted Langmuir probe (because the horizontally mounted probe isn't relevantly placed in order to measure what is interesting). The probe measures the potential/voltage around and inside the plasma, and by analyzing the IV-curve (All analysis is being done in Python), checking whether or not the plasma really is corresponding to the simulation. If not so, there is something that has yet to be understood and described of how plasma behaves. In this project, we are analyzing the data and providing assistance in the experiment.

 

 

Hold 4

Strategies for Increasing Neutron Rates and Energy Production in Fusor Reactors

Elisabeth Astrup Christensen, Filip Nikolaj Pisinger

Vejleder: Alexander Simon Thrysøe, Jesper Rasmussen, Søren Bang Korsholm

Resume:

In modern society, most of the world’s energy supply is covered by fossil fuels such as coal, oil, and natural gas. However, the Earth’s supply of these fossil fuels is running out, and our use of it contributes significantly to the Earth’s global warming. Fusion energy is generated by colliding light elements together under high temperatures, making the elements fuse together and creating a large amount of energy. It only takes a small amount of light elements in order to produce a large amount of energy, making fusion energy a possible contributor to an energy solution. A Fusor is an example of a device used to achieve fusion. Neutrons are released as a product during D-D fusion, making the Fusor a potential source for neutron production. Free neutrons are rare in the universe, however, they are necessary for fission reactions which is another potential contributor to the energy solution. It is therefore interesting to investigate the feasibility of utilizing the fusion neutrons for fission reactions in a fusion-fission hybrid design. In doing this, it is also of interest to investigate strategies for increasing neutron rate in Fusor reactors, in order to produce more energy in a hybrid reactor.

 

Hold 5

Quantum Photonic Devices with 2D Materials

Oliver Sebastian Ibsen, Bjørn Skat Tiedje

Vejleder: Nika Akopian

Resume:

In the field of quantum technology there is a need to make components with a high level of control when it comes to photon emission. It’s due to the need for better control over quantum components, such as transistors in quantum computers so that it becomes more precise. The solution to this comes from expansion of the Bohr-radius when performing interlayer excitation. This helps making the Coulomb interactions negligible, and eliminating the overlap of wavefunctions, as wavefunctions are probability based which isn’t ideal when high precision is needed. We therefore want to make use of the special photoluminescence(PL) characteristics of certain 2D-materials. These materials can be used to create specialised Van Der Waals(VDW) heterostructures. With the VDW heterostructures we can extend the gap between the electron and the hole, so they are the furthest apart that they can get without breaking this Bohr-radius, which is done with a method of using a spacer material inserted between 2 different materials, for example MoS2 as top layer, WS2 as the middle layer(s) and WSe2 as bottom layer. All in all, it is a fascinating subject of study to explore the manipulative use of 2D-materials to further the progress of quantum technology.

 

Hold 6

The Three A’s

Jakob Ehlern Andersen, Simon Bjerre, Oliver Sandberg Jensen

Vejleder: Radu Malureanu

Resume:

Electroncics are getting more and more compact and therefore the components are getting smaller and smaller. An important electronic component that’s hard to make smaller is the capacitor. A mix of silver, aluminium and gold can perhaps be arranged to a 3D structure that may behave as a capacitor. This project will investigate if a 2D capacitor can be made from a mixed layer of silver, aliminium and a layer of gold. The 2D capacitor can be made from migrating aluminium atoms to the border between the silver and gold layers. These metals will be deposited on a silicon wafer, with a thin layer of silica on top to avoid migration into the silicon, and will be deposited in various different configurations to see how the aluminium migrates in the alloy.

 

 

Hold 7

Characterizing shallow NV centres for spin to mechanical resonator coupling

Victor Hannibal Folting Bjerre, Johanne Birk Christensen, Victoria Søberg Thøgersen                                                                                                                                       

Vejleder: Dhiren Kara, Alexander Huck

Resume:

The relevance of quantum technology is rapidly spreading to more fields of science. This especially includes the development of quantum computing and the quantum internet. These technologies rely on quantum bits (qubits) for information storage and processing. A way to maintain a long-lived qubit is by utilising the Nitrogen Vacancy centre (NV centre) in a diamond, which combines quantum photonics and solid state physics, to maintain a Two-Level System (TLS) with a long coherence time. Placing the NV centre near the surface of the diamond allows for the state of the system to be coupled with a mechanical resonator. The mechanical resonator creates an interlink between the superconducting qubits and the NV centres. Due to the NV centres being optically active they can be used for quantum information transfer between distant superconducting qubit processors. Additionally,

exploring quantum phonon states in this context could enable the study of quantumness in relative macroscopic systems. This project aims to characterise shallow NV centres and explore their potential for spin to mechanical resonator coupling.

 

 

Hold 9

Acoustofluidics

Ahmad Amer Ghaith, Mia Due Paarup

Vejleder: Henrik Bruus

Resume:

There is a need for methods for less invasive methods of diagnostics for example to diagnose and detect early-onset cancer. That is why we are interested in studying acoustic streaming in liquid numerically. This involves creating models that enables simulations of microscale acoustofluidics. Acoustofluidic separation of cells and particles is a technology that combines acoustics and microfluidics. This is done by ultrasonic standing wave-based particle manipulation, generally done by focusing particles into a node and thereby depleting the surrounding medium of particles. This is an interesting field since this technology is used for developing ways for advanced cell handling in microenvironments for example used withing biomedical applications, and because it offers generally less invasive methods of use.

 

 

Hold 10

Optical channel height measurements using the multi-layer matrix multiplication method

Marcus Boye Jensen, Mathias Riccinardi Grand

Vejleder : Kristian Speranza Mølhave, Sofie Tidemand-Lichtenberg, Mads Søndergaard Larsen

Resume:

Insight Chips is a nanophysics company specialising in the manufacturing of millimetre-wide chips containing two microchannels along the sides connected with nanochannels across the centre. The nanochannels have been etched down to the desired diameter and can be seen from above through a silicon nitride membrane using various methods of microscopy. With this product, Insight Chips are pushing the envelope on the global Lab-on-a-chip market, and we wish to contribute to the process. In the first few weeks of working with the nanochips, we dipped our toes in the characterisation of the chip in terms of flow, electrical potential and nanochannel height to gain an idea of where in the research we could contribute. We measured the height of the nanochannels using an optical microscope and eye-balling the colour of the channel and the membrane. We thought it would be better to automate a quantitative method of these measurements to eliminate human error, and we believe that we can develop such a method in our fagprojekt. Using a spectrometer we will measure the reflection and transmission through the nanochannels of the chip. These measurements can be compared to the theoretical transmittance and reflectance as a function of channel thickness and wavelength which has been derived from the theory of one-dimensional wave propagation and normal-incident light refraction. We’ll automate this process in the form of python scripts for faster and more precise channel height assessments.

