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In recent years, the resistive cylindrical chamber (RCC) has been introduced as a novel gaseous detector, extending the well-established resistive plate chambers (RPCs) to the case of cylindrical electrode geometry. Preliminary experimental studies, although still limited in number and performed under experimental conditions not always fully controlled, have nevertheless highlighted several promising features of this detector configuration, motivating the need for further systematic investigations of its operation. In contrast, from the simulation perspective, detailed studies of the RCC have not been performed yet, despite the fact that the cylindrical geometry introduces new degrees of freedom – such as cylinder electrodes radii and voltage polarity – which lead to asymmetric behaviour of the avalanche development according to the polarity of the applied voltage between the electrodes. In this work we present a standalone simulation program specifically designed to model avalanche growth and signal induction in both RPC and RCC geometries. The code implements a stepwise transport model for electron multiplication, includes approximate space-charge effects, and evaluates the induced signals on an external electrode. The simulation has been validated against experimental data for planar RPCs and subsequently applied to RCC geometries with the primary goal of investigating the underlying physical features of the cylindrical detector configuration. The results show that key observables such as induced charge and efficiency are well reproduced in the planar case, and they highlight the role of the electric-field asymmetry in shaping avalanche dynamics in the cylindrical geometry. A first comparison with available RCC experimental data is also presented, providing an initial assessment of the model performance in realistic operating conditions.

In the last few years, an intense R &D activity on particle detectors for future HEP applications has been carried on with the aim of developing new techniques as well as studying the performance of already existing detectors when operated in a high rate environment. As for Resistive Plate Chamber detectors, the main challenges to face are the improvement of their detection capabilities and longevity at very high-rates, and the search for new eco-friendly gasmixtures free from greenhouse components. Results obtained in the framework of the RPC ECOGas@GIF++ Collaboration on a thin-Resistive Plate Chamber exposed at the CERN Gamma Irradiation Facility and operated with eco-friendly gas mixtures based on Tetrafluoropropene and Carbon dioxide will be discussed in this paper.

Results obtained by the RPC ECOgas@GIF++ Collaboration, using Resistive Plate Chambers operated with new, eco-friendly gas mixtures, based on tetrafluoropropene and carbon dioxide, are shown and discussed in this paper. Tests aimed to assess the performance of this kind of detectors in high-irradiation conditions, analogous to the ones foreseen for the coming years at the Large Hadron Collider experiments, were performed, and demonstrate a performance basically similar to the one obtained with the gas mixtures currently in use, based on tetrafluoroethane, which is being progressively phased out for its possible contribution to the greenhouse effect. Long term aging tests are also being carried out, with the goal to demonstrate the possibility of using these eco-friendly gas mixtures during the whole High Luminosity phase of the Large Hadron Collider.

Since 2019, a collaboration between researchers from various institutes and experiments (i.e., ATLAS, CMS, ALICE, LHCb/SHiP and the CERN EP-DT group) has been operating several RPCs with diverse electronics, gas gap thicknesses and detector layouts at the CERN Gamma Irradiation Facility (GIF++). The studies aim at assessing the performance of RPCs when filled with new eco-friendly gas mixtures in avalanche mode and in view of evaluating possible aging effects after long high background irradiation periods, for example, high-luminosity LHC phase. This challenging research is also part of a task of the European AidaInnova project. A promising eco-friendly gas identified for RPC operation is the tetrafluoruropropene (C 3 H 2 F 4 , commercially known as HFO-1234ze) that has been studied at the CERN GIF++ in combination with different percentages of CO 2 . Between the end of 2021 and 2022, several beam tests have been carried out to establish the performance of RPCs operated with such mixtures before starting the irradiation campaign for the aging study. Results of these tests for different RPCs layouts and different gas mixtures, under increasing background rates are presented here, together with the preliminary outcome of the detector aging tests.

The great success of the Standard Model has reached its maximum with the Higgs boson discovery. However, several anomalies observed in the universe when applying the gravitational theory, lead to believe that the visible matter is not the only constituent of the universe. A new matter component, called dark matter, must be introduced through an extension of the Standard Model. A simple scenario consisting in adding a new gauge symmetry U D (1) and, as a consequence, a new (massive) gauge boson, the dark photon A′. PADME is a new experiment of the Laboratori Nazionali di Frascati searching for the A′, decaying invisibly, produced in the fixed target annihilation e+e − → γA′. The technique used by the experiment to probe the dark photon hypothesis is the missing mass method. The PADME experiment took data in two runs. Some preliminary highlights from the ongoing data analysis effort are presented.

Among the theoretical models addressing the dark matter problem, the category based on a secluded sector is attracting increasing interest. The PADME experiment, at the Laboratori Nazionali di Frascati of INFN, is designed to be sensitive to the production of a low mass gauge boson A′ of a new U(1) symmetry holding for dark sector particles and weakly coupled to the Standard Model photon. The DAΦNE Beam-Test Facility at LNF will provide a high intensity, mono-energetic positron beam impinging on a low Z target. The PADME detector will measure with high precision the momentum of the photon, produced along with the A′ boson in e+e− → A′+γ annihilation in the target, thus allowing to measure the A′ mass as the missing mass in the final state. This technique, particularly useful in case of invisible decays of the A′ boson, will be exploited for the first time in a fixed target experiment. Simulation studies predict a sensitivity on the interaction strength (ϵ2 parameter) down to 10−6, in the mass region 1 MeV < MA′ < 23.7 MeV. In this work the physics potential, the experimental strategy and the status of readiness of the experiment will be reviewed.

