Analysis and mitigation of pulse-pile-up tail artifacts in warm-plasma pulse-height X-ray spectra

TL;DR

This paper develops a first-principles model for pulse pile-up artifacts in X-ray spectra from warm plasma, enabling diagnosis and mitigation of tail artifacts to improve spectral accuracy at low count rates.

Contribution

It introduces a novel two-photon pulse-pile-up model specific to trapezoidal pulses and demonstrates its use in diagnosing and mitigating spectral artifacts.

Findings

Model accurately predicts pulse pile-up tail artifacts.

Mitigation improves spectral fidelity in low count-rate measurements.

Model aligns well with experimental data.

Abstract

Pulse pile-up in pulse-height energy analyzers increases when the incident rate of pulses increases relative to the inverse of the dead time per pulse of the detection system. Changes in the observed energy distributions with incident rate and detector-electronics-formed pulse shape then occur. We focus on weak high energy tails in X-ray spectra, important for measurements on partially ionized, warm, pure-hydrogen plasma. A first-principles two-photon pulse-pile-up model is derived specific to trapezoidal-shaped pulses; quantitative agreement is found between the measurements and the model predictions. The modeling is then used to diagnose pulse-pile-up tail artifacts and mitigate them in relatively low count-rate spectra.