Silicon drift detector with integrated p-JFET for continuous discharge of collected electrons through the gate junction

The paper describes the design and the performance of a silicon drift detector with integrated front-end electronics for large area, high resolution X-ray spectroscopy. The detector features a new type of p-JFET embedded in the collecting anode and operated with the gate-to-channel junction forward biased by the detector leakage current. This unusual condition performs, at the same time, the amplification of the signal and the continuous discharge of the collected charge eliminating any additional component or system for resetting. The particular design of the transistor allows the anode region to be very compact without affecting the collection of the charge. Using a test device with an active area of 3 mm2 the detector has reached an energy resolution of 19 electrons rms at an operating temperature of 208 K.