High rate X-ray spectroscopy with “CUBE” preamplifier coupled with silicon drift detector

In this work, we compare the performances of our CUBE circuit with respect to the typical performances of the external JFET transistor. We will show that CUBE enables to get superior energy resolution at short shaping time. This CUBE characteristic leads to practical advantages in several applications, like the possibility to have high-rate spectroscopy still preserving enough energy resolution to identify light elements. Alternatively, the CUBE advantages become evident in application wherever a very fast analysis is required, like in XRF mapping applications or in hand-held applications. Moreover, as known, the use of short peaking times reduces the impact of the detector leakage current on the total noise. Thus, CUBE allows to operate the detectors at room temperature (or slightly cooled). This introduces practical advantages in industrial applications avoiding the need of high power cooler stages and heat sinks, vacuum inside the SDD T08-like modules and slower startup and temperature stabilization phases. Measurements using a 25 mm2 SDD show a 260 eV FWHM resolution without any cooling of the detector; the room temperature was 25°C and the peaking time set to only 100 ns during measurement. By moderate cooling, the measured resolution was instead as good as 165 eV for a SDD temperature of 0 °C (at 300 ns peaking time). More examples of such performances will be shown as well.