Instruments

25 pages, 7518 KB

Open AccessArticle

Machine Learning-Driven Beam Tuning Using Adaptive Region Bayesian Optimization at INFN-LNL

by Ysabella Kassandra Ong, Luca Bellan, Damiano Bortolato, Maurizio Montis, Michele Comunian, Natalia Milas, Ryoichi Miyamoto, Domenic Nicosia, Francesco Grespan, Enrico Fagotti and Andrea Pisent

Instruments 2026, 10(2), 33; https://doi.org/10.3390/instruments10020033 - 9 Jun 2026

Viewed by 218

Abstract

Machine Learning (ML) techniques are increasingly being adopted in particle accelerator operations to enable efficient control of complex systems. At INFN–LNL, we investigated both offline and real-time ML-driven approaches to enhance beam quality, reduce setup time, and improve reliability across different accelerator facilities. [...] Read more.

Machine Learning (ML) techniques are increasingly being adopted in particle accelerator operations to enable efficient control of complex systems. At INFN–LNL, we investigated both offline and real-time ML-driven approaches to enhance beam quality, reduce setup time, and improve reliability across different accelerator facilities. As part of this effort, we developed Adaptive Region Bayesian Optimization (ARBO), a custom Bayesian Optimization algorithm that dynamically expands its search domain when the predicted optimum approaches a boundary. Offline studies applied ARBO to the design optimization of the medium-energy beam transport line of the ANTHEM BNCT facility. Real-time online tests demonstrated the effectiveness of ARBO. At PIAVE–ALPI, the combined transmission improved from 44.2% to 52.6%, corresponding to an ALPI-only increase from approximately 69% to 82%, approaching the theoretical maximum of 93%. At the ESS normal-conducting linac, ARBO enabled the simultaneous tuning of more than 50 control elements while improving transmission and maintaining stable trajectory correction. These results indicate that adaptive optimization strategies can substantially improve accelerator performance and support future advances in ML-assisted accelerator operations. Full article

(This article belongs to the Section Particle Detectors and Accelerators)

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22 pages, 14326 KB

Open AccessArticle

High-Resolution Quad-Channel Picoammeter: Characterization and Commissioning

by Lucas Yugo Tanio, Maurício Martins Donatti, Fernando Henrique Cardoso, Patricia Henriques Nallin, Vinicius Silva Oliveira, James Rezende Piton and Aline Ribeiro Passos

Instruments 2026, 10(2), 32; https://doi.org/10.3390/instruments10020032 - 9 Jun 2026

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Abstract

To address the high demand for precise low-current measurements at the Sirius’ beamlines, a quad-channel high-resolution Ethernet picoammeter has been designed. The instrument can measure currents ranging from femtoampere to milliampere across eight selectable ranges, featuring integrated analog-to-digital converters (ADCs), enabling sampling rates [...] Read more.

To address the high demand for precise low-current measurements at the Sirius’ beamlines, a quad-channel high-resolution Ethernet picoammeter has been designed. The instrument can measure currents ranging from femtoampere to milliampere across eight selectable ranges, featuring integrated analog-to-digital converters (ADCs), enabling sampling rates of up to 2 ksps and synchronization capabilities. This work describes the hardware design, the hardware handling procedures to achieve sub-picoampere resolution, and the characterization results of the instrument, considering the experimental results from Sirius beamlines. The designed device provides noise performance and gain accuracy that is comparable to high-end commercial solutions, proving its suitability for critical applications like on-the-fly scanning experiments. Special attention will be given to evaluating trigger latency, synchronization outcomes, as well as the device’s installation and commissioning at beamlines. Furthermore, we will deeply explore the interplay between the trigger period, digital filter bandwidth, and front-end analog bandwidth to optimize the signal-to-noise ratio in specific applications. The hardware project is publicly available in CERN’s open hardware repository. Full article

(This article belongs to the Section Particle Detectors and Accelerators)

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19 pages, 22996 KB

Open AccessFeature PaperArticle

Beyond Helium-3: Instruments for Cosmic-Ray Neutron Sensing Based on Boron-10 Neutron Detectors

by Markus Köhli and Jannis Weimar

Instruments 2026, 10(2), 31; https://doi.org/10.3390/instruments10020031 - 21 May 2026

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Abstract

Cosmic-Ray Neutron Sensing (CRNS) has become a standard method for non-invasive soil moisture monitoring at the field scale. With most CRNS sensors being derivatives from scientific nuclear equipment, the development of instruments based on alternative neutron detection technologies is a major development goal [...] Read more.