 

 

Hold 13

Optical channel height measurements using the multi-layer matrix multiplication method

August Daniel Glargaard Mikkelsen, Morten Holten Petersen, Oskar Brunn Fugmann

Vejleder: Stefan Kragh Nielsen, Mads Givskov Senstius
Resume:

Insight Chips is a nanophysics company specialising in the manufacturing of millimetre-wide chips containing two microchannels along the sides connected with nanochannels across the centre. The nanochannels have been etched down to the desired diameter and can be seen from above through a silicon nitride membrane using various methods of microscopy. With this product, Insight Chips are pushing the envelope on the global Lab-on-a-chip market, and we wish to contribute to the process. In the first few weeks of working with the nanochips, we dipped our toes in the characterisation of the chip in terms of flow, electrical potential and nanochannel height to gain an idea of where in the research we could contribute. We measured the height of the nanochannels using an optical microscope and eye-balling the colour of the channel and the membrane. We thought it would be better to automate a quantitative method of these measurements to eliminate human error, and we believe that we can develop such a method in our fagprojekt. Using a spectrometer we will measure the reflection and transmission through the nanochannels of the chip. These measurements can be compared to the theoretical transmittance and reflectance as a function of channel thickness and wavelength which has been derived from the theory of one-dimensional wave propagation and normal-incident light refraction. We’ll automate this process in the form of python scripts for faster and more precise channel height assessments.

 

Hold 17

Chemical simulation of molten salts

Viola Toftsø Nyholm, Natasha Chama Aaskoven

Vejleder: Bent Lauritzen, John Hald, Philip Jacob Ferdinand Pfahl

Resume:

It’s no secret that the need for continuous sustainable energy is more urgent than ever due to climate change which among others is a consequence of pollution from energy sources such as fossil and gas. One of the current top candidates to deliver such energy is nuclear power - independent of unstable weather conditions. Such energy is Gen IV nuclear power, which includes Molten Salt Reactors. These use fissile material dissolved in a hot and liquid salt as fuel - molten salts. This is different from previous nuclear fuels and therefore has a set of new challenges. One of these challenges is how to control the corrosiveness of the molten salts and thereby improve the endurance of the reactor. With the advance of computational chemistry this project seeks to investigate whether the thermodynamic equilibrium code Thermochimica can be used to predict the chemical behavior of molten salts. This will be done by comparing simulation results with corrosion experiments, done with NaOH.

 

 

Hold 20

Maya Soll, Mette Hillersborg Jørgensen

Vejleder: Søren Bang Korsholm, Alexander Simon Thrysøe

Resume:

In a modified version of the Linear Magnetic Mirror Device, the electrons accelerate due to an Electric field outside the magnetic enclosed area. However, the accelerated electrons create far less plasma in the enclosed area than expected. We will therefore try to obtain a better understanding of the plasma production (or lack thereof) through simulation of the velocity distribution at the end of the acceleration

tube, as the velocity distribution might be inadequate.

 

Hold 21

Production of Urea

Jonathan Holm Lindahl, Michael Schönemann-Paul

Vejleder: Alexander Bagger

Resume:

The production of synthetic fertilisers is a necessary part of continuing to feed the entire world. One of these is H2NCONH2, known as Urea. However, as it stands currently it is an immensely energy intensive and CO2 emitting process. Therefore there is a need for a more efficient usage of energy, and of the elimination of CO2 emissions in order to help mitigate the effects of climate change. By utilising electrochemical processing it could possibly achieve one or more of these objectives. We thereby wish to compare this emerging technology to the existing production methods, in order to determine if it is something we should strive to utilise in the future.

 

 

Hold 23

Energy levels in Quantum dots: A FEM-based Investigation

Muhammed Junaid Iqbal

Vejleder: Philip Trøst Kristensen

Resume:

With the help of epitaxy, a method used to grow a crystal layer on a crystalline substrate, it is possible to confine electrons within three-dimensional strained islands known as quantum dots. Quantum dots have quantum mechanical properties and a wide range of applications. These include highly efficient solar cells, Quantum Dot LED (QLED) TVs, lasers, and much more. However, to fully understand their properties, it's important to study their energy levels. Understanding the energy levels in a quantum dot is like knowing the basic moves in chess. Just as understanding the basic moves of each chess piece is the first step to developing complex strategies, scientists who know the energy levels in a quantum dot are better equipped to create more advanced experiments and applications. Conventional methods for solving the quantum mechanical equations, i.e., the Schrodinger equation, have limitations for real-world applications; they are setups that explore highly symmetric and ideal systems that don’t account for real-world configurations/interactions. To overcome these limitations, numerical finite element simulations come into play. The Finite Element Method (FEM) is a powerful numerical technique for solving partial differential equations. It achieves high accuracy by breaking down complex structures into smaller, more manageable pieces. One software that utilizes this method is COMSOL Multiphysics, which will be used for this purpose.

Hold 1

Characterization of plasma instabilities using high speed cameras

Marcus Atli Nadybal, Lærke Laura Bæk Nielsen, Alexander Johan Olsen

Vejleder: Stefan Kragh Nielsen, DTU Fysik
Resume:
Finding a stable, renewable, and clean source of energy is one of humanities most challenging and pressing issues, that simply needs a solution, if we want to continue society as it currently is. A promising source of this type of energy is fusion energy, utilizing the difference in energy levels before and after the fusion of nuclei. The fusion takes place within a reactor, that produces plasma. One of the most influential problems using plasma, is the instabilities that occur in the plasma, resulting in loss of energy output. The output/input ratio is defined as 𝑄; a measure of the reactor’s energy generating efficiency. The cause and occurrence of these instabilities will be the main focus of this project. One reason we know of is when charged particles are accelerated within the plasma. These particles will then oscillate, creating their own electromagnetic field, counteracting the applied magnetic field – which is there to ensure the containment of the plasma – causing instabilities in the plasma and thereby a diffusion and breakdown of the plasma, which results in a loss of energy output.

 

Hold 2

Characterization of a Nanoelectromechanical Spectrometer

Rasmus Kristiansen, Frederik Bylov Nielsen, William Marcus

Vejleder: Babak Vosoughi Lahijani, Søren Stobbe, DTU Electro
Resume:
Infrared spectroscopy is an important method of characterization in many industries, though most industrial scale spectrometers are highly precise they are also both bulky and expensive, which limits their wide-spread deployment in e.g. process monitoring and fieldwork. This has stimulated great interest in realising chipscale spectrometers based on scalable semiconductor production [1]. One such implementation is the Fouriertransform spectrometer (FTS) which utilises interferometry to generate an interferogram, and from this reconstruct the incoming spectrum. The particular chip-scale interferometer we will be working on has been developed and patented by our supervisors’ research group using novel bendable slot-waveguides to vary the index of refraction. The interference however is very difficult to model precisely so typically the reconstruction of spectra relies on empirical models. In this project we will extract the transfer-function and investigate the feasibility of a simple linear model for the reconstruction of a spectrum from a measured interferogram. The working mechanism will also be investigated with in-situ scanning electron microscopy (SEM). Linear models have already been applied to other FTSs with good results [2], and the goal of this project is to test whether this model is able to improve the performance of reconstruction for this design.

