Jörg R. Hörandel Homepage Joerg R. Hoerandel
Development of transition radiation detectors for future space experiments

Diploma thesis Stefan Plewnia
Transition radiation detectors are suitable for direct measurements of the energy spectra of individual elements in cosmic rays up to energies of 1015 eV. They combine the advantages of good energy resolution and a large detection area with a relative small weight. Transition radiation detectors have been used successfully in the cosmic ray nuclei detector (flown on the Spaceshuttle in 1985) and the TRACER experiment. A transition radiation detector is part of the planned experiment ACCESS (Advanced Cosmic-ray Composition Experiment for the Space Station) on the International Space Station ISS.
Prototypes for a transition radiation detector have been tested at CERN in August 2001. The studies have been conducted by the University of Chicago and the University of Karlsruhe.
The test set-up has been positioned in a secondary beam of the SPS in the North Area (H2 beam line).
The set-up consists of four multiwire proportional chambers, filled with a xenon methane mixture. The first chamber measures the specific ionization. The chambers two to four are arranged behind the radiator materials and detect the sum of the energy deposit due to specific ionization and transition radiation. On the bottom, the preamplifier electronics is visible, it has been used previously on the cosmic ray nuclei detector of the University of Chicago.
Set-up of the teststand in the beamline. Top right, the beam pipe with multiwire proportional chambers to monitor the beam position and the trigger counters. Bottom left, the transition radiation test set-up.
View of the control room of the H2 beam line. The rack with the data acquisition system and the data taking computer for the transition radiation detector are on the right.
The data acquisition system, including trigger electronics and high voltage supplies for the multi wire proportional chambers and the photomultipliers is located in several VME and NIM crates. The read-out is controlled by a WIENER PCI VME Interface. The multi wire proportional chambers are read out via a SIS 3300 ADC system, which has been adapted by Struck for this application. The signals of the photomultiplier tubes are digitized by Le Croy 1182 ADCs.

Transition radiation detectors for energy measurements at high Lorentz factors
Nuclear Instrumenths and Methods


Jörg R. Hörandel