Room-temperature spectroscopic performance of a very-large area silicon drift detector

Silicon drift detectors (SDD) of small dimensions (up to 1 cm2) have been successfully employed in X-ray spectroscopy due to their small anode geometry, which allows to minimize the electronic noise due to the readout device. Many applications, however, require large sensitive areas to be covered (e.g. X-ray astronomy), so that these detectors are effectively impractical. We present the spectroscopic performance of a 53 cm2 sensitive area, multi-anode SDD, measured at room temperature using an eight-channel readout setup. The measurements, taken using 55Fe and 241Am sources, and X-ray tubes generating energies down to 2 keV, show energy resolutions in the range 290-570 eV FWHM, at 20 °C, depending on the number of anodes collecting the signal. Further developments we are carrying out could improve the detector characteristics and allow to approach the performance of small area SDDs.