Instruments

19 pages, 3120 KB

Open AccessArticle

Development and Integration of the NA64-DTC Automation Controller for the CERN “DESY Table” Motorized Platform

by Andrei Antonov, Andrea Celentano, Anna Marini and Luca Marsicano

Instruments 2026, 10(3), 41; https://doi.org/10.3390/instruments10030041 - 10 Aug 2026

A remote automation controller NA64-DTC was developed, constructed, and integrated for the so-called “DESY Table” motorized platform, widely used in CERN East-Area and North-Area experimental installations. The device interfaces with the table manual control panel through a signal duplication connector, enabling remote operation [...] Read more.

A remote automation controller NA64-DTC was developed, constructed, and integrated for the so-called “DESY Table” motorized platform, widely used in CERN East-Area and North-Area experimental installations. The device interfaces with the table manual control panel through a signal duplication connector, enabling remote operation without modifications to the original hardware. Button commands are emulated using opto-isolated switches, allowing seamless coexistence with the standard manual control system. The controller is based on an ESP32-C3 System-on-Module and hosts an HTTP server that provides a simple and flexible interface for experiment-specific integration and automation. The system was successfully commissioned at CERN using the PS-T9 and SPS-H4 beamline facilities. A positioning accuracy of approximately

0.2

mm and

0.3

mm was achieved over the full movement range of the vertical and horizontal table axes, respectively, with the residual positioning error dominated by the finite inertia of the platform. The device was operated continuously for more than two months without any observed failures or communication errors. Although originally developed for the NA64 experiment, the proposed solution is applicable to any CERN installation employing the DESY Table platform. This work describes in detail the device technical design and operation, as well as the performances obtained during the commissioning. Full article

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

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32 pages, 3679 KB

Open AccessArticle

Feasibility Study of Beam Loss Energy Estimation with an Optical Fibre-Based Detector

by Angus Jones, Joseph Wolfenden, Montague King, Antonio Gilardi, Lauryn Eley and Carsten P. Welsch

Instruments 2026, 10(3), 40; https://doi.org/10.3390/instruments10030040 - 31 Jul 2026

Abstract

Optical fibre beam loss monitors (oBLMs) are in use at several accelerator facilities worldwide as an online, low-cost, and reliable beam loss monitoring solution. They measure beam loss locations through time-of-flight analysis of Cherenkov radiation produced in optical fibres by relativistic particle showers [...] Read more.

Optical fibre beam loss monitors (oBLMs) are in use at several accelerator facilities worldwide as an online, low-cost, and reliable beam loss monitoring solution. They measure beam loss locations through time-of-flight analysis of Cherenkov radiation produced in optical fibres by relativistic particle showers from beam loss events. They offer continuous accelerator coverage and can attain a beam loss location precision of 1 m or better. The recirculating multi-energy particle beams of energy recovery LINACs present difficulties in tracking losses from beam bunches throughout their journey in the machine. A potential solution is offered through estimation of the beam loss energy from the measured intensity of the oBLM signal, which could be used to determine the beam bunches associated with each loss signal. Monte Carlo simulations of beam loss interaction with the oBLM were performed in Geant4 to qualitatively investigate the feasibility of this method. The most feasible scenario occurs when the percentage change in the number of lost particles (loss intensity) from two beam losses is less than half of their corresponding percentage energy change. Otherwise, a complementary means of determining loss intensity is recommended for this method. Additionally, the relationship between beam energy and oBLM signal intensity was found to vary strongly with beam loss position relative to the fibre. Measurements were collected from the oBLM system installed at CLEAR, CERN; qualitative agreement was observed with the simulations, although quantitative analysis was not possible. Simulations were therefore identified as a critical component of oBLM energy estimation—to determine the expected behaviours of the oBLM signal on an accelerator and guide the analysis and interpretation of the intensity measurements. Full article

(This article belongs to the Special Issue Selected Papers from the International Beam Instrumentation Conference (IBIC) Series)

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Graphical abstract

18 pages, 1499 KB

Open AccessArticle

Automation for High-Availability Bunch Arrival Time Monitors

by Jiri Kral, Jens Georg and Raimund Kammering

Instruments 2026, 10(3), 39; https://doi.org/10.3390/instruments10030039 - 24 Jul 2026

Abstract

Electro-optical bunch arrival time measurement is a method to monitor the timing of bunches in predominantly linear electron accelerators to below femtosecond precision. Despite the method being well established, a stable and fully available measurement was reported only recently. DESY’s free-electron lasers FLASH [...] Read more.