Since 2019 a collaboration between researchers from various institutes and experiments (i.e. ATLAS, CMS, ALICE, LHCb/SHiP and the CERN EP-DT group), has been operating several RPCs with diverse electronics, gas gap thicknesses and detector layouts at the CERN Gamma Irradiation Facility (GIF++). The studies aim at assessing the performance of RPCs when filled with new eco-friendly gas mixtures in avalanche mode and in view of evaluating possible ageing effects after long high background irradiation periods, e.g. High-Luminosity LHC phase. This challenging research is also part of a task of the European AidaInnova project. A promising eco-friendly gas identified for RPC operation is the tetrafluoruropropene (C\\(_{3}\\)H\\(_{2}\\)F\\(_{4}\\), commercially known as HFO-1234ze) that has been studied at the CERN GIF++ in combination with different percentages of CO\\(_2\\). Between the end of 2021 and 2022 several beam tests have been carried out to establish the performance of RPCs operated with such mixtures before starting the irradiation campaign for the ageing study. Results of these tests for different RPCs layouts and different gas mixtures, under increasing background rates are presented here, together with the preliminary outcome of the detector ageing tests.

In recent years, the Resistive Cylindrical Chamber (RCC) has been introduced as a novel gaseous detector, extending the well-established Resistive Plate Chambers (RPCs) to the case of cylindrical electrode geometry. Preliminary experimental studies have highlighted several promis- ing features of this configuration, motivating the need for further systematic investigations of its operation. In contrast, from the simulation perspective, detailed studies of the RCC have not been performed yet, despite the fact that the cylindrical geometry introduces new degrees of freedom- such as cylinder electrodes radii and voltage polarity- which lead to asymmetric behaviour of the avalanche development according to the polarity of the applied voltage between the electrodes. In this work we present a standalone simulation program specifically designed to model avalanche growth and signal induction in both RPC and RCC geometries. The code implements a stepwise transport model for electron multiplication, includes approximate space-charge effects, and evalu- ates the induced signals on an external electrode. The simulation has been validated against experimental data for planar RPCs and subsequently applied to RCC geometries. The results demonstrate that key observables such as induced charge and efficiency for the planar geometry are well reproduced and highlights the role of electric-field asymmetry in the cylindrical configuration. These findings provide quantitative insights into the impact of detector geometry on avalanche dynamics.

ALICE (A Large Ion Collider Experiment) studies the Quark-Gluon Plasma (QGP): a deconfined state of matter obtained in ultra-relativistic heavy-ion collisions. One of the probes for QGP study are quarkonia and open heavy flavour, of which ALICE exploits the muonic decay. A set of Resistive Plate Chambers (RPCs), placed in the forward rapidity region of the ALICE detector, is used for muon identification purposes. The correct operation of these detectors is ensured by the choice of the proper gas mixture. Currently they are operated with a mixture of C\\(_{2}\\)H\\(_{2}\\)F\\(_{4}\\), i-C\\(_{4}\\)H\\(_{10}\\) and SF\\(_{6}\\) but, starting from 2017, new EU regulations have enforced a progressive phase-out of C\\(_{2}\\)H\\(_{2}\\)F\\(_{4}\\) because of its large Global Warming Potential (GWP), making it difficult and costly to purchase. CERN asked LHC experiments to reduce greenhouse gases emissions, to which RPC operation contributes significantly. A possible candidate for C\\(_{2}\\)H\\(_{2}\\)F\\(_{4}\\) replacement is the C\\(_{3}\\)H\\(_{2}\\)F\\(_{4}\\) (diluted with other gases, such as CO\\(_{2}\\)), which has been extensively tested using cosmic rays. Promising gas mixtures have been devised; the next crucial steps are the detailed in-beam characterization of such mixtures as well as the study of their performance under increasing irradiation levels. This contribution will describe the methodology and results of beam tests carried out at the CERN GIF++ (equipped with a high activity \\(^{137}\\)Cs source and muon beam) with an ALICE-like RPC prototype, operated with several mixtures with varying proportions of CO\\(_{2}\\), C\\(_{3}\\)H\\(_{2}\\)F\\(_{4}\\), i-C\\(_{4}\\)H\\(_{10}\\) and SF\\(_{6}\\) . Absorbed currents, efficiencies, prompt charges, cluster sizes, time resolutions and rate capabilities will be presented, both from digitized (for detailed shape and charge analysis) and discriminated (using the same front-end electronics as employed in ALICE) signals.

Resistive Plate Chambers (RPCs) are gaseous detectors widely used in high energy physics experiments, operating with a gas mixture primarily containing Tetrafluoroethane (C\\(_{2}\\)H\\(_{2}\\)F\\(_{4}\\)), commonly known as R-134a, which has a global warming potential (GWP) of 1430. To comply with European regulations and explore environmentally friendly alternatives, the RPC EcoGas@GIF++ collaboration, involving ALICE, ATLAS, CMS, LHCb/SHiP, and EP-DT communities, has undertaken intensive R\\&D efforts to explore new gas mixtures for RPC technology. A leading alternative under investigation is HFO1234ze, boasting a low GWP of 6 and demonstrating reasonable performance compared to R-134a. Over the past few years, RPC detectors with slightly different characteristics and electronics have been studied using HFO and CO\\(_{2}\\)-based gas mixtures at the CERN Gamma Irradiation Facility. An aging test campaign was launched in August 2022, and during the latest test beam in July 2023, all detector systems underwent evaluation. This contribution will report the results of the aging studies and the performance evaluations of the detectors with and without irradiation.