Patent ID: 6054705
Filing Date: 2000-04-25
Classification: G01N

Abstract:
An apparatus for detecting and amplifying impulses of energy absorbed from incident nuclear-charged particles, X-ray photons, or gamma-ray photons, the apparatus comprising a detector-probe assembly and a signal-receiving assembly,said detector-probe assembly comprisinga high-impedance capacitive transducer for converting impulses of energy absorbed from charged-particles, X-ray photons, or gammaray photons incident on the transducer into corresponding impulses of electronic current,a non-inverting first voltage-amplifying stage having a signal input, a signal output, and a signal common, or ground-reference point, wherein the voltage gain of the first voltage-amplifying stage, referred to signal common, is essentially unity,an integrating capacitor comprising a parallel combination of components, including wiring capacitance and the equivalent input capacitance of said first voltage-amplifying stage,said integrating capacitor connected between the input of said first voltage amplifying stage and signal common,said integrating capacitor connected to a discharge means for removing accumulated charge from said integrating capacitor,said high-impedance capacitive transducer being ac-coupled between output and input of said first voltage-amplifying stage,a transconductance amplifier stage having a voltage input and a current output, where said voltage input is connected to the signal-output of the first voltage-amplifying stage, and said current output is connected to the input stage of the signal-receiving assembly through a shielded cable,the input stage of the signal-receiving assembly comprising a transimpedance amplifier.