Cosmic-Ray Neutron Sensing (CRNS) has become a standard method for non-invasive soil moisture monitoring at the field scale. With most CRNS sensors being derivatives from scientific nuclear equipment, the development of instruments based on alternative neutron detection technologies is a major development goal for CRNS. We present a modular instrument family based on boron-10-lined proportional counters, specifically designed for long-term autonomous field operation. The system is controlled by a data logger supporting various telemetry options and external SDI-12 environmental sensors, while the frontend electronics use pulse-height and pulse-length information to suppress non-neutron background and electronic noise. Our results show high energy efficiency, with the latest generation close to 50 mW, allowing solar-powered operation even in challenging environments. The performance of the instruments is validated within long-term field deployments in different settings, showing that boron-10-based systems provide a scalable, low-power and cost-efficient alternative for the next generation of CRNS monitoring networks. Full article

(This article belongs to the Section Sensing Technologies and Precision Measurement)

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4 pages, 196 KB

Open AccessEditorial

Instrumentation and Measurement Methods for Industry 4.0 and IoT

by Mauro Serpelloni

Instruments 2026, 10(2), 30; https://doi.org/10.3390/instruments10020030 - 20 May 2026

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Abstract

The current industrial transformation is changing the way production systems are designed, manufactured, monitored, controlled, and maintained [...] Full article

(This article belongs to the Special Issue Instrumentation and Measurement Methods for Industry 4.0 and IoT)

8 pages, 3222 KB

Open AccessArticle

Design and Operation of a Flash Lamp for Vacuum Ultraviolet Light Production

by Silas Bosco, Jonas Bürgi, Livio Calivers, Richard Diurba, Johannes Furrer, Jan Kunzmann, Saba Parsa, Sascha Rivera, Nicolas Sallin, Camilla Tognina, Serhan Tufanli, Michele Weber and Dominik Wermelinger

Instruments 2026, 10(2), 29; https://doi.org/10.3390/instruments10020029 - 18 May 2026

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Abstract

Noble liquids, notably argon and xenon, are utilised as both detector media and as the detector target for dark matter and neutrino physics experiments. When the noble liquid is excited by particles, it scintillates vacuum ultraviolet light, which sensors then detect. A major [...] Read more.

Noble liquids, notably argon and xenon, are utilised as both detector media and as the detector target for dark matter and neutrino physics experiments. When the noble liquid is excited by particles, it scintillates vacuum ultraviolet light, which sensors then detect. A major focus of the detector development community is on producing precision light sensors for noble liquid detectors. We introduce a flash lamp to test VUV-sensitive light sensors with light at wavelengths observed using noble liquid detectors. This paper discusses the design and presents results from a flash lamp prototype operated at room temperature. Full article

(This article belongs to the Section Particle Detectors and Accelerators)

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31 pages, 12567 KB

Open AccessArticle

Development of a Cherenkov-Based Time-of-Flight Detector Using Silicon Photomultipliers

by Liliana Congedo, Giuseppe De Robertis, Antonio Di Mauro, Mario Giliberti, Francesco Licciulli, Antonio Liguori, Rocco Liotino, Leonarda Lorusso, Mario Nicola Mazziotta, Eugenio Nappi, Nicola Nicassio, Giuliana Panzarini, Roberta Pillera and Giacomo Volpe

Instruments 2026, 10(2), 28; https://doi.org/10.3390/instruments10020028 - 13 May 2026

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Abstract

The aim of this work is to develop high-precision time-of-flight (TOF) devices based on high-refractive-index solid Cherenkov radiators read out by silicon photomultipliers (SiPMs). Cherenkov light is prompt and, therefore, ideal for reaching the intrinsic timing limits of TOF systems. By utilizing a [...] Read more.