 

Hold 3

Produktion og brug af Zr-89

Rasmine Sofie Sund From, Amanda Liv Agerby

Vejleder: Andreas Tue Ingemann Jensen, Mikael Jensen, Kristina Søborg Pedersen, DTU Healthtech
Resume:
Positron Emission Tomography, also known as PET, is used to exoamine and diagnose tumors in cancer patients. PET uses the cancerseeking properties of radiolabeled monoclonal antibodies to create tomographical data. The data can then be used to examine the tumor, and thereby ensure the best treatment for the specific patient. The isotope 89Zr is one of the isotopes used in a PET scan. 89Zr is used for multiple reasons, some of them being: 1) Its decay properties, e.g., suitable half-life, 3.27 days. 2) The radionuclide itself is cheap to  produce and therefore ideal for use in the hospital industry. 89Zr can be created by proton bombardment of a target in a cyclotron, after which 89Zr embedded in the target is separated. Therefore it is interesting to  research whether it is possible to make a stable 89Zr target based of yttrium oxide and a thermal stabilizer. The reason yttrium oxide is attractive is that it contains less non-radioactive Zr than metallic yttrium.

 

Hold 4

Development of Pb-free Bi2Sr2Ca2Cu3O10 high temperature superconducting wires

Aleksander M. K. Christensen, Annika Dalsgaard Jensen, David Thomas Hart

Vejleder: Jean-Claude Grivel, DTU Energy
Resume:
The development of the high temperature superconductor Bi2Sr2Ca2Cu3O10 is usually made in a process where about 20% of the bismuth is replaced by lead. Despite the efficiency of this process the inclusion of lead goes against the push for more environmentally safe elements by the EU. Manufacturing of Bi2Sr2Ca2Cu3O10 superconductors without the inclusion of lead poses some difficulties. We will therefore manufacture a sample powder without the use of lead. Thereafter we will attempt multiple different doping processes to improve the reaction, in which a small amount of various other elements are included in the material (NaCl, KCl, B2O3, MgCl2typically around 0.5%), and to compare the conducting performance of wires from the different samples, including an undoped one.

 

Hold 5

Cu1 −xZnxFe2O4 Ferroelectric Film for Photocatalytic Water Splitting and Hydrogen Production

Hannah Leah Herlev Hvid, Nikoline Lykke Faurschou

Vejleder: Jean-Claude Grivel, DTU Energy
Resume:
Splitting H2O molecules into H2 and O2 molecules using sustainable energy sources is a promising process for

producing hydrogen, an interesting energy carrier for energy storage. The Cu1 −xZnxFe2O4 ferroelectric compound presents promising characteristics for this type of application, because its bandgap of 1.4-1.9 eV is in the suitable range for solar light driven water splitting. Furthermore, its pyroelectric properties may also contribute to hydrogen production upon temperature variations. The goal of this project is to develop a process to manufacture Cu1−xZnxFe2O4 films with a chemical solution deposition process and to test their water splitting ability.

 

Hold 6

Strong coupling between the light field and a mechanical oscillator

Thomas Borup Ravnborg, Christoffer Rykind Blarke

Vejleder: Alexander Huck, Daniel Allepuz Requena, DTU Fysik
Resume:
Our purpose with this project is to help in improving optical communication that is limited by the loss of photon’s quantum information. Finding a method to store the quantum information will help improving optical communication significantly and may also allow us to get better understanding of other fields such as quantum mechanics at a macro scale. This can be done by coupling a photon to a mechanical oscillator. This oscillator has to be build within a very small cavity and then the light has to be transmissioned into the cavity. Building this cavity and ensuring that the light gets into the cavity and stays there is what our project is about.

 

Hold 7

Impact of plasma current on plasma transport

Lucas Christopher Dybendal Maack, Thor Tane Schou Nielsen Deibert

Vejleder: Stefan Kragh Nielsen, DTU Fysik
Resume:
With a growing global population and higher standards of living, problems such as an increasing demand for energy and a lack of alternative energy sources are growing more relevant. Combined with global warming the need for green energy sources is becoming more prevalent. A potential solution for this problem is fusion energy, but due to a lack of research, the technology within this field is not yet ready for commercial use. One of the greater challenges with fusion power is plasma turbulence which decreases stability and efficiency. To further understand this problem we aim to calibrate an instrument called a ’Rogowski coil’ and further test it on DTU’s tokamak fusion reactor NORTH. We will calibrate the Rogowski coil with the use of a known current in an isolated system to measure the change in voltage. By extrapolating data and integrating over the output, compared to the input it is possible to correlate the magnetic flux and then determine the number of windings of the Rogowski coil. When the Rogowski coil has been calibrated we can use it to read the amount of current in the plasma and by using other diagnostics compare the amount of current to the plasma turbulence and see if running a current through the plasma minimizes loss of plasma particles.

 

Hold 8

OPTIMIZATION OF MAGNESIUM DIBORIDE SUPERCONDUCTORS

Christopher W. Toft, Malthe B. Petersen

Vejleder: Jean-Claude Grivel, DTU Energy
Resume:
With the increasing need for superconductors, the need for optimizing said conductors rises. The conventional method for producing magnesium diboride (MgB2) superconductors focuses on speed and cost-effectiveness, resulting in lesser quality. With an alternative heat treating process, we wish to achieve a superconductor with less porosity and better superconductive proberties. By testing and comparing different heat treatments, we can determine the best heat treatment process.

 

Hold 9

2nd harmonic heating in magnetically confined plasma

Johan Holmgaard Nielsen, Linnea Jensen de Leon, Maximus Marsella Rosenstrøm

Vejleder: Stefan Kragh Nielsen, Riccardo Ragona, DTU Fysik
Resume:
Fusionenergy is a worthy research subject since it helps produce cleaner renewable energy with no radioactive waste. Fusion energy can be produced in a so called tokamak, this process happens in ionized gas, or so called plasma, that is magneticlly confined and reaches up to a million degrees celsius in a tokamak. The gas is heated with harmonic microwave frequencies. In our project, we want to research if the introduction of second harmonic frequencies creates turbulence within the waves of plasma and if the usage of second harmonic frequencies instead of first hammonic frequencies, improves the energy efficiency of the tokamak. At DTU we have a reduced scale tokamak that we will use for our experiments in this project.

 

Hold 10

Mass Transport in Nanochannels

Samson Alfred Adsersen, Niels-Gabriel Gaillard

Vejleder: Kristian Speranza Mølhave, Emil Christian Stillhoff Jensen, Mads Søndergaard Larsen DTU Nanolab
Resume:
In recent years, the field of Liquid Phase Transmission Electron Microscopy - a technique used to view the behavior of nanoparticles and chemical reactions in liquid – has been on the rise, using nanofluidic chips as a window into this new world of microscopy. The electrons will interact with everything in their path, which makes it necessary to reduce the amount of surrounding bulk material i.e. working on very small scales – pictures are not great in cases of channels bigger than 200 nm. However, this means that the boundary conditions (surface potentials) have a much bigger relative influence on the observed sample. In this fagprojekt were working with a startup company (InsightChips) that produces these types of chips. Our goal is to characterize the effect of surface potentials on the movement of such samples, in the nanochannnels of their chips, using basic principles of hydrodynamics and electrokinetics; specifically electroosmosis and electrophoresis. Experimental results will be evaluated through image processing in Python, but also validated from finite element method simulations with COMSOL.

