Development of a wide dynamic range and high-precision ammeter for beamline instrumentation at SIRIUS

Sirius beamlines require specialized electronic devices to monitor key parameters of the photon beam, such as position and flux, through the detection of extremely low-level electrical currents. Furthermore, experiments conducted in fly-scan mode usually demand fast, high-precision low-level current measurements. To address these requirements, the development of a wide dynamic range ammeter (from 1 pA to 10 mA) has been addressed, based on a logarithmic transimpedance amplifier, eliminating the need for scale switching and featuring high precision and fast response. The proposed device converts the input current into a logarithmic output voltage and offers two operation modes: the logarithmic ammeter and the logarithmic ratiometer, both of which are particularly useful in X-ray spectroscopy experiments. This paper considers an overview of the device as well as its preliminary characterization and results, including logarithmic conformity, bandwidth, and noise.