Crilin: CRystal calorImeter with Longitudinal InformatioN for a future Muon Collider

Being modern tracking systems very precise, jet performance in particle flow-like reconstruction algorithms is usually limited by the calorimeter performance. In particular, a high granularity is required in order to distinguish signal particles from background and to solve the substructures necessary for jet identification. Time of arrival measurements in the calorimeter could play an important role in HL-LHC, since a high number of pile-up collisions is expected, and the timing could be used to assign clusters to the corresponding interaction vertex. In a Muon Collider, the timing could be used to remove signals produced by beam-induced background, asynchronous with respect to the bunch crossing. The calorimeter energy resolution is also fundamental to measure the kinematic properties of jets: a finely segmented calorimeter design should be favored in order to solve the jet substructure. However, this contrasts with the requirement for high timing resolution even for signal events involving low energy deposits, such as in the case of high impulse muons. Our proposed design, the Crilin calorimeter, is a semi-homogeneous calorimeter based on Lead Fluoride (PbF2 ) Crystals readout by surface-mount UV-extended Silicon Photomultipliers (SiPMs). In this paper, the development of a small prototype consisting of 2 layers of 3 × 3 crystals each is reported along with the relative results

Performances of an Active Target GEM-Based TPC for the AMADEUS Experiment

In this paper, we present the R & D activity on a new GEM-based Time Projection Chamber (GEM-TPC) detector for the inner region of the AMADEUS experiment, which is aiming to perform measurements of low-energy negative kaon interactions in nuclei at the DAΦNE e+ e- collider at LNF-INFN. A novel idea of using a GEM-TPC as a low mass target and detector at the same time comes motivated by the need of studying the low energy interactions of K- with nuclei in a complete way, tracking and identifying all of the produced particles. Even more, what makes the experimental proposal revolutionary is the possibility of using different gaseous targets without any other substantial intervention on the experimental setup, making it a flexible multipurpose device. This new detection technique applied to the nuclear physics requires the use of low-radiation length materials and very pure light gases such as Hydrogen, Deuterium, Helium-3, Helium-4, etc. In order to evaluate the GEM-TPC performances, a 10 × 10 cm2 prototype with a drift gap of 15 cm has been realized. The detector was tested at the πM1 beam facility of the Paul Scherrer Institut (PSI) with low momentum pions and protons. Detection efficiency and spatial resolution, as a function of gas mixture, gas gain and ionazing particle, are reported and discussed

Purification of large volume of liquid argon for LEGEND-200

The design, construction and performance of the system capable of purifying 65m$^{3}$ of liquid argon to sub-ppm level designed for LEGEND–200 experiment is presented. The quality of the purified liquid argon is monitored in real-time during the purification process, by measuring the argon triplet state lifetime and simultaneous direct measurements of the concentrations of impurities such as water, oxygen, and nitrogen with a sensitivity of 0.1 ppm. The achieved argon triplet lifetime value measured inside the LEGEND cryostat, when filled in 70% of its capacity, was at the level of $\tau_{3}$ = 1.3 μs. If needed, the system may also be used later to purify liquid argon already filled into the LEGEND cryostat in the loop mode

Crilin: A Semi-Homogeneous Calorimeter for a Future Muon Collider

Calorimeters, as other detectors, have to face the increasing performance demands of the new energy frontier experiments. For a future Muon Collider the main challenge is given by the Beam Induced Background that may pose limitations to the physics performance. However, it is possible to reduce the BIB impact by exploiting some of its characteristics by ensuring high granularity, excellent timing, longitudinal segmentation and good energy resolution. The proposed design, the Crilin calorimeter, is an alternative semi-homogeneous ECAL barrel for the Muon Collider based on Lead Fluoride Crystals (PbF2) with a surface-mount UV-extended Silicon Photomultipliers (SiPMs) readout with an optimized design for a future Muon Collider