 

Hold 11

Time-resolved X-ray Solution Scattering on Aqueous Systems

Niels Pelle, Kian Latifi

Vejleder: Martin Meedom Nielsen, Verena Isabell Markmann, Morten Lunn Haubro, DTU Fysik
Resume:
In liquid phase chemistry and biology many interesting reactions and processes takes place in aqueous solutions, which includes the transportation of compounds in blood and diffusion of ions across cell membranes. In many of these processes, water either stabilizes the process or acts as an outright reaction partner. Therefore understanding these processes, requires an intimate understanding of interactions between solute and solvent. This project will focus on investigating water as a solvent and reaction partner by analyzing time-resolved X-ray solution scattering (TR-XSS) data, which provides structural information on molecular length-scales and on the time-scales of chemical reactions. We will model the direct excitation of water molecules as a function of excitation power from a laser pump pulse. Finally, we will discuss whether the model offers a full description of the excitation of water.

 

Hold 12

Stainless steel

Alba B. Larsen, Johannes Varnes, Marika B. Norby
Vejleder: Thomas Lundin Christiansen, Marcel Adrianus Johannes Somers, DTU Mechanics

Resume:
Stainless Steel is used in many different industries which require many different properties, such as low nickel concentration for implants. Therefore, many different steel alloys are created to serve  various purposes and different methods are developed to improve performance.  HTSN (High temperature solution nitriding) is one method used to implement nitrogen in high-alloy  steels, where the nitrogen is dissolved in the steel at high temperature to get higher corrosion and  deformation resistance and to minimize dichromium nitride precipitation.

 

Hold 13

Analysis of crystalline properties of III-V materials epitaxially grown on silicon

Lucas Borg Clausen, Elias Kjelstrup Bakhauge, Jakob Andreas Finne

Vejleder: Elizaveta Semenova, DTU Electro

Resume:

III/V materials are necessary for active photonic and high speed electronic applications, due to their direct bandgap structures as opposed to Si which has a indirect bandgap this means that III/V semiconductor components can absorb and emit photons with much higher efficiency than Si it would therefor be very attractive to implement III/V components into exciting Si semiconductor electronics because of Si electronics very mature fabrication process and high robustness. We therefore want to understand what kind of defects occur in these III/V materials as the amount of defects or the severity of these could be lowered or corrected for. This would help industries such as the telecom and computer industries.

Hold 14

Iron-based superconductors for ultrahigh field applications

Albert Ibsen Andersen, Julie Wolf
Vejleder: Jean-Claude Grivel, DTU Energy

Resume:

The expulsion of a magnetic field from a superconductor during its transition to the superconducting state, when it is cooled below the critical temperature is called the Meissner effect. This effect was discovered by the German physicists Walther Meissner and Robert Ochsenfeld in 1933. Since then a lot of the research into superconductors has been done to find more readily available materials and materials with a higher critical temperatures. In 2008 a family of iron based superconductor was discovered. These are the ones we will be studying. A superconductor don’t have any electrical resistance. This can be used to make a really strong electromagnet called a superconducting magnet. These magnets have been utilised in various ways including: MRI and NMR machines, mass spectrometers, and beam steering particle accelerators and some tokamaks. They have also been used in turbines to overcome restrictions imposed by high electrical current [1].

 

Hold 15

Exploring the physics of electromagnetic harvesters

Ditte Stuhr Petersen, Jeppe Elias Ekberg Jensen, Jonathan Bechsofft Mikkelsen
Vejleder: Rasmus Bjørk, DTU Energy

Resume:

An electromagnetic harvester is a small and relatively simple physical device that can harvest energy from vibrations by moving a permanent magnet relative to one or more electromagnetic coils, thereby inducing a current that can be harvested. In this project we will consider a 1D harvester, where a permanent magnet is contained within a tube, floating between to other permanent magnets that are fixed at the ends of the tube. Such vibrations harvesters are a possible way to produce energy for remote devices, that have a low power requirement and no attached power source, like many sensors connected over the internet. Compared to a battery, they could potentially be cheaper, as they don’t need to be replaced unless they break. These harvester devices are interesting to study, as the magnetic force in such a device is highly nonlinear, and exhibit hysteresis, as is the force resulting from the interaction between the magnet and the coil, so the dynamics of the device are not trivial.

Hold 17

Sound coming out of the ear - an epiphenomenon of auditory function

Philip Jensen.
Vejleder: Bastian Epp, DTU Healthtech

Resume:

Otoacoustic emissions is a phenomenon that is a relatively new discovery. It has been shown that otoacoustic emissions disappear after damage to the inner ear. Uses such as hearing test on infants

have already been implemented and is widely used to do early diagnostics of hearing impairment. It has been hypothesized that the Van der Pol oscillator can model these otoacoustic emissions and

research on this could lead to new discoveries regarding hearing impairment and/or new applications for the van der pol oscillator

Hold 18

Optical loss mechanism analysis of silicon carbide waveguides

Vilma Klemp, Malene Hamburger

Vejleder: Haiyan Ou, DTU Electro

Resume:

Leveraging the mature material growth and fabrication technology, silicon carbide (SiC) is emerging as a potential material platform for integrated nonlinear and quantum photonics because it has outstanding optical properties such as high second order and third order nonlinearity, high refractive index, and broad transmission window. Additionally, many point defects in this material are optically addressable, enabling it good candidate for single photon sources. But before all these potential applications are turned into reality, demonstration of low-loss SiC waveguides is a fundamental requirement. The loss in SiC waveguide consists of two parts. One part is from material, and the other part is from fabrication. Material loss includes absorption and scattering. Fabrication loss mainly includes scattering from surface roughness.

Hold 19

Broadband optomechanical non-linearities

Sander Jæger Linde, Magnus Vejby Nielsen
Vejleder: Søren Stobbe, Guillermo Arregui Bravo, DTU Electro

Resume:
The idea of an all-optical computer has been an unreachable dream for years, as electricity hasfundamental issues which light avoids. To reconquer the above-mentioned dream, an optical switchis needed. In order to create an optical switch it has been proposed to use optical gradient forcesto move mechanical objects. These gradient forces are best observed in waveguides. Earlier studieshave shown that the optomechanical forces act upon slot waveguides. Usually slot waveguides arefixed at the ends but by decoupling these the optical forces could allow for these to function as anoptomechanical switch. It is therefore interesting to investigate how a waveguide can be suspendedin order to take advantage of the optomechanical forces acting upon it

 

Hold 20

Removal of residue from PVA transfer of CVD grown graphene

Mikkel Ravn-Feld, Mikkel Christian Larsen
Vejleder: Abhay Shivayogimath, DTU Fysik

Resume:

The past decade has seen a rise the the applications of graphene. Today, large sheets of graphene can be synthesised using the chemical vapor deposit method (CVD), in which a single layer of graphene is deposited onto a piece of copper foil. Conventional methods of graphene transfer are costly. PVAtransfer is an alternative approach. The graphene is first transferred to a water soluble piece of PVA using a laminator to supply heat and pressure. Then, the PVA is transferred to substrate after which the substrate is covered with water, which will dissolve the PVA. However a small amount of residue is left after this process, which strongly affects the properties of the graphene. In this project we will subject the transfered graphene to a variety of treatments which can remove the leftover residue. We will use Atomic Force Microscopy (AFM), Optical Microscopy (OM) and water contact angle meassurements to determine the contamination level of the graphene before and after treatmeant. The structural quality of the graphene must also be intact, so using Raman Spectropy before and after treatment we are able to determine if our treatment may cause damage to the sheet.

