FLC - Forschung mit Lepton Collidern

Thesis Offers

Thesis Possibilities

Our work includes a wide range of topics. Most of our projects are directly connected or closely related to international collaborations (e.g. the european AIDA project or the international LCTPC collaboration).
Possible thesis offers range from hardware development (building and testing prototypes) to software development and analysis of data taken with our various setups. Several examples of thesis topics, of which some can combined in one thesis, can be found below and are categorized into Hardware Development and Software & Analysis.

There is also the possibility to get a taste of the work in our group by joining us for a limited time (i.e. one or two weeks).

If you are interested, contact Ties Behnke or Ralf Diener.

Hardware Topics

Common Data Acquisition and Event Building for a TPC Prototype Setup (Master)

A large prototype of a Time Projection Chamber has been setup in conjunction with an infrastructure for data taking in a test beam environment. Several independent detector types are included in this setup and a common data acquisition might be needed to have unobstructed data taking. For further data processing it is also necessary to bring the data, acquired with different detectors together in terms of event building.

Large Prototype GridGEM Module

At DESY, a Large Prototype TPC is installed at the test beam area. For this prototype, a read-out module is being developed in our group. This module uses GEMs for gas amplification, which are mounted on a ceramic grid.
Several topics –which can be combined– for Bachelor, Master and PhD students are possible working on this read-out module. Some examples are listed in the following:

  • Improvement of the mechanical design.
  • Examine sources of field distortions and develop techniques to minimize them.
  • Optimization of the high voltage distribution.
  • Optimization of the GEM mounting structures.
  • Studies of the amplification homogeneity.
  • Analysis of data taken with the module.

Studies of GEM properties (Master)

In our group, a novel mounting technique for GEM foils is studied, in which the foils are glued on a thin ceramic grid instead of stretching them in a frame. One of the advantages of such a structure is that the GEM foils should have a higher flateness. In this thesis, the flatness of several large GEMs mounted on a grid will be measured –in horizontal and vertical position– as well as the amplification homogeneity. This includes a comparison to older measurements of framed and grid mounted GEMs of a smaller size.

Measurements with a TPC Prototype (Bachelor)

In this work, a setup with the medium sized MediTPC prototype will be recommissioned including data read-out and a trigger setup for cosmic muons. Using this setup, data measurements will be taken and analysed with an existing software framework. The results are input to an ongoing resolution study.

Silicon Strip Detector Setup (Master)

For the measurements taken with a Large Prototype TPC at the test beam, an envelope with a high precision silicon detector for reference measurements is foreseen to complete the setup. For this, a silicon strip detector is being designed. The work would include commissioning of the setup and first measurements.

Software Topics

Common note to all software related topics:
The following topics can be worked on individually or several of them –or a software topic with a hardware topic– could be combined in a thesis, depending on the type of the thesis (Bachelor, Master, PhD) and the progress.
The main programming language is C++, the operating system is Linux. Programming skills are welcome, but not a requisite except for the "Detailed TPC Simulation" topic.

Analysis of Large Prototype Data

DESY is hosting a complete TPC setup including a superconducting magnet at test beam area T24, which already has seen several periods of data taking with several read-out modules using different technologies. Detailed data analysis for data from some measurement periods and especially the comparison of the different results is still outstanding. Main topics are identification of shortcomings of the current reconstruction chain and its completion to be able to make comparisons. The goal of the analysis are studies of the space and momentum resolution and possibly a comparison of data from the different periods of data taking.

Hit Reconstruction techniques

Hit reconstruction, the determination of space points from measurements, is one of the key parts in track reconstruction in general. Concerning the hit reconstruction in TPCs several methods are possible. Studies with small protoypes have shown conflicting interests between algorithmic complexity and accurate definition. The central topic of a thesis would be the development of a hit reconstruction method in MarlinTPC and a comparison of complexity and performance against the current standard.

Track Fitting

The MarlinTPC software package is concerned with the provision of a reconstruction chain up to a common hit level, regardless of the underlying measurement technique. While there are basic track finding and fitting tools available, this is a goal for an external software package. Such a library is currently in development in our group, concentrating on the track finding part. The central goal of this topic is the integration of a new track model and the implementation of a fitting procedure in C++.

Detailed TPC Simulation

A common software framework called MarlinTPC exists for reconstruction and simulation of TPC data, covering both smaller prototypes and the Large Prototype TPC. There are several means of simulation available, ranging from a very rough approximation of signal generation to a very detailed description of the involved steps. The detailed simulation shows several deficiencies in terms of accuracy and modularity. The completion of a fully working and maintainable simulation is the goal of this topic.