Electro-optical bunch arrival time measurement is a method to monitor the timing of bunches in predominantly linear electron accelerators to below femtosecond precision. Despite the method being well established, a stable and fully available measurement was reported only recently. DESY’s free-electron lasers FLASH and EuXFEL feature Bunch Arrival Time (BAM) diagnostics that serve as a standard operation data source for the facility’s longitudinal fast and slow stabilization, as well as an instrument available to the users for pump laser alignment and offline analysis. A comprehensive upgrade and R&D effort targeting the performance of DESY’s BAM was carried out in recent years. The complexity of the device poses challenges to its control layer, calibration, drift control, and operation setup. Solving these proved to be essential in reaching operational stability and high availability. We report on the updates to the BAM controls and the development of automation of numerous tasks that contributed a great deal to achieving long-term stability and full run availability. Full article

(This article belongs to the Special Issue Selected Papers from the International Beam Instrumentation Conference (IBIC) Series)

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23 pages, 3528 KB

Open AccessArticle

High-Precision Static Calibration of Capacitive Sensing in Inertial Sensors via Image-Based Displacement Measurement and Bias Modeling

by Junxiang Li, Dongxu Liu, Wenqi Pan, Shaoxin Wang, Keqi Qi and Peng Dong

Instruments 2026, 10(3), 38; https://doi.org/10.3390/instruments10030038 - 4 Jul 2026

Abstract

Space gravitational wave detection missions demand ultra-stable calibration of inertial sensor capacitive sensing. Conventional dynamic methods suffer from mechanical vibration noise and bias separation difficulties, while large-displacement operation introduces pronounced nonlinearity. This work proposes a static calibration method using an image-based displacement measurement [...] Read more.

Space gravitational wave detection missions demand ultra-stable calibration of inertial sensor capacitive sensing. Conventional dynamic methods suffer from mechanical vibration noise and bias separation difficulties, while large-displacement operation introduces pronounced nonlinearity. This work proposes a static calibration method using an image-based displacement measurement system to establish a vibration-free benchmark. A subpixel edge detection algorithm locates the Test Mass and Electrode Housing edges with a repeatability of approximately 0.05 pixels, and the Test Mass geometry is independently calibrated by a Coordinate Measuring Machine (CMM, ±2 µm,

k = 2

) to provide SI traceability. A nonlinear calibration model incorporating higher-order Taylor terms is developed, combined with a forward/reverse connection technique for composite bias modeling. Experimental validation at

x_{0} = 665

µm (

x_{0} / d_{0} \approx 0.665

) demonstrated a gain coefficient repeatability of 0.01658% RMSPER and a combined expanded uncertainty of

U \approx 2.18 \times 10^{- 5}

1 / µ m

(

k = 2

). Intended as a complementary ground-based technique to dynamic calibration, this method avoids dynamic excitation-induced noise while establishing complete SI traceability, offering a reliable solution for ground validation and long-term monitoring of space inertial sensors. Full article

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

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9 pages, 1873 KB

Open AccessArticle

Methodology for Harmonic Distortion Characterization and Modelling of GaN HEMT Varactors

by Loukas Chevas, Matthias Bucher, Nikolaos Makris, Ioannis Spiridon Fosteris, Nikolaos Fasarakis, Antonios Stavrinidis, Maria Kayambaki, Athanasios Kostopoulos and George Konstantinidis

Instruments 2026, 10(3), 37; https://doi.org/10.3390/instruments10030037 - 3 Jul 2026

Abstract

The bias-dependent capacitance of varactors can introduce harmonic distortion into the circuits where they are utilized. A gate capacitance model valid through inversion–depletion has been presented for GaN HEMT varactors in the drive for their utilization in monolithic GaN ASICs. This work focuses [...] Read more.

The bias-dependent capacitance of varactors can introduce harmonic distortion into the circuits where they are utilized. A gate capacitance model valid through inversion–depletion has been presented for GaN HEMT varactors in the drive for their utilization in monolithic GaN ASICs. This work focuses on the circuit and the methodology employed to accurately measure on wafer the harmonic distortion caused by one such device. The circuit is presented and its design considerations and operation trade-offs are discussed, followed by a presentation of the measurements resulting from its use. Second- and third-order harmonic distortion is recorded and presented, with Verilog-A model simulations used to fit the measured data. The model consists of a charge-based expression of the HEMT varactor capacitance, with a minimal number of parameters. The good fit of the model is demonstrated, proving both the suitability of the circuit used for the measurements and the validity of the capacitance model for real-world applications. Full article

(This article belongs to the Special Issue Microelectronics and Photonics Design, Technology and Instrumentation)

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20 pages, 5232 KB

Open AccessArticle

Prototype Scintillating-Fiber SiPM-Based Beam Monitor for Conventional and FLASH Proton Therapy

by Georgios Mystridis, Fabio Acerbi and Benedetto Di Ruzza

Instruments 2026, 10(3), 36; https://doi.org/10.3390/instruments10030036 - 2 Jul 2026

Abstract

The development of FLASH particle therapy, especially proton therapy, characterized by ultra-high dose rates (>40 Gy/s), presents significant challenges for dosimetry and beam monitoring. For example, ionization chambers (ICs) exhibit charge recombination effects leading to saturation, and other passive detectors cannot be used [...] Read more.

