On the development of compound semi-conductor thallium bromide detectors for astrophysics
Publication date: 01 February 2001
Authors: Owens, A., et al.
Journal: Nuclear Instruments and Methods in Physics Research Section A: Accelerators,Spectrometers,Detectors and Associated Equipment
We discuss the detector requirements for future X-ray astrophysics missions and present preliminary results from our compound semiconductor program designed to produce X-ray detectors with high spatial and spectral resolution across the energy range 1 keV to 200 keV. Several prototype detectors have been fabricated from monocrystalline TlBr and tested at hard X-ray wavelengths in our laboratories and at the ESRF synchrotron research facility. Energy resolutions of 1.6 keV (fwhm) at 5.9 keV and 2.6 keV (fwhm) at 26 keV have been achieved, although we find that performance is highly variable due to polarisation effects. The resolution function is dominated by high leakage current at all energies. From pulse height measurements of Am241 as a function of detector bias, we derive the electron mobility-lifetime product at -2 °C to be (2.9±0.2) x 10-4 cm² V-1. This is about an order of magnitude higher than previously reported values.Link to publication