Hold 21

Capping Silver

Bjarke Linnetved, Troels M. Asmussen, Omar Jennane

Vejleder: Radu Malureanu, DTU Electro

Resume:
Silver is, in theory, one of the better materials to use when it comes to optics, in particular for plasmonic applications, but it lacks chemical stability thus oxidizing very fast. We will investigate the possibility of using an aluminium oxide layer to cap and protect the silver. It should limit the oxidization of the silver layer and allow it to be used in plasmonics. The main objective is to analyze mixed silver and aluminium thin film deposition (co-sputtering), investigate if (and how quickly) the aluminium in the mixture migrates to the surface, and if the aluminium oxidizes during deposition, or after migrating to the surface. We will be testing the elemental composition of the material, its behavior and properties but will not use it in plasmonic structures.

 

Hold 22

Fabrication and charactization of silicon bottom cell devices for integration in tandem solar cells

Malli Segoli, Rasmus Torp
Vejleder: Rasmus Nielsen, Peter Vesborg, DTU Fysik

Resume:
There is a desire to become less reliant on fossil fuels due to factors such as climate change and our current energy crisis. Solar cells offer an alternative source of electrical energy; their efficiency and in turn cost are therefore paramount. Single junction solar cells are however limited to an efficiency of about 33% while two junction tandem solar cells has a peak efficiency of 45%, as two junctions with different bandgaps can utilize a wider part of the Sun’s spectral range. Silicon cells have an almost optimal bandgap for use as a bottom cell. However the p-n junction is a very sensitive part of the solar cell and the doping density of boron affects the carrier lifetime. It is therefore relevant, to investigate the effects of change in the boron doping density.

Hold 23

Nano-optoelectronic devices: Integration of electronic and Photonics

Sarah Vestergaard, Clara Wimmelmann

Vejleder: Ayman Nassar Kamel, Kresten Yvind, DTU Electro

Resume:

The exponential growth in information traffic today calls for less energy needed per bit to be sustainable, and while transistor size and logic energies keep up with Moore’s law, energy dissipation due to electrical on- and off-chip interconnects cannot. A significant amount of this energy dissipation is caused by wire charging and discharging and electronic circuits to maintain electrical signal such as amplifiers and timing recovery. In contrast, optics in waveguides does not have wire capacitance, and thus optoelectrical interconnections is a promising technology to decrease the energy needed per bit. To integrate optics into the electrical circuits on chip, a light emitter as well as detector is needed. Decreasing the size of these components entails less energy consumption, however smaller detectors are usually not efficient enough. It is therefore interesting to design energy efficient detectors using extreme dielectric confinement (EDC) in a wellknown and commercially  attractive material as Silicium.

Hold 1

Etching of hafnium disulfide for optical applications

Jens Westermann Rasmussen (s234416), Frederik Martin Felding (s225135)

Vejleder: Søren Raza, Peter Bøggild, DTU Fysik

Resume:

Hafnium disulfide (HfS2) is a novel van der Waals material with a high refractive index in the visible spectrum. This property could make HfS2 a viable candidate for fabricating nano-optics, e.g. flat metasurfaces or thin waveguides. However, to unlock this potential, an optimised etching process is needed, as current purely physical sputtering processes result in rough sample topologies. In this project, we seek to develop a dry-etch process which also uses chemical reactions between the gas and HfS2, instead of the current processes.

 

Hold 2

Automated characterization and analysis of next-generation solar cell materials

Sara Corfixsen Milthers (s224057), Selma Lien (s224069)

Vejleder: Lena Mittmann, Andrea Crovetto, DTU Nanolab

Resume:

Most of our energy today comes from fossil fuels. This is both unsustainable and damaging to the environment. Therefore, it is crucial that we convert to renewable energy sources, such as solar power. To optimize both the production of solar cell materials and the photovoltaic (PV)conversion efficiency of thin-film solar cells, phosphosulfate materials are being characterized with solar cell application in mind. Thin-film solar cells have a reduced material usage and lower cost of manufacturing compared to traditional crystalline silicon solar cells. Additionally, Phosphorusand sulfur are abundant elements on our planet, making out respectively 0.1% and 0.05% of the Earth’s crust. A way of analyzing a new material is by using Energy-dispersive X-ray spectroscopy (EDX). The characteristic X-rays are used to determine the elements that the material consists of. For the characterization of the new phosphosulfide materials, the thicknesses of the thin-films are required. The depth analysis conducted by the EDX is based on the ratio of characteristic X-rays from silicon, the wafer substrate material, and the phosphosulfide components. To validate the EDX depth analysis, cross-section images of wafers are measured directly using ImageJ. The cross-sections images are obtained with a Scanning Electron Microscope (SEM) to achieve high magnification and resolution. Creating phosphosulfide solar cells that reach a high-level of efficiency nearing the Shockley–Queisser limit could be a cost-effective solution to the energy crisis we are facing today.

 

Hold 3

Determination of the Debye length by simulation of plasma

Elias Lindegaard Andersen(s234459), Peter Nonbo Messerschmidt(s234455)

Vejleder: Anders Henry Nielsen, DTU Fysik

Resume:

A plasma is a hot collection of free electrons and ions, showing collective neutral charge over certain volumes and length scales (Debye length). This neutrality is also referred to as quasi-neutrality. Plasmas are everywhere around us, and with the urgent need for green energy like fusion power, understanding how plasmas behave is more relevant than ever. A fundamental property of plasmas is the Debye length, which can be interpreted as the length scale at which a plasma acts electrically neutral. For the plasma physics course, no. 10400, a teaching tool is needed to help students visualize how the Debyelength determines the way a plasma acts. The goal of this project is therefore to test whether simulating a plasma in a simple one-dimensional case, can predict the Debye length, and to refine the simulation such that it can be used as teaching material for the plasma physics course no. 10400.

