Detector Development

A strong focus of our group is the development of silicon detectors, in particular for the CMS experiment. In a dedicated silicon lab we develop radiation hard silicon materials able to withstand the high particle fluxes at LHC and SLHC and participate in the RD50 collaboration. Sensor design was done for the ZEUS micro vertex detector and is currently studied for the upgrade of the CMS pixel detector. Large scale detector production was done for both ZEUS and CMS.
Our group is also strongly involved in characterization of Silicon-PhotoMultipliers (SiPM) and their applications to high-energy physics and medical fields. We are involved in the detector development for the future linear collider, via the CALICE collaboration, aiming to develop novel calorimeter designs for the application of particle flow techniques. As a spin-off of this activity the group is also active in the medical exploitation of SiPM to Time of Flight Positron Emission Tomography.

CMS detector upgrade projects

Our group is strongly involved in two phases of the CMS detector upgrade.

The 
phase I update is scheduled for the years 2016-2017. In this phase we are involved in the upgrade of the pixel detector. The phase II upgrade is foreseen around 2020. For this project our focus lies on the upgrade of the full CMS tracking detector.

Image source: CMS/CERN

Basic research in silicon radiation damage

Our group is a longstanding leader in radiation damage studies in silicon for high energy physics experiments and, more recently, also photon science. We study radiation induced defects in the silicon band gap and their effects on basic sensor properties like dark current, effective space charge concentration and trapping of charge carriers. This research is done in the framework of the RD50 collaboration. We make use of a suite of measurement techniques ranging from current-voltage and capacitance-voltage characterization, measurements with radioactive sources and lasers to microscopic techniques like the deep level transient spectroscopy (DLTS) and thermally stimulated current (TSC). The latter allow the spectroscopy of energy levels in the silicon band gap corresponding to specific radiation induced latice defects. Together, macroscopic and microscopic measurement techniques give us a more complete picture of radiation damage in silicon and help us identify more radiation tolerant silicon materials. (Foto: UHH/Wilken)

Particle flow calorimetry

Particle flow is a new approach to calorimetry which promises to achieve a jet energy resolution which is more than a factor of two better than traditional calorimetric approaches. It has the potential to revolutionize detector design for future lepton collider experiments. Particle flow is predicated on the ability to reconstruct the energies of the individual particles in a jet. It requires highly segmented detectors and sophisticated reconstruction techniques.

Calorimeters for medical applications

We study the application of novel semiconductor based photodetectors in Time-Of-Flight Positron Emission Tomography (PET). Specifically, our expertise is in Silicon Photomultipliers and Single-Photon Avalanche Diode (SPAD) photosensors implemented in Complementary Metal-Oxide-Semiconductor (CMOS) technology. The implementation of photosensors with photon count capabilities in silicon results in a very good timing performance, a staggering advance in miniaturization and in magnetic field resistance that would allow the implementation of the PET technique in magnetic resonance imaging.

The MADMAX Experiment

The Magnetized Disc and Mirror Axion experiment (MADMAX) is designed to detect a new particle called the Axion. Axions are extremely well motivated particles beyond the Standard Model because they can solve the strong CP-problem and serve as a Dark Matter (DM) candidate.