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Mihail Iliescu

Publications and source records attributed to Mihail Iliescu.

7 recordsLinked to original sources

Kaonic Copper and Fluorine Absolute Yields Measurement with a CZT-based Detection System at DA$Φ$NE

\noindent In this work, new measurements of absolute X-ray yields for several transitions in kaonic copper and, for the first time, in kaonic fluorine are reported. The data were collected by the SIDDHARTA-2 collaboration at the DA$Φ$NE collider using a novel room-temperature Cadmium Zinc Telluride (CZT) detection system. Detection efficiencies were evaluated through a dedicated Geant4 Monte Carlo simulation of the full experimental setup, enabling the extraction of absolute yields per stopped kaon. \noindent The measured yields exhibit a systematic dependence on the principal quantum number, reflecting the interplay between radiative transitions, Auger de-excitation, and strong-interaction-induced nuclear capture. In kaonic fluorine, a suppression of the 4$\to$3 transition yield relative to higher-n transitions is observed, providing evidence for the onset of strong-interaction effects already at the $n=4$ level. From this behaviour, a conservative lower limit on the corresponding strong-interaction width is derived. \noindent These results provide new quantitative constraints for cascade models of exotic atoms and extend experimental access to intermediate atomic levels where strong-interaction effects are not directly observable via level shifts and widths. They also establish CZT-based detection as a powerful and versatile approach for high-resolution X-ray spectroscopy of kaonic atoms in collider environments.

nucl-ex

CZT Detectors for kaonic atoms spectroscopy

Cadmium zinc telluride (CZT) detectors offer excellent room-temperature energy resolution, making them well suited for X- and $γ$-ray spectroscopy in challenging environments. Within the SIDDHARTA-2 program at the DA$Φ$NE collider, a new CZT-based detection system has been developed to enable precision measurements of kaonic atom transitions in the intermediate mass range. In this work, we report the results of a calibration campaign performed with the collider operating, aimed at assessing the detector performance. A dedicated setup, including an array of quasi-hemispherical CZT sensors and a $^{152}$Eu source, was used to characterize the spectral response. The reconstructed emission lines were fitted with a model accounting for Gaussian response and incomplete charge recollection tails, and the detector linearity was evaluated by comparing the measured peak positions with their nominal energies. The results demonstrate that the CZT detector exhibits excellent linearity and stable operation with the collider on, confirming its suitability for future kaonic-atom spectroscopy at DA$Φ$NE.

physics.ins-det

Extended X-ray energy characterization of SIDDHARTA-2 large-area Silicon Drift Detectors up to 50 keV

The SIDDHARTA-2 experiment at the DA$Φ$NE collider of INFN-LNF performs high precision light kaonic atoms X-ray spectroscopy to investigate the kaon-nucleon(s) strong interaction in the low-energy (O(10 keV)) regime. A large area Silicon Drift Detectors (SDDs) system has been developed to carry out these measurements. The collaboration aims to extend the measurements campaign to higher mass kaonic atoms, which exhibit transition lines at increased X-ray energies. In this context, the spectroscopic response of the SIDDHARTA-2 SDD system was investigated in terms of linearity and energy resolution up to 50 keV. An accuracy of the energy calibration procedure $ΔE/E < 10^{-3}$ was achieved.

physics.ins-det

Time-based Selection of Kaonic Atom X-ray Events with Quasi-Hemispherical CZT Detectors at the DAFNE collider