The aim of this work is to develop high-precision time-of-flight (TOF) devices based on high-refractive-index solid Cherenkov radiators read out by silicon photomultipliers (SiPMs). Cherenkov light is prompt and, therefore, ideal for reaching the intrinsic timing limits of TOF systems. By utilizing a thin, high-refractive-index radiator, a nearly instantaneous signal is generated by particles exceeding the Cherenkov threshold. In order to achieve the ultimate time resolution, we carried out a rigorous optimization of the radiator material and geometry, alongside the efficiency of the optical coupling to the SiPM sensors. The key factors limiting the time resolution were characterized by comprehensive Monte Carlo simulations, subsequently validated against experimental beam test data. We assembled small-scale prototypes instrumented with various Hamamatsu SiPM array sensors with active areas ranging from 1.3 to 3 mm, coupled with various window materials, such as fused silica and MgF₂, featuring various thickness values. The prototypes were successfully tested in beam test campaigns at the CERN-PS T10 beamline. The data were collected with a complete chain of front-end and readout electronics based on either the Petiroc 2A or the Radioroc 2 interfaced to a picoTDC to measure charges and times. By comparing the time measurements from two SiPM arrays, we were able to measure a time resolution better than 33.2 ps at the full system level, with a charged-particle detection efficiency of 100%. Our results demonstrate the expected performance benchmarks for the charged-particle detection efficiency and time resolution, and they highlight the potential of the developed Cherenkov-based TOF detectors for next-generation particle identification systems. Full article

(This article belongs to the Special Issue Silicon Photomultiplier-Based Systems for Particle and Radiation Detection)

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17 pages, 16277 KB

Open AccessArticle

Characterization and Performance Assessment of a SiPM-Based Muon Detector

by Luigi Cimmino, Fabio Ambrosino, Antonio Anastasio, Carla Aramo, Vincenzo Bottiglieri, David Iacopini, Vincenzo Masone, Marco Mirra, Gabor Nyitrai, Leopoldo Repola, Giulio Saracino and Vincenzo Tramontano

Instruments 2026, 10(2), 27; https://doi.org/10.3390/instruments10020027 - 5 May 2026

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Abstract

We present the upgrade and performance evaluation of a silicon photomultiplier (SiPM)-based muon detector, originally designed and developed 15 years ago for radiation tracking applications in radiographic imaging with cosmic muons. The first use of the original assembly and scientific objectives of the [...] Read more.

We present the upgrade and performance evaluation of a silicon photomultiplier (SiPM)-based muon detector, originally designed and developed 15 years ago for radiation tracking applications in radiographic imaging with cosmic muons. The first use of the original assembly and scientific objectives of the detector was in the Mu-Ray project of the Italian National Institute for Nuclear Physics (INFN) for muon radiographic imaging of volcanoes. In addition to its initial uses and after being upgraded with Hamamatsu SiPMs, the detector has been employed in a series of measurement campaigns for the detection of underground cavities. Herein we describe the mechanical recovery process and the integration of modern electronic components aimed at extending the operational capabilities of the detector, with particular attention to the adaptation of the front-end electronics to a new DAQ system. The results of the detector’s characterization and calibration under controlled conditions will be presented, evaluating its current performance and suitability for muography applications in a new geophysical setting. The results confirm that, despite aging, the system remains a viable instrument for precision and reliable muon tracking. Full article

(This article belongs to the Section Particle Detectors and Accelerators)

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31 pages, 2671 KB

Open AccessReview

Electrode Configurations for Electrical Bioimpedance-Based Pulse Wave Signal Acquisition: A Narrative Review

by Margus Metshein

Instruments 2026, 10(2), 26; https://doi.org/10.3390/instruments10020026 - 3 May 2026

Viewed by 626

Abstract

The pulsatile modulation of arterial blood carries essential information about the cardiovascular system and cardiac function—information that can be extracted through appropriate signal-processing algorithms. As wearable technologies are increasingly integrated into everyday life, measurement methods are required to be non-invasive and compact in [...] Read more.

The pulsatile modulation of arterial blood carries essential information about the cardiovascular system and cardiac function—information that can be extracted through appropriate signal-processing algorithms. As wearable technologies are increasingly integrated into everyday life, measurement methods are required to be non-invasive and compact in scale. Electrical bioimpedance (EBI) methods meet these wearability criteria well; however, they introduce uncertainties associated with the electrode–skin interface. This paper presents a targeted overview of electrode configurations for EBI-based pulse wave signal acquisition, focusing on non-invasive solutions suitable for wearable devices. Electrode configurations are examined with respect to major peripheral arteries in the human body that are accessible at the skin surface and suitable for regional impedance cardiography. The review includes a carefully selected set of references, drawing on both research literature and patent descriptions, and discusses the primary differences in how electrode configurations are presented across these sources. Full article

(This article belongs to the Special Issue Instrumentation and Measurement Methods for Industry 4.0 and IoT)

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12 pages, 2330 KB

Open AccessArticle

A Helium Ion Linear Accelerator Optimised for Astatine Production

by Maurizio Vretenar, Alessandra Lombardi and Lazar Nikitovic

Instruments 2026, 10(2), 25; https://doi.org/10.3390/instruments10020025 - 2 May 2026

Viewed by 399

Abstract

This paper presents the design of a linear accelerator optimised for the production of astatine-211, one of the most effective theragnostics isotopes for targeted alpha therapy of cancer (TAT). When attached to a carrier molecule that selectively binds to cancer cells, this powerful [...] Read more.

