High-time-resolution X-ray observations of compact objects provide direct access to strong-field gravity, to the equation of state of ultradense matter and to black hole masses and spins. A 10 m²-class instrument in combination with good spectral resolution is required to exploit the relevant diagnostics and answer two of the fundamental questions of the European Space Agency (ESA) Cosmic Vision Theme “Matter under extreme conditions”, namely: does matter orbiting close to the event horizon follow the predictions of general relativity? What is the equation of state of matter in neutron stars? The Large Observatory For X-ray Timing (LOFT), selected by ESA as one of the four Cosmic Vision M3 candidate missions to undergo an assessment phase, will revolutionise the study of collapsed objects in our galaxy and of the brightest supermassive black holes in active galactic nuclei. Thanks to an innovative design and the development of large-area monolithic silicon drift detectors, the Large Area Detector (LAD) on board LOFT will achieve an effective area of ~12 m² (more than an order of magnitude larger than any spaceborne predecessor) in the 2–30 keV range (up to 50 keV in expanded mode), yet still fits a conventional platform and small/medium-class launcher. With this large area and a spectral resolution of <260 eV, LOFT will yield unprecedented information on strongly curved spacetimes and matter under extreme conditions of pressure and magnetic field strength.

This work presents an analysis of silicon carbide (SiC) as semiconductor for the realization of detectors for soft X-rays (<20 keV). On the basis of experimental data on prototype SiC junctions, the performance in X-ray spectroscopy using planar diode and drift detectors in SiC have been estimated in a wide range of operating temperature (up to 150/spl deg/C). It has been derived that, due to their extremely low reverse current density (4.7 pA/cm/sup 2/ at 300 K and 17 pA/cm/sup 2/ at 340 K and at electric field of 100 kV/cm), SiC detectors can potentially reach superior performance with respect to all the other semiconductors presently employed at or above room temperature. In particular, a comparative theoretical analysis, based on experimental data on state-of-the-art silicon and SiC junctions, shows that SiC detectors with areas larger than 1 mm/sup 2/ have the potentiality to offer higher energy resolution when operating at temperature above 25/spl deg/C. An energy resolution of about 700 and 1300 eV FWHM have been estimated for 1 mm/sup 2/ and 10 mm/sup 2/ SiC pad detectors operating at 100/spl deg/C with a silicon front-end FET. The contribution of a standard silicon front-end electronics on the system performance has been analyzed. The open issues in SiC technology for X-ray detector development are highlighted.

In this paper a method for disentangling the various noise components in semiconductor radiation detector–amplifier systems is described and experimentally tested. A charge amplification scheme is adopted for the measurements. It is shown how an accurate estimate of the series and parallel white noise, 1/f series noise, and f parallel noise can be quickly obtained through a multiparameter least‐squares interpolation of the equivalent noise charge data of the system.