Development of liquid ionization chambers for radiation therapy In cooperation with the German Cancer Research Center (DKFZ) in Heidelberg ionization chambers are developed to monitor dose values applied in radiation therapy. read more

Measurement of the fluorescence yield of electrons in air The fluorescence yield of electrons in air is measured with the AIRFLY experiment. At accelerators in Argonne, USA and Frascati, Italy electrons with MeV energies are injected into different gases (nitrogen, nitrogen-oxygen mixtures, air). This yields nitrogen molecules in excited states. During their transition to the ground state fluorescence light is emitted. The intensity of this light is investigated as function of various parameters, like pressure, temperature, and humidity. read more

Calibration of a calorimeter with liquid ionization chambers at a particle beam An iron sampling calorimeter consisting of 15 layers with four liquid ionization chambers each, with a total depth of eight hadronic interaction lengths has been tested at an external beam of the CERN SPS in Summer 2003. Pions, protons, electrons, and muons have been utilized in the energy range from 15 GeV to 350 GeV.

Development of transition radiation detectors for future space experiments Transition radiation detectors are suitable for direct measurements of the energy spectra of individual elements in cosmic rays up to energies of 1015 eV. Such detectors are developed in collaboration with the University of Chicago. A test of prototype detectors has been conducted at CERN in August 2001. read more

Measurement of drift velocities of electrons in gases An apparatus has been developed to measure drift velocities of electrons in gas mixtures. Free electrons are liberated in the gas by laser ionization and the drift time is measured with a two-beam differential method. read more