 

Hold 4

Spatial resistance mapping of γ-Al2O3/SrTiO3 2DEGs

Stig Asbjørn Tscherning Jønsson (s234456), Emil Nymann Lund Madsen(s234426)

Vejleder: Felix Trier, Thor Hvid-Olsen, DTU Energy

Resume:

Kortlægning af resistansen i oxidholdige materialer er afgørende, da disse materialer ofte udviser komplekse og lokalt varierende elektriske egenskaber. Ved at undersøge resistansen kan man få indsigt i, hvordan struktur, sammensætning og defekter påvirker elektrisk ledningsevne. Dette er essentielt forat designe og optimere materialer til specifikke applikationer, hvor oxiders unikke egenskaber kan udnyttes. En vigtig komponent i denne forskning er 2DEG (to-dimensionel elektron gas), som dannes i grænsefladen mellem blandt andet γ − Al2O3 og SrTiO3. Denne struktur muliggør studier af elektriske egenskaber på nanoskala og kan ændre ledningsevnen med flere størrelsesordener under påvirkning af et elektrisk felt. Denne indsigt kan føre til udvikling af spintronik og spin-resistorer, som potentielt kan være mere energieffektive og kompakte end traditionelle transistorer

 

Hold 5

Numerical simulation of quantum dots with the Finite Element solver

Alex Larsen(s234030), Daniál Rasmussen(s234443)

Vejleder: Luca Vanucci, DTU Electro

Resume:

Near-future optical quantum technologies will increase the need for more sophisticated and engineered solutions using quantum light sources. Most quantum light sources are based on confining an electron-hole pair inside a semiconductor quantum dot which allows precise control of the wavelengths emitted by trapped particles upon electron-hole recombination. Therefore it is important to investigate the quantum mechanical behaviour of electrons and holes trapped in semiconductor quantum dots using appropriate simulation software.

 

Hold 6

Two phase flow and droplet generation in nanochannels

Thomas Møller Damm(s234423), Mathias Skovsbøl Andersen(s234421)

Vejleder: Kristian Speranza Mølhave, Mervan Ramadan, DTU Nanolab

Resume:

Microscale droplet generators are essential in studying interactions between different fluids at nanoscale as the high surface to volume ratio gives high reaction rates. Furthermore, lab-on-a-chip technologies as well as chemical and biological analysis use microscale droplet generators both to get a higher resolution analysis (determined by the amount of analyte per droplet) as well as saving on the amount of analyte used (determined by the volume of the droplet). Microscale droplets also allow multiple processes simultaneously with equal starting conditions, which is useful in e.g. cell mutation analyses. All of the above benefits of using microscale droplets only increase with smaller droplets, and nanoscale droplet generators capable of generating droplets consistently are therefore of interest. Previously, nanodroplets have been hard to generate, but with recent breakthroughs in nanochannel manufacturing, traditional microdroplet generation methods, using microchannels, can possibly be used. However, with a shorter scale, the ratio of surface area to volume will increase. Therefore, surface tensions will dominate the hydrodynamics to a higher degree, and investigating nanoscale droplet generating techniques is of interest.

 

Hold 7

To explore the feasibility of 3D imaging for characterising the input and output material for a CO2 mineralisation reactor

Erik Pagh Goodwin (s234461), Maria Murmann Løhndorf(s234436)

Vejleder: Susan Louise Svane Stipp, DTU Fysik

Resume:

The amount of CO2 in our atmosphere concerns society and methods to capture CO2 are being developed. A group of scientists at DTU Physics is currently researching CO2 mineralisation, where the goal is to combine waste building material with CO2, to produce a new building material. The waste materials are e.g. concrete and stone wool, which are commonly used materials in the building industry. In perspective to making a new building material with CO2, the opportunity to make a more environmentally friendly, cheap concrete additive is also being studied by the same group of scientists. This is done by characterising materials. For our project this includes diatoms, a microplanktonic algae that cover their single cells with glass structures and hold a secret for producing amorphous colloidal silica, and waste building materials concrete and stonewool before and after reaction in a CO2 trap reactor.

 

Hold 8

Characterizing an FPGA-based digitizer for fusion plasma measurements

Victor Henrik Oliver Havrehed(s234427), Tobias Peter Elholm(s234431)

Vejleder: Jesper Rasmussen, Kenneth Thranekjer Petersen, DTU Fysik

Resume:

When working with fusion energy, it is necessary to measure the properties of the plasma where the fusion processes take place. A way this is done is by injecting different wavelengths into the plasma, and receiving the scattered waves with a digitizer. For this project, the focus is microwaves, used for CTS (Collective Thompson Scattering)measurements of fusion plasmas. CTS measurements return an Intensity vs. Frequency spectrum, used to measure plasma characteristics, such as ion velocity distribution. Current digitizers have 8 bit resolution, a short sampling period, and are prone to data clogging. The digitizer in this project is 12 bit, and will analyse plasma properties in real time, with a longer sampling period. A higher resolution CTS frequency spectrum will be measured, improving on velocity distributions and temperature measurements throughout an entire plasma discharge. Before a faster FPGA (Field Programmable Gate Array), which is connected to the digitizer can be used, it needs to be calibrated in order to show accurate and precise data. The calibrated digitizer will be tested using plasmas measurements from DTU’s NORTH tokamak. The final destination of this FPGA will be the ASDEX upgrade tokamak in Germany

 

Hold 9

Fabrication of MoTe2/MoS2heterostructures and measuring PL-signals

Alexander Skjøth(s230319), Rasmus Stegelman(s234452), Victor Behrndtz (s234464)

Vejleder: Xingyu Wang and Sanshui Xiao, DTU Electro

Resume:

Due to the expanding globalised society and increasing interest in artificial intelligence, there has been an increasing demand for more energy efficient telecommunications and computer components. For this reason the field of optoelectronics has gained a lot attention for its ability to increase the speed of interconnections by replacing electronic interconnections with optical interconnections, fo rexample fibre broadband. By replacing the electronic interconnections on a motherboard with optical interconnections, the communication between the CPU, RAM and other components will be faster, since the communication is done via photons, rather than electrons. The on-chip-interconnections won’t just be faster, but also be more energy efficient, due to the increase in speed. To achieve this we need use photonic emitters such as LEDs or lasers, which can work on a micro-scale. Since silicon isn’t suited for this, due to having an indirect band gap. MoTe2/MoS2 heterostructures with direct band gaps will be used instead, which excel in the transduction of electrical signals into photonic signals

 

Hold 10

Optical characterization of nanocavities

Jens Christian Skyum(s231551), Jeppe Happy Thrane Gøhler Hoffman(s234462)

Vejleder: Jesper Mørk,  and Valdemar Christian Bille-Lauridsen, DTU Electro

Resume:

Since the beginning of the Information Age, computers and digital technology have been a feature of the modern era, increasing the standard of living and the complexity of society. The use of complex electronic devices is an essential part of daily activities, increasing the consumption of energy. Resulting in an increasing demand for faster and more energy-efficient chips. A possible solution is replacing the traditional electrical circuits with optically integrated systems. These integrated systems have both commercial and environmental potential as they outperform electrical circuits in terms of speed and generate far less heat loss. The heat loss from electrical circuits comes primarily from the ohmic resistance between interconnected components. Further motivating photonic integrated circuits. This leads to the need for increasingly small lasers. Low-dimensional nanobeam laser structure fulfills this. With buried heterostructures as the gain medium, they have practical advantages such as their compact size and easy outcoupling into waveguides. Therefore the nanobeam structures are a promising candidate for future low-cost laser cavities

