arXiv subjects

Olivier Stézowski

Publications and source records attributed to Olivier Stézowski.

3 recordsLinked to original sources

arXiv2026

Neural Networks for 3D Characterisation of AGATA Crystals

Precise localisation of gamma-ray interactions is crucial for the performance of the Advanced GAmma Tracking Array (AGATA). The Pulse Shape Analysis (PSA) method used for the position estimation of gamma-ray interactions relies on a simulated signal database. The Pulse Shape Comparison Scanning (PSCS) method was used to scan AGATA crystals in order to produce an experimental database of signals. This paper presents a novel approach using Long Short-Term Memory (LSTM) neural networks to determine the 3D interaction position of gamma rays within AGATA crystals, trained on data from IPHC Strasbourg, allowing for the construction of an experimental database. A custom masked loss function is introduced to enable training with incomplete position information. The database generated by this new method outperforms the existing simulated database, and the experimental database obtained from the conventional PSCS algorithm.

physics.ins-det↗

arXiv2023

AGATA DAQ-box: a unified data acquisition system for different experimental conditions

The AGATA tracking detector array represents a significant improvement over previous Compton suppressed arrays. The construction of AGATA led to numerous technological breakthroughs in order to meet the requirements and the challenges of building a mobile detector across Europe. This paper focuses on the design and implementation of the data acquisition system responsible of the readout and control of the germanium detectors of AGATA. Our system is highly versatile, capable of instrumenting AGATA and seamlessly adapting it to various configurations with a wide range of ancillary detectors and/or spectrometers. It consists of three main components: an autonomous and independent infrastructure, a dedicated application core ensuring overall consistency, and a high--performance software package providing a fully integrated data flow management including the setting-up, the supervision and the slow control of the instrument. In this paper, we present a comprehensive analysis of the system's design and performance, particularly under high-counting rate conditions.

physics.ins-det↗

arXiv2018

Gamma-ray intensities in multi-gated spectra

The level structure of nuclei offers a large amount and variety of information to improve our knowledge of the strong interaction and of mesoscopic quantum systems. Gamma spectroscopy is a powerful tool to perform such studies: modern gamma multi-detectors present increasing performances in terms of sensitivity and efficiency, allowing to extend ever more our ability to observe and characterize abundant nuclear states. For instance, the high-spin part of level schemes often reflects intriguing nuclear shape phenomena: this behaviour is unveiled by high-fold experimental data analysed through multi-coincidence spectra, in which long deexcitation cascades become observable. Determining the intensity of newly discovered transitions is important to characterize the nuclear structure and formation mechanism of the emitting levels. However, it is not trivial to relate the apparent intensity observed in multi-gated spectra to the actual transition intensity. In this work, we introduce the basis of a formalism affiliated with graph theory: we have obtained analytic expressions from which data-analysis methods can eventually be derived to recover this link in a rigorous way.

physics.data-an↗