This paper presents the design of a linear accelerator optimised for the production of astatine-211, one of the most effective theragnostics isotopes for targeted alpha therapy of cancer (TAT). When attached to a carrier molecule that selectively binds to cancer cells, this powerful alpha emitter enables highly localised cell damage. The 11 m long linac is designed to accelerate an average current of up to 2 mA of fully stripped helium ions to 28.4 MeV, the energy required for ²¹¹At production on a bismuth target. The accelerator comprises an alpha particle source, a compact Radio Frequency Quadrupole (RFQ), and a Quasi-Alvarez Drift Tube Linac (QA-DTL). Compared with conventional cyclotron-based solutions, the proposed design provides higher beam current for increased isotope yield, together with reduced beam losses and activation. In addition, compared with a standard Drift Tube Linac (DTL) configuration, the adoption of a QA-DTL structure enables more compact dimensions and improved power efficiency. Full article

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15 pages, 1734 KB

Open AccessArticle

Systematic Characterisation and Non-Linear Response Correction of SiPMs Using the Single-Step Method for High-Precision Calorimetry

by Lukas Brinkmann, Massimiliano Antonello, Erika Garutti and Joern Schwandt

Instruments 2026, 10(2), 24; https://doi.org/10.3390/instruments10020024 - 24 Apr 2026

Viewed by 342

Abstract

Silicon photomultipliers (SiPMs) are vital for calorimetric applications in high-energy physics and medical imaging due to their high gain, compactness, and insensitivity to magnetic fields. However, their finite pixel count induces non-linear response behaviour at high photon fluxes, affecting energy resolution and systematic [...] Read more.

Silicon photomultipliers (SiPMs) are vital for calorimetric applications in high-energy physics and medical imaging due to their high gain, compactness, and insensitivity to magnetic fields. However, their finite pixel count induces non-linear response behaviour at high photon fluxes, affecting energy resolution and systematic accuracy. This work presents a comprehensive methodology to characterise SiPM response functions and derive correction curves using a single-step laser-based measurement approach. Three SiPMs with varying pixel sizes (15, 25 and 50 µm) are studied under controlled temperature conditions, with response functions extracted across different overvoltages and integration windows. The correction method, independent of precise light source calibration, effectively linearises the response up to saturation levels exceeding 100% of the pixel count, achieving deviations of the order of 3% across a broad operational parameter space, and outperforming the traditional calibration model. The analysis demonstrates minimal dependence of the correction on temperature, overvoltage, and pixel size, indicating universal applicability. These findings enhance SiPM performance in high-energy calorimetry and offer a practical framework for improving detector linearity and dynamic range extensions in large-scale applications. Full article

(This article belongs to the Special Issue Silicon Photomultiplier-Based Systems for Particle and Radiation Detection)

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21 pages, 12324 KB

Open AccessArticle

Wireless Instrumented Ankle Foot Orthosis (AFO) for Gait Cycle Monitoring

by Soufiane Mahraoui and Mauro Serpelloni

Instruments 2026, 10(2), 23; https://doi.org/10.3390/instruments10020023 - 22 Apr 2026

Cited by 1 | Viewed by 762

Abstract

Ankle–foot orthoses (AFOs) are widely used in the rehabilitation of patients with neurological or musculoskeletal disorders. However, treatment outcomes may be influenced by incorrect use of the device or by inappropriate orthosis selection. Since many types of AFOs are available, differing in materials, [...] Read more.