 

Hold 11

Simulation of electromagnetism for Single Photon Sources

Jesper Max Rohd(s234425), Laurits Danielsen(s234068)

Vejleder: josé Ferreira Neto, and Niels Gregersen, DTU Electro

Resume:

This projects aims to investigate nanophotonic geometries for single photon sources which are discrete sources used to generate Single photons that be used as optical qubits. The single photon sources are nanophotonic geometries that contain a single quantum dot that is the source of the single photon. The nanophotonic geometries will be simulated in a program so we don’t have to manufacture them to get data. Being able to generate optical qubits can be used for the Quantum internet that exploit quantum properties for enhanced security and Quantum computers that exploit quantum properties for parallelization. The simulation portion of the project will specifically look at distributed Bragg reflectors. The quantum dot is placed in the middle of a cylindrical structure, with a certain number of reflective layers on either side of the dot. The layers have varying reflective indices, and the purpose of the structure is using these layer to enhance the photon with constructive interference.

 

Hold 12

ummerisk simulering af udbredelse af bølger i plasma

Christian Cenni Pedersen (s220971), Magnus Valdemar Juul(s203890)

Vejleder: Stefan Kragh Nielsen, DTU Fysik

Resume:

Simulation and optimization of the microwave heating system In this project we aim to model the dispersive propagation of microwaves in a plasma with an inhomogeneous plasma density and magnetic field profile. In the transition towards a greener future humanity needs to alter its means of energy production. Still today, the holy grail of green power sources is nuclear fusion. In fusion reactors the objectiveis to achieve immense pressure and temperature for nuclear fusion to occur. A way in which this is being achieved is through heating free electrons with microwaves at specific regions in the fusion chamber where the microwaves couple to the oscillatory motion of the electrons. The aim is then to hit these electrons with microwaves that match the cyclotron frequency of these electrons and accelerate them hence heating the plasma further. Since the plasma is inhomogeneous it will disperse the microwaves such that their rays are not simply traveling in straight lines. Fortunately, this can be modeled with ray tracing, where the electromagnetic field is modeled as a collection of rays, each ray with a position dependent amplitude and phase. This problem is difficult to solve analytically due to the refractive index of plasma being highly dependent on electron density and the magnetic field applied, which fluctuate locally in the plasma. In this project we aim to develop a python script that can numerically simulate the propagation of microwaves through such a medium. This will be done solving progressively more complex models of the system, where the end goal is arriving at solving a 3-d model in the cold plasma theory adding customizability to shape and entrance angle of microwaves. Work goals for this fagprojekt 1. Plotting the refractive index as a function of the magnetic field and charge density. 2. Develop a script that can simulate the propagation of waves in the 1d case under the cold plasma model, solving the raytracer equations semi analytically. 3. simulate the propagation of waves in the 1d case using automatic differentiation instead of analytic expressions for the derivatives. 3. Solving the cold plasma model for the 3d case using automatic differentiation.3.5 Using the cold ray tracer to do a parameter scan to find, e.g. the optimal entrance angle or tosee the effect of varying the geometries of the density and magnetic field profiles.

 

Hold 13

Modelling of efficiency of electricity and hydrogen generation of a fusion power plant

Lea Elling Nielsen  (s234449), Nicklas Schiøtt Rueløkke(s234446)

Vejleder: Alexander Simon Thrysøe, Søren Bang Korsholm, DTU Fysik

Resume:

In the future cleaner energy is needed. One of the ways of doing this is fusion. The energy produced with fusion need to be economically sustainable as well as environmentally sustainable. Therefore, it makes sense to examine multiple ways of employing the energy. One way of using the energy is

producing electricity in a steam turbine, this can be described with the Rankine cycle. Another way of using fusion power is producing Hydrogen with the sulfur-iodine cycle. This cycle uses the thermal energy produced in a fusion reactor. Hydrogen can be used to power cars or create fertilizers.

 

Hold 14

Piezoelectric transducers for acoustofluidic applications

Agnete Cauchi(s234442), Messaoud Sofiane Benmessaoud(s232622)

Vejleder: Henrik Bruus, DTU Fysik

Resume:

Piezoelectric devices have many applications, including lab-on-a-chip technology, where they inso-called acoustofluidic devices can be used for microparticle handling in blood-bacteria separation, focusing of red blood cells and lipids, and more. In addition, piezoelectric transducers can be used to characterize properties of materials with ultrasound spectroscopy. When optimizing such applications, numerical simulations are often used to predict the performance of the devices, and it is therefore relevant to develop, implement and use such numerical models

 

Hold 15

Plasma modeling and experimental measurementson NORTH

Mert Emren(s234429), Mohammad Ali Maanaki(s234439)

Vejleder: Alexander Simon Thrysøe, Stefan Kragh Nielsen, DTU Fysik

Resume:

We are two engineering science students, who share similar views and ambitions towards the importance of sustainable energy in the near future. Although fusion is not yet practical for large-scale energy production, great progress has been made on this topic, such as with the NORTH tokamak at DTU. The reason for this is the extreme conditions required for fusion, such as the incredibly high temperatures and electron densities. These are precisely the parameters this project aims to measure through experiments. Following the experimental data collection, we will use a simulated model of NORTH to compare and analyze any disparities between the experimental data and the numerical simulation.

 

Hold 16

Optical Simulations Of Structured Materials

Leif Pedersen(s225221), Malte Sierslev(s234463)

Vejleder: Niels Gregersen, DTU Electro

Resume:

 

Hold 17

Exploring the spatial control of the conductivity betweenSrTiO3 and γ-Al2O3 using modern printing techniques

Albert Snoer Jensen (s234453), Emil Toftedal Hansen(s234435)

Vejleder: Felix Trier, Thor Hvid-Olsen, DTU Energy

Resume:

The electronic industry is the backbone of modern society, with an ever increasing demand of efficiency. It is, however, becoming increasingly more difficult to downscale these electronic devices. Therefore studies have begun looking into the material composition of oxides and the properties they possess. More specifically, the heterostructure between the oxides SrTiO3 andγ-Al2O3 have electrical properties, such as high carrier mobility and density, as well as extreme magneto resistance, which stems from the two-dimensional electron gas created between the layers. This study will focus on the interface between these two oxides, as well as designing different Hall bars to test how different length to width ratios affect the electrical conductivity. In order to optimise the Hall bars, it would be relevant to test how thin the conducting material can be, before the channel gets too narrow to carry any electrons, thereby preventing any conductivity. Optimising the amount of Hall bars per sample, would also entail testing how far apart we can space them, before they start affecting one another electronically.