A novel High-Voltage System for a triple GEM detector

A novel High-Voltage System for a triple GEM detector has been designed and realized in Frascati within the LHCb muon detector framework. The system is built with seven floating power supply, with a maximum of 1200 V each, and controlled via CANbus, for voltage settings and monitoring. Several HV modules can be installed in a nano-ammeter mainframe already developed in Frascati, realizing a HV crate able to supply up to 24 triple GEM chambers with a 1 nA resolution monitoring system

Applications in beam diagnostics with triple GEM detectors

The development of different detectors based on GEM technology, mainly to be used for beam diagnostic, is described. The use of GEM foils for detector construction started in Frascati on 2002 with the R&D for LHCb Muon Chambers placed at small angle. Ever since several triple GEM chambers have been built for different applications. The results obtained in several beam tests have shown high performances: high rate capability (50 MHz/cm^2), good time resolution (4 ns), good space resolution O(200 um) source, and good aging resistance after 2C/cm^2 source of integrated charge. Recent developments on readout electronics and power supply for portable detectors are presented

Characterization of GEMINI, a 16-channels programmable readout interface for Triple-GEM detectors in 180nm CMOS

The recent advances in GEM detector development has led to the requirement of a custom readout to fully exploit the advantages of this technology. GEM detectors can be realized with various shapes, also irregular, and high number of channels. GEMINI has been specifically designed to work with Triple-GEM detectors and it integrates 16 channels to perform readout with both analog and digital signal with Time over Threshold. GEMINI also allows to set a different threshold for every channel to compensate channel inhomogeneity. This work compares simulations with lab measurements and presents results of the imaging of an X-ray source performed with GEMINI

The LEGEND-200 Liquid Argon Instrumentation: From a simple veto to a full-fledged detector

LEGEND-200 is an experiment designed to search for neutrinoless double beta decay of 76Ge by operating up to 200 kg of enriched germanium detectors in liquid argon (LAr). To achieve ultra-low backgrounds, the LAr is instrumented to detect scintillation light emitted upon interactions with ionizing radiation, thus tagging and rejecting backgrounds. The LAr scintillation light is detected with wavelength-shifting fibers coupled to silicon photomultiplier (SiPM) arrays. In this document, we demonstrate the high photoelectron resolution and low noise level of the SiPM signals. We also present the results of special calibration runs performed to determine the light yield and background suppression factors. We show the background suppression performance of the LAr instrumentation on the LEGEND-200 background spectrum before and after the LAr light coincidence cut. Finally, we present the event topology classifier which enables effective particle discrimination, allowing the identification of background types in LEGEND-200

Purification of large volume of liquid argon for LEGEND-200

The design, construction and performance of the system capable of purifying 65m$^{3}$ of liquid argon to sub-ppm level designed for LEGEND–200 experiment is presented. The quality of the purified liquid argon is monitored in real-time during the purification process, by measuring the argon triplet state lifetime and simultaneous direct measurements of the concentrations of impurities such as water, oxygen, and nitrogen with a sensitivity of 0.1 ppm. The achieved argon triplet lifetime value measured inside the LEGEND cryostat, when filled in 70% of its capacity, was at the level of $\tau_{3}$ = 1.3 μs. If needed, the system may also be used later to purify liquid argon already filled into the LEGEND cryostat in the loop mode

Dark sector studies with the PADME experiment

The Positron Annihilation to Dark Matter Experiment (PADME) uses the positron beam of the DAΦNE Beam-Test Facility, at the Laboratori Nazionali di Frascati (LNF) to search for a Dark Photon A′. The search technique studies the missing mass spectrum of singlephoton final states in e+e− → A′γ annihilation in a positron-on-thin-target experiment. This approach facilitates searches for new particles such as long lived Axion-Like-Particles, protophobic X bosons and Dark Higgs. This talk illustrated the scientific program of the experiment and its first physics results. In particular, the measurement of the cross-section of the SM process e+e− →γγ at ps=21 MeV was shown