This work presents the results of a time-based event selection for searching X-ray signals from kaonic atom X-ray transition using a single quasi-hemispherical Cadmium-Zinc-Telluride (CZT) detector at the DA$Φ$NE collider. To mitigate the high background level in the measured X-ray spectrum, a dedicated event selection strategy was developed, exploiting the precise timing correlation between e+e- collisions and detector signals. This approach enabled, for the first time, the observation of two characteristic X-ray transitions from kaonic aluminum atoms using a CZT detector: for the 5-4 transition at 50~keV, 362~$\pm$~41~(stat.)~$\pm$~20~(sys.) signal events over 1698~$\pm$~197~(stat.)~$\pm$~25~(sys.) background events in 5$σ$ were observed, with a resolution of 9.2\%~FWHM; for the 4-3 transition at 106~keV, 295~$\pm$~50~(stat.)~$\pm$~20~(sys.) signal events over 2939~$\pm$~500~(stat.)~$\pm$~16~(sys.) background events in 5$σ$ were measured, with a resolution of 6.6 ~FWHM. A strong background suppression of approximately 95\% of the triggered data was achieved through this time-based selection. The demonstrated timing capability of the CZT detector proved highly effective in isolating time-correlated events within an 80 ns window, setting an important benchmark for the application of these semiconductors in timing-based X-ray spectroscopy. These results highlight the potential of CZT-based detection systems for future precision measurements in high-radiation environments, paving the way for compact, room-temperature X-ray and $γ$-ray spectrometers in fundamental physics and beyond.

physics.ins-det

First Linearity and Stability Characterization for CZT Detection System in a e$^+$e$^-$ Collider Environment

The SIDDHARTA-2 collaboration built a new cadmium-zinc-telluride (CZT, CdZnTe)-based X-ray detection system, used for the first time in the DA$Φ$NE electron-positron collider at INFN-LNF. The aim of this work is to show that these detectors present optimal long- and short-term linearity and stability to perform precise spectroscopic measurements in a collider environment. The spectra used as references for calibration are reported, and the results about the linearity and stability studies are presented. It is also discussed and showed what is the proper function to describe all the effects that alter the Gaussian shape in semiconductors, particularly evident in the CZT case. Good residuals and resolutions were obtained for all the calibrations. In a test run with the source and the collider beam on, it was demonstrated that the calibrations made with beam off are optimal also when the beam is on, and the actual systematics in a physics run were estimated. These promising results show the potentialities of this detector in the high rate environment of a particle collider, and pave the way for the use of CZT detectors in kaonic atoms researches and in accelerators, with applications for particle and nuclear physics.

physics.ins-det

Detecting Iron Oxidation States in Liquids with the VOXES Bragg Spectrometer

Determining the oxidation states of metals assumes great importance in various applications because a variation in the oxidation number can drastically influence the material properties. As an example, this becomes evident in edible liquids like wine and oil, where a change in the oxidation states of the contained metals can significantly modify both the overall quality and taste. To this end, here we present the MITIQO project, which aims to identify oxidation states of metals in edible liquids utilizing X-ray emission with Bragg spectroscopy. This is achieved using the VOXES crystal spectrometer, developed at INFN National Laboratories of Frascati (LNF), employing mosaic crystal (HAPG) in the Von Hamos configuration. This combination allow us to work with effective source sizes of up to a few millimeters and improves the typical low efficiency of Bragg spectroscopy, a crucial aspect when studying liquids with low metal concentration. Here we showcase the concept behind MITIQO, for a liquid solution containing oxidized iron. We performed several high-resolution emission spectra measurements, for the liquid and for different powdered samples containing oxidized and pure iron. By looking at the spectral features of the iron's K$β$ emission lineshape, we were able to obtain, for a liquid, a result consistent with the oxidized iron powders and successfully quantifying the effect of oxidation.

physics.app-ph

Silicon Drift Detectors spectroscopic response during the SIDDHARTA-2 Kaonic Helium run at the DAΦNE collider

A large-area Silicon Drift Detectors (SDDs) system has been developed by the SIDDHARTA2 collaboration for high precision light kaonic atoms X-ray spectroscopy at the DAΦNE collider of Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali di Frascati. The SDDs geometry and electric field configuration, combined with their read-out electronics, make these devices suitable to perform high precision light kaonic atoms spectroscopy measurements in the high background of the DAΦNE collider. This work presents the spectroscopic response of the SDDs system during the kaonic helium first exotic atoms run of SIDDHARTA-2, preliminary to the kaonic deuterium data taking campaign

physics.ins-det