A reliable and highly scalable Internet of Things (IoT) end-to-end data infrastructure has been developed for environmental radiation monitoring at CERN based on a Low-Power Wide-Area Network (LPWAN). The proposed system,called W-MON (Waste radiation MONitoring), consists of an interconnected network of thousands of highly sensitive and ultra-low power gamma radiation sensors acting as LoRa transceivers. The aim of the system is to improve and automatize the radiological controls of conventional waste containers. The end-devices measure the radiation levels in the waste containers on a continuous basis and send the data periodically to the LoRaWAN network server. The network has been deployed in an outdoor environment covering hundreds of hectares. A set of web-based user applications for real-time monitoring, data visualization and status control of the devices have been designed based on open source tools. The data pipeline infrastructure has been designed to allow an easy integration into REMUS, the overall CERN Radiation and Environment Monitoring Unified Supervision service.

Structural health monitoring using noninvasive methods is one of the major challenges that aerospace manufacturers face in this decade. Our work in this field focuses on the development and the system integration of millimetric piezoelectric sensors/ actuators to generate and measure specific guided waves. The aim of the application is to detect mechanical flaws on complex composite and alloy structures to quantify efficiently the global structures’ reliability. The study begins by a physical and analytical analysis of a piezoelectric patch. To preserve the structure’s integrity, the transducers are directly pasted onto the surface which leads to a critical issue concerning the interfacing layer. In order to improve the reliability and mitigate the influence of the interfacing layer, the global equations of piezoelectricity are coupled with a load transfer model. Thus we can determine precisely the shear strain developed on the surface of the structure. To exploit the generated signal, a high precision analog charge amplifier coupled to a double T notch filter were designed and scaled. Finally, a novel joined time-frequency analysis based on a wavelet decomposition algorithm is used to extract relevant structures signatures. Finally, this paper provides examples of application on aircraft structure specimens and the feasibility of the system is thus demonstrated.

The work reported on this paper describes a new methodology implementation for active structural health monitoring of recent aircraft parts made from carbon-fiber-reinforced polymer. This diagnosis is based on a new embedded method that is capable of measuring the local high frequency impedance spectrum of the structure through the calculation of the electro-mechanical impedance of a piezoelectric patch pasted non-permanently onto its surface. This paper involves both the laboratory based E/M impedance method development, its implementation into a CPU with limited resources as well as a comparison with experimental testing data needed to demonstrate the feasibility of flaw detection on composite materials and answer the question of the method reliability. The different development steps are presented and the integration issues are discussed. Furthermore, we present the unique advantages that the reconfigurable electronics through System-on-Chip (SoC) technology brings to the system scaling and flexibility. At the end of this article, we demonstrate the capability of a basic network of sensors mounted onto a real composite aircraft part specimen to capture its local impedance spectrum signature and to diagnosis different delamination sizes using a comparison with a baseline.

The European Organization for Nuclear Research (CERN) has the legal obligation to protect the public and the people working on its premises from any unjustified exposure to ionising radiation. In this context, radiation monitoring is one of the main concerns of the Radiation Protection Group. After 30 y of reliable service, the ARea CONtroller (ARCON) system is approaching the end of its lifecycle, which raises the need for new, more efficient radiation monitors with a high level of modularity to ensure better maintainability. Based on these two main principles, new detectors are currently being developed that will be capable of measuring very low dose rates down to 50 nSv h⁻¹, whilst being able to measure radiation over an extensive range of 8 decades without any auto scaling. To reach these performances, CERN Radiation MOnitoring Electronics (CROME), the new generation of CERN radiation monitors, is based on the versatile architecture that includes new read-out electronics developed by the Instrumentation and Logistics section of the CERN Radiation Protection Group as well as a reconfigurable system on chip capable of performing complex processing calculations. Beside the capabilities of CROME to continuously measure the ambient dose rate, the system generates radiation alarms, provides interlock signals, drives alarm display units through a fieldbus and provides long-term, permanent and reliable data logging. The measurement tests performed during the first phase of the development show very promising results that pave the way to the second phase: the certification.

Radiation detectors need front-end electronics capable of measuring currents over a large dynamic range with femtoampere sensitivity. The goal of this work is to find an alternative to the legacy systems implemented using discrete components or technology nodes of 350 nm or higher. The 130 nm technology is evaluated on its leakage current performance to assess its employability in such applications. A comparative analysis of three low current measurement topologies, namely the charge balancing, reset counting, and direct slope measurement methods, is carried out and their performance in different current ranges is evaluated. The charge balancing method was found to provide a better dynamic range with greater accuracy. However, in the lower current range, the direct slope measurement method was found to give faster results than the other two methods with comparable accuracy. Also, an application-specific integrated circuit implementing the charge balancing method was found to be linear throughout the dynamic range of −1 fA to $-1\,\,\mu \text{A}$ and could measure currents with an accuracy of ±7%. This achievement in the 130 nm technology opens the way to using the high-speed digital cells offered by this technology in conjunction with the low-leakage transistors to design a high-speed accurate current measurement system.