The development of FLASH particle therapy, especially proton therapy, characterized by ultra-high dose rates (>40 Gy/s), presents significant challenges for dosimetry and beam monitoring. For example, ionization chambers (ICs) exhibit charge recombination effects leading to saturation, and other passive detectors cannot be used for real-time monitoring. This paper presents the idea, simulations and the preliminary prototype of a scintillating-fibers SiPM-based dosimeter for both high-flux and conventional dose-rate proton beam therapy. The prototype is based on 1 mm diameter plastic scintillating fibers, coupled to Silicon Photomultipliers (SiPMs). We estimated the interactions and the produced light signal within the fibers by the protons and towards the photodetectors using a semi-analytical model combining SRIM and analytical calculations. We estimated a light signal reaching the SiPMs in the range of 10⁷–10¹¹ photons (in a 50 ms beam pulse), for proton energies in the range 70–228 MeV, between the minimum and maximum beam current levels for conventional and FLASH conditions. Results highlight the very large dynamic range needed to be compatible with conventional and FLASH regimes. We also evaluated the linearity limits of the SiPMs and of the scintillating fibers. Finally, we preliminarily validated a reduced prototype version with a proton beam, demonstrating a good linearity of the system. Full article

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

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18 pages, 3098 KB

Open AccessArticle

Invasiveness Study of Supersonic Gas-Curtain-Based Ionization Profile Monitor for Medical Accelerators

by William Butcher, Narender Kumar, Milaan Patel, Bharat Singh Rawat, Oliver Stringer, Farhana Thesni Mada Parambil, Hao Zhang and Carsten P. Welsch

Instruments 2026, 10(3), 35; https://doi.org/10.3390/instruments10030035 - 30 Jun 2026

Abstract

In proton beam therapy, ideally, beam monitoring should be non-invasive to provide online real-time feedback, such that the total dose delivered to the patient is not significantly affected. The invasiveness of the Supersonic Gas-Curtain-Based Ionization Profile Monitor (SGC-IPM) system was quantified by perturbation [...] Read more.

In proton beam therapy, ideally, beam monitoring should be non-invasive to provide online real-time feedback, such that the total dose delivered to the patient is not significantly affected. The invasiveness of the Supersonic Gas-Curtain-Based Ionization Profile Monitor (SGC-IPM) system was quantified by perturbation in beam current and transverse beam profile parameters induced by the supersonic gas-curtain for a 4.9–5.3 keV electron beam, representing a worst-case scenario where perturbations can be more easily observable. The experimentally measured gas-curtain effects on transverse beam parameters (≤2%), intensity (≤−1%) and beam current (≤−1%) were small in magnitude and largely below resolution limits. To confirm these effects, order-of-magnitude beam–gas interaction approximations were calculated for the experimental energy range, demonstrating negligible energy loss with minor scattering, broadly consistent with the experimental results. Clinical proton beam gas-curtain predictions (70–250 MeV) indicate a further reduction of ∼

10^{4}

compared to the experimental observations. Even under the conservative electron beam conditions used in this study, the observed perturbations were minor or unresolvable and measured effects were significantly smaller than spatial and dosimetry scales relevant to proton radiotherapy. Overall, the experimental measurements and supporting order-of-magnitude estimates demonstrate that the SGC-IPM introduces negligible perturbations to beam parameters and is predicted to provide non-invasive beam profile monitoring for clinical proton beam diagnostics. Full article

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

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24 pages, 3151 KB

Open AccessArticle

A Unified Beam-Dynamics and Hardware Design Framework for Hybrid Nonlinear-Kicker Injection in NSLS-II

by Xi Yang and Patrick N’Gotta

Instruments 2026, 10(3), 34; https://doi.org/10.3390/instruments10030034 - 26 Jun 2026

Abstract

Nonlinear kickers (NLKs) enable off-axis injection in ultralow-emittance storage rings by providing a strong kick to the injected beam while remaining nearly transparent to the stored beam. In hybrid schemes, a conventional four-kicker bump defines the injected trajectory, and the NLK reduces the [...] Read more.

Nonlinear kickers (NLKs) enable off-axis injection in ultralow-emittance storage rings by providing a strong kick to the injected beam while remaining nearly transparent to the stored beam. In hybrid schemes, a conventional four-kicker bump defines the injected trajectory, and the NLK reduces the first-turn action under constrained beam offset and optics conditions. Effective operation additionally requires stable and reproducible first-turn injection trajectories. We develop a compact action–angle framework that expresses NLK dynamics in terms of Courant–Snyder invariants and yields an analytical bound on achievable action reduction. This formulation provides direct design rules for NLK placement, phase advance, injected-beam offset, and kicker field profile. Within this framework, we identify the 8-wire NLK as a practical baseline and extend its design by relaxing the square-geometry constraint, enabling inward shifting of the off-axis field peak while preserving on-axis field and gradient cancellation. Application to the NSLS-II lattice shows how aperture, pulsed-power, and mechanical constraints combine to determine a coupled design solution. Multi-turn tracking confirms that candidate NLK locations maintain sufficient stay-clear (aperture-clearance) margin, while the optimized wire geometry reduces the required current and Lorentz force load. The results establish a unified approach for NLK-assisted injection design and provide a practical pathway for upgrades in diffraction-limited storage rings. Full article

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

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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

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

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

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

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

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

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

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

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

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

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 2

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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