X-ray response of germanium microstrip detectors with energy and position resolution

Germanium diode microstrip arrays offer position-sensitive detection of X-rays combined with energy resolution over the range 5–100 keV. As part of a programme to develop a 300 strip photon-counting detector for Compton scattering experiments at the ESRF, we describe the design of a system permitting multiple high-density connections to cryogenically cooled detectors. We report on measurements made on two germanium microstrip strip detectors with ≈200 μm pitch fabricated using different process technologies. The position resolution and spectral energy response of these detectors has been characterised using a 15 μm wide scanning beam of monochromatic synchrotron X-rays at energies 15–100 keV. The raw data is dramatically improved by reconstruction of split-charge events arising from X-rays absorbed between contact strips, and energy spectra are obtained with peak/valley ratios >2000.