Speaker
Description
Charge-sensitive spectroscopic readout chains are widely used to measure single-particle energy distributions across various scientific fields. A typical analog front-end consists of a charge-sensitive preamplifier and a shaping filter, which together produce well-defined pulses for digitization and pulse height measurement. In such systems, achieving higher amplitude resolution requires increased shaping constants. At high rates, however, pulse pileup distorts spectra and cannot be effectively managed by traditional pileup rejection circuits.
This work introduces a rejection algorithm based on the deconvolution method, capable of handling severely piled-up data. By matching a finite impulse response filter to the analog front end, the timestamps of individual events are reconstructed with high accuracy, enabling an improved rejection logic. This approach allows the use of extended shaping times while maintaining pileup-free measurements, thereby enhancing spectral resolution. It does not require a secondary fast amplification channel. Filters like this are easily implemented digitally and can be realized in hardware as switched capacitor arrays. Potential applications include low-charge-yield measurements at high rates, such as those used in the microdosimetric characterization of medical ion beams as well as high-resolution alpha and gamma spectroscopy.
The method has shown promising results in tests with radioactive sources. Testing in an ion beam is scheduled.