 

Hold 18

Optical characterization and testing of nanolaser cavities

Gustav Frede Green Christoffersen (s234434), Emil Møller Knudsen (s234441)

Vejleder: Jesper Mørk , Matias Marchal, DTU Electro

Resume:

The development of nanolasers for computer chips has in recent years gained significant relevance, driven by the growing demand for faster and more energy efficient solutions. As traditional components approach their physical size limits, nanolasers offer an alternative, enabling optical communication on chips rather than relying on electronic signals. This change could improve both energy efficiency and communication speed. In developing these lasers, it is especially important to examine thermal effects, as they can have a major impact on the laser’s overall efficiency.

 

Hold 19

Plasma simulation for linear devices in COMSOL

Adrian Soares (s234433), Reknagel Nielsen(s234440)

Vejleder: Alexander Simon Thrysøe, DTU Fysik

Resume:

As of now, modern societies have been more and more dependent on dwindling resources of fossile fuel. That coupled with the increasing problems coming from CO2 emissions causing global warming, have made it clear, that we are in need of alternative sustainable energy solutions. One solution could be nuclear fusion, combining atomic nuclei together to produce energy. But although this method works on paper, the obstacle of producing a higher energy output is difficult and requires a lot of resources. For that purpose, research on nuclear fusion needs to be studied further by looking into the core concept, that is producing plasma. Matter that is turned into a plasma creates an environment, where nuclear fusion is easier to achieve, because of an abundance of charged particles in any combination of ions or electrons. But as plasma has unique and complex properties, such as a high temperature, the need for magnetic confinement, a high energy density, complex diagnostics and is electrically conductive, can make working with plasma a hassle and a hazard zone, when it is not created in a controlled environment. Therefore, a lot of experimental setups have been made to study and handle plasma to accomplish the goal of a higher energy output in nuclear fusion. One of these experimental setups used, are linear devices, that has advantages when it comes to studying plasma. With its linear configuration and easier to handle magnetic confinement, while also having accessibility to measurements and not to mention modular design, being easy to scale up or modify, making them adaptable for a lot of purposes. This project will therefore focus on simulating how plasma behaves in such linear devices, to help predict and improve experimental setups, which goal is to unravel the mysteries behind plasma to create an energy solution.   

 

Hold 20

Neutron and x-ray emission in the DTU Fusor

Jonathan Wennerberg(s234418), Philip Meyer(s234451)

Vejleder: Jesper Rasmussen, DTU Fysik

Resume:

The DTU-Fusor is an experimental device for creating plasmas and producing neutrons that can be used to research various aspects of fusion. The neutrons are created in fusion reactions, and X-rays are produced by bremsstrahlung emitted from the fusion plasma. One of the uncertainties with the Fusor is whether the X-ray- and neutron emission is isotropic or not, and what the energy distribution of the electrons that create the X-ray, looks like. These main uncertainties are what we wish to help clarify. It is therefore a good idea to create a model of the neutron distribution and transport in the Fusor, which we will accomplish through measuring the physical properties of the Fusor and inputting them into OpenMC, a Monte Carlo neutronics modeling package in Python, where we are able to simulate a realistic fusor and its transportation of neutrons through the wall of the Fusor chamber, that consists of different materials. The X-ray emission models are to be created from different X-ray relevant equations that we implement in Python to create spectra and graphs. Furthermore, if the analytical models aren’t accurate enough, we will apply more advanced numerical computational software.

The climax of the project is then to carry out measurements to check if these models accurately represent the processes in the Fusor. For the neutron distribution model, the neutron detector will be placed at various locations around the Fusor, to accurately compare with the simulation results.

For the X-ray emission models, the goal is to compare the measured spectra (intensities) at different voltages (the higher the voltage, the higher the acceleration of the electrons, leading to different X-ray spectra) and with different gasses, with the aforementioned models.

 

Hold 23

lineære magnetfelter, med og uden permanente magneter

Stig Kvistgaard Jensen (s234428), Emil Kenneth Elk (s234428)

Vejleder: Søren Bang Korsholm, DTU Fysik

Resume:

One of the most important tasks of modern-day science is the search for clean, renewable energy. Wind, solar and hydro energy have each been used, but have their respective limitations. Wind and solar are somewhat unreliable without incredible battery capacity, and hydro is stunted by the simple fact that there are only so many places on Earth where you can build a dam. Enter fusion energy. Fusion promises a clean, renewable energy source, provided we can make it work reliably. In a fusion reactor, energy is released from nuclear fusion reactions in super-heated plasma, held at millions of degrees Kelvin. A major challenge in the field of fusion energy is the creation of magnetic fields that keep the plasma in place. Our goal is to test a device that emulates the way a stellarator works, using permanent magnets. We will study and compare linear representations of 3 different ways of creating and/or simulating said fields: Coil-based (stellarator),magnet-based (the new device), and the ideal field, calculated numerically. We want to do this because getting accurate simulations for a linear field will eventually allow modelling and emulation of the corresponding toroidal field.

 

Hold 24

dTof measurements with pulsed laser andSPAD/MPPC for LiDAR technology

Asger Flindt Kirkebæ (234448), Eskild Præstholm (s234424)

Vejleder: Hao Hu, DTU Electro

Resume:

LiDAR imaging is used in numerous technologies and usage is continuously growing. One of the fundamental limiting factors of the technology is the detection of returning light, for which many technologies have been used such as Electron Multiplying Charge-Coupled Device (EM-CCD), Intensified Charge-Coupled Device (I-CCD), Avalanche Photodiode (APD), Single PhotonAvalanche Diode (SPAD) and Silicon Photomultiplier (SiPM). A promising technology in this field is the SPAD which utilizes the Avalanche effect in a reverse-bias configuration to measure instances of photon hits. The distance of objects can be measured with the time difference between the outgoing light and the returning light measured with the SPAD. The SPAD and the laser is crucial for increasing the range and quality of the distance measurement.

 

Hold 25

Performance characteristics of Graphene Field Effect Transistors with Ionic Gating

Lasse Søndergaard (s234458), Magnus Biehl Nielander (s234438)

Vejleder: Peter Bøggild, Bjarke Sørensen Jessen, Robert Steen Raunsgaar, DTU Fysik

Resume:

Graphene has the potential to revolutionize a wide range of industries. The aim of this project is to utilize graphene in a field effect transistor (GFET) with electrolytic gating to achieve carrier modulation substantially higher than that with electrostatic gating. This is realized through characterization of GFET’s from the Spanish graphene provider Graphenea, determining suitable electrolytes, and describing the doping and hysteresis effects nearly always seen in such devices. All of this work provides a useful platform for research and applications in biosensing and electrochemistry.

 

Hold 26

Design and Production of Special Alloys for Laser Powder Bed Fusion

Jacob Emil Andreasen (s223660), Albert Ljungberg Sørensen (s234460)

Vejleder: Niels Skat Tiedje, DTU Construct

Resume:

Metal additive manufacturing (AM) processes like LPBF involve rapid cooling and complex heat treatment cycles, resulting in microstructures and properties distinct from those seen in conventionally manufactured materials. This project focuses on atomizing and characterizing recycled tool steel to understand its suitability as a powder feedstock for AM, with the potential to develop tailored alloys for improved performance.