Originally designed as position-sensitive detectors for particle
tracking, silicon drift detectors (SDDs) are now used for high-count rate
X-ray spectroscopy, operating close to room temperature. Their
low-capacitance read-node concept places them among the fastest
high-resolution detector systems. They have been used in a new spectrum of
experiments in the wide field of X-ray spectroscopy: fluorescent analysis,
diffrac-tometry, materials analysis, and synchrotron experiments such as
X-ray holography and element imaging in scanning electron microscopes. The
fact that the detector system can be used at room temperature with good
spectroscopic performance and at −10°C with excellent energy
resolution, avoiding liquid nitrogen for cooling and high-quality vacuum,
guarantees a large variety of new applications, independent of the
laboratory environment. A brief description of the device principles is
followed by basics on low noise amplification. The performance results of
a complete detector system are presented as well as some dedicated
applications already realized, including use in a surface mapping
instrument and use of a “mini-spectrometer” for the analysis
of works of art. Fully depleted pn-charge-coupled devices (pn-CCDs) have
been fabricated for the European X-ray Multi-Mirror mission (XMM) and the
German X-ray satellite ABRIXAS, enabling high-speed, low-noise,
position-resolving X-ray spectroscopy. The detector was designed and
fabricated with a homogeneously sensitive area of 36 cm2. At
−70°C it has a noise of 4 e- rms, with a readout time of the total
focal plane array of 4 msec. The maximum count rate for single photon
counting was 105 cps under flat field conditions. In the
integration mode, more than 109 cps can be detected at 6 keV.
Its position resolution is on the order of 100 μm. The quantum
efficiency is higher than 90%, ranging from carbon K X-rays (277
eV) up to 10 keV.
A high rate, low noise, X-ray silicon strip detector system