X-ray, γ-ray and neutron detector development for future space instrumentation

• An overview of the material developments currently being pursued by ESA for use as X-ray, gamma-ray and neutron detection is given.
• The findings with respect to both Te inclusions and polarisation in compound semiconductors are described.
• The development of low noise, high resolution scintillators for gamma-ray spectroscopy is described.
• The development of a solid state neutron detector is described.

An overview of the material developments currently being pursued by the European Space Agency (ESA) with respect to X-ray, γ-ray and neutron detection media is given. The benefits underlying the selection of specific materials are discussed. In the X-ray regime the basic microphysics behind degraded spectral performance caused by the polarization effect and Te inclusions, have been investigated. We have found that both effects degrade the spectra by producing a localised distortion of the electric field. The underlying cause for the distortion does however differ. For the γ-ray regime, a low-noise equivalent scintillator to LaBr3 has been developed in the form of CeBr3. Three inch crystals with a FWHM energy resolution of 4.4% at 662 keV have successfully been produced. For neutron detection, a boron compound based solid state neutron detector has been developed that is sensitive to neutrons, alpha particles and 60 keV X-rays. The measured detection efficiency in detection for thermal neutrons was found to be in the order of a few per cent.