Ankle–foot orthoses (AFOs) are widely used in the rehabilitation of patients with neurological or musculoskeletal disorders. However, treatment outcomes may be influenced by incorrect use of the device or by inappropriate orthosis selection. Since many types of AFOs are available, differing in materials, stiffness, and geometry, an objective evaluation tool can support clinical decision-making. This work presents the design, development, and characterization of an instrumented AFO able to quantify relevant gait parameters in an objective way. The proposed device integrates three measurement modalities in a compact wearable structure. Two longitudinal strain gauges estimate ankle plantar- and dorsiflexion angles. Two force-sensitive elements detect foot–ground contact and allow identification of stance and swing phases of the gait cycle. A single inertial measurement unit (IMU) is used to measure lateral shank inclination. The strain-gauge-based angle estimation was validated against a gold-standard motion capture system, achieving a root mean square error of approximately 1.6 degrees and showing higher accuracy than the IMU for plantar/dorsiflexion measurement, while maintaining a simple electronic architecture. The force sensors were validated using a force platform and demonstrated reliable detection of loading and unloading events. Monitoring lateral inclination through the single IMU provides additional information related to balance and potential fall risk. Data are transmitted via Bluetooth Low Energy (BLE) to a custom Python-based application for real-time visualization and recording. Overall, the results validate the electronic instrumentation and demonstrate reliable system performance, indicating that the proposed instrumented AFO represents a promising platform for objective gait assessment and future clinical applications. Full article

(This article belongs to the Special Issue Instrumentation and Measurement Methods for Industry 4.0 and IoT)

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15 pages, 5175 KB

Open AccessArticle

Design and Characterization of a Low-Current Compact Extraction and Matching System for a High-Frequency RFQ in Medical Applications

by Aristeidis Mamaras, Francesco Di Lorenzo, Alessandra Lombardi, Eleonora Pasino and Dimitrios Sampsonidis

Instruments 2026, 10(2), 22; https://doi.org/10.3390/instruments10020022 - 6 Apr 2026

Viewed by 573

Abstract

A low-current compact extraction and matching system has been designed and experimentally tested to evaluate its capability for direct proton injection of 15 keV into a 750 MHz radiofrequency quadrupole for medical applications. The design methodology combined 2D and 3D layouts, supported by [...] Read more.

A low-current compact extraction and matching system has been designed and experimentally tested to evaluate its capability for direct proton injection of 15 keV into a 750 MHz radiofrequency quadrupole for medical applications. The design methodology combined 2D and 3D layouts, supported by detailed electrostatic simulations. First experimental results are reported, including beam current characterization and irradiation measurements under varying operating conditions. These results are benchmarked against simulation data to provide a preliminary evaluation of system performance. Ongoing efforts focus on extending the experimental campaign to consolidate these findings. A comparative study with a gridded-lens-based extraction and transport system is also being conducted to achieve reliable matching of high-quality beams to high-frequency RFQs for clinical implementation. Full article

(This article belongs to the Special Issue Compact Accelerators)

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17 pages, 20220 KB

Open AccessArticle

Observational Technological Innovations and Future Development of the Lijiang Coronagraph

by Xuefei Zhang, Yu Liu, Tengfei Song, Mingyu Zhao, Xiaobo Li, Mingzhe Sun, Feiyang Sha and Xiande Liu

Instruments 2026, 10(2), 21; https://doi.org/10.3390/instruments10020021 - 3 Apr 2026

Viewed by 467

Abstract

As a core ground-based coronal observation facility in the low-latitude and high-altitude regions of China, the Lijiang Coronagraph takes advantage of the natural endowments of the Lijiang Astronomical Observation Station, such as an altitude of 3200 m and low atmospheric turbulence. It has [...] Read more.

As a core ground-based coronal observation facility in the low-latitude and high-altitude regions of China, the Lijiang Coronagraph takes advantage of the natural endowments of the Lijiang Astronomical Observation Station, such as an altitude of 3200 m and low atmospheric turbulence. It has gone through a complete development process from introduction through Chinese–Japanese cooperation to independent innovation and iteration. This paper systematically summarizes the core technological innovation achievements of this facility, including the upgrade of the automatic operating system, the integration of the dual-band observation system, the stray light suppression technology based on the image difference method before and after cleaning, and the high-precision image calibration and registration technology. These innovations have significantly improved observation efficiency and data quality, laying a solid foundation for high-quality observations. At the scientific research level, the observation data reveal that 1.1 R_⊙ (solar radius) is a highly correlated region between coronal green line brightness and magnetic field intensity. This study also confirms a strong correlation between the coronal green line and the SDO/AIA 211 Å extreme ultraviolet band (correlation coefficient: 0.89–0.99), which can support the research on early warning of Coronal Mass Ejections (CMEs). These achievements provide key data support for the verification of coronal heating mechanisms and the exploration of the origin of the slow solar wind. The technical experience accumulated from the Lijiang Coronagraph has not only laid a solid foundation for the research and development of China’s next-generation large-aperture coronagraphs, but also facilitated and accelerated substantial progress in China’s technical capabilities for low coronal observation, enabling the country to establish internationally parallel competitive capabilities in this field. This system has also become an important part of the global coronal observation network. Full article

