1,721,117 research outputs found
Performance of an X-ray spectroscopic system based on a double-gate double-feedback charge preamplifier
No full textDouble particle resolution in semiconductor drift detectors
No full textThe optimum signal processing of two close pulses produced by ionization of two close fast particles in a semiconductor drift detector is presented. The optimum is relative to the determination of charges produced by each particle and the average drift times for the released charges to reach the anode. The resolution of the charge and the drift time measurements in the presence of additive and nonadditive noises have been theoretically studied as functions of the distance between two fast ionizing particles and the amount of ionization produced by individual particles. Is it shown that the precision of the position determination of the individual particles remains good enough also in the case of a significant overlap of the two pulse
Low noise charge sensitive preamplifier dc stabilized without a physical resistor
No full textThe invention is a novel charge sensitive preamplifier (SCP) which has no resistor in parallel with the feedback capacitor. No resetting circuit is required to discharge the feedback capacitor. The DC stabilization of the preamplifier is obtained by means of a second feedback loop between the preamplifier output and the common base transistor of the input cascode. The input transistor of the preamplifier is a JFET with the gate-source junction forward biased. The detector leakage current flows into this junction. In particular, this invention, in addition to eliminating the feedback resistor, eliminates the need for external devices between the detector and the preamplifier, and it eliminates the need for external circuitry to sense the output voltage and reset the CSP. Furthermore, the noise level of the novel CSP is very low, comparable with the performance achievable with other more complex solutions
"Dynamics of electron in drift detectors".
No full textAnd 4th European Symposium on Semiconductor Detectors, Munich, West Germany, March 3-5, 198
CMOS Preamplifier with High Linearity and Ultra Low Noise for X-Ray Spectroscopy
No full textWe report here an ultra low noise charge sensitive monolithic CMOS amplifier (CSA) suitable for small anode capacitance (200 fF), low leakage current solid state detectors. The CSA is continuously sensitive, the charge from the input node being drained by a feedback transistor Mf biased as a resistor with effective values in the G/spl Omega/ range. This very high value was achieved by a novel scheme which tracks threshold variations, and power supply and temperature fluctuations. A good linearity of the CSA conversion gain is achieved (<0.1% up to 1.8 fC input charge) by inserting a voltage divider between the output of the CSA and the source of Mf. The equivalent noise charge (ENC) of the CSA is equal to the theoretical lower limit imposed by the flicker noise. The circuit has been fabricated in two different CMOS technologies. With no detector connected, we measure a room-temperature ENC of 9 e/sup -/ rms at 12 /spl mu/sec shaping time. When coupled to a cooled detector a FWHM of 111 eV is obtained at 2.4 /spl mu/sec shaping, corresponding to an ENC of 13 e/sup -/ rms. This is the best reported energy resolution ever obtained with a CMOS preamplifie
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