(This article belongs to the Special Issue Instruments for Astroparticle Physics)

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13 pages, 2948 KB

Open AccessArticle

Cyclotron Production and Purification of ⁸³Sr as a ⁹⁰Sr Substitute for Positron Emission Tomography (PET)

by Marcel Lindemann, Jann Schöngart, Jan Štursa and Karsten Franke

Instruments 2026, 10(2), 20; https://doi.org/10.3390/instruments10020020 - 30 Mar 2026

Viewed by 746

Abstract

Radioactive contaminations in soil, which originate from nuclear power production, nuclear weapon testing, or uncontrolled release, are of great environmental concern. One of the major fission product contaminants is ⁹⁰Sr, whose high mobility demands a method to track contamination pathways and remediation [...] Read more.

Radioactive contaminations in soil, which originate from nuclear power production, nuclear weapon testing, or uncontrolled release, are of great environmental concern. One of the major fission product contaminants is ⁹⁰Sr, whose high mobility demands a method to track contamination pathways and remediation processes. Positron emission tomography (PET) is a valuable tool for the required studies. As a β⁻/γ-emitter, ⁹⁰Sr is not suitable for PET, which requires β⁺-emitters. As an alternative, ⁸³Sr, with a 12% intensity of β⁺-emission and a half-life of 32.4 h, is an appropriate PET substitute for ⁹⁰Sr. We produced ⁸³Sr with an enriched target of [⁸⁵Rb]RbCl in a ⁸⁵Rb(p,3n)⁸³Sr reaction. The target material was bombarded with 36.22 MeV protons (ø 1.78 µA, 315 min), at a solid target station at the cyclotron U-120M (NPI CAS). The irradiated target (1.5 GBq) was dissolved in water, evaporated to dryness, redissolved in nitric acid, and transferred onto a Sr-selective cartridge (Sr-SpecTM, TRISKEM, France). Following target material wash out, ⁸³Sr elution with water, solvent evaporation, and reformulation (in dilute nitric acid) yielded 1.2 GBq (82% radiochemical extraction efficiency, non-decay-corrected) of an ⁸³Sr-solution. The easy and fast method is able to produce non-carrier-added ⁸³Sr with high radionuclidic purity. Full article

(This article belongs to the Special Issue Selected Papers from the 16th Workshop of the European Network of Research Cyclotrons (CYCLEUR 2025))

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20 pages, 13968 KB

Open AccessArticle

Design and Characterization of the POKERINO Prototype for the POKER/NA64 Experiment at CERN

by Andrei Antonov, Pietro Bisio, Mariangela Bondì, Andrea Celentano, Anna Marini and Luca Marsicano

Instruments 2026, 10(2), 19; https://doi.org/10.3390/instruments10020019 - 27 Mar 2026

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Abstract

The NA64 experiment at the CERN H4 beamline recently started a high-energy positron-beam program to search for light dark matter particles through a thick-target, missing-energy measurement. To fulfill the energy resolution requirement of the physics measurement [...] Read more.

The NA64 experiment at the CERN H4 beamline recently started a high-energy positron-beam program to search for light dark matter particles through a thick-target, missing-energy measurement. To fulfill the energy resolution requirement of the physics measurement

σ_{E} / E ≃ 2.5 % / \sqrt{E [GeV]} \oplus 0.5 %

and cope with the constraints and performance requests of the NA64 setup, a new high-resolution homogeneous electromagnetic calorimeter PKR-CAL has been designed. The detector is based on PbWO₄ crystals, each read by multiple SiPM sensors to maximize the light collection. The PKR-CAL design has been optimized to mitigate and control unavoidable SiPM saturation effects at high light levels, as well as to minimize the gain fluctuations induced by instantaneous variations of the H4 beam intensity. The R&D program culminated in the construction of a small-scale prototype, POKERINO. In this work, we present the results from the experimental characterization campaign of the POKERINO, aiming at demonstrating that the obtained performances are compatible with the application requirements. Full article

(This article belongs to the Special Issue Silicon Photomultiplier-Based Systems for Particle and Radiation Detection)

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