Technical Proposal for FASER: ForwArd Search ExpeRiment at the LHC

FASER is a proposed small and inexpensive experiment designed to search for light, weakly-interacting particles during Run 3 of the LHC from 2021-23. Such particles may be produced in large numbers along the beam collision axis, travel for hundreds of meters without interacting, and then decay to standard model particles. To search for such events, FASER will be located 480 m downstream of the ATLAS IP in the unused service tunnel TI12 and be sensitive to particles that decay in a cylindrical volume with radius R=10 cm and length L=1.5 m. FASER will complement the LHC's existing physics program, extending its discovery potential to a host of new, light particles, with potentially far-reaching implications for particle physics and cosmology. This document describes the technical details of the FASER detector components: the magnets, the tracker, the scintillator system, and the calorimeter, as well as the trigger and readout system. The preparatory work that is needed to install and operate the detector, including civil engineering, transport, and integration with various services is also presented. The information presented includes preliminary cost estimates for the detector components and the infrastructure work, as well as a timeline for the design, construction, and installation of the experiment.Comment: 82 pages, 62 figures; submitted to the CERN LHCC on 7 November 201

A Radiation tolerant acquisition system and signal processing for LVDT sensors.

This thesis work aims at designing a new electronic board which wants to be a generic acquisition card with numerical processor capabilities for reading LVDT or other position sensors. The board is based on commercial parts and is designed to be radiation tolerant . That means that the electronics works properly up a given limit of radiation levels. A flash based FPGA, known to be latch-up free, is selected to perform the Sine Fit algorithm in fixed point precision to retrieve the sensor position. The Sine Fit algorithm is deeply analyzed and 3 different implementations in fixed point representation are investigated in order to achieve a numerical precision that can assure the target requirements. The third algorithm makes use of the CORDIC functions. The tests are done on a proof demonstrator board with ADC and FPGA

La nouvelle version du système de monitorage des radiations pour l'électronique au CERN : garantie de tenue aux radiations des composants électroniques et qualication des capteurs

The measurement of the radiation levels is an essential requirement in the LHC and its injection lines in order to quantify radiation effects on electronics and provide a detailed knowledge of the radiation field. The radiation monitoring system for the electronics at CERN, the “RadMon'', was installed in critical areas where equipment is or will be placed. Issues experienced in the last years of Radmon operation, the obsolescence of a few fundamental components of the electronic board and the necessity to improve both the accuracy and the resolution of measurements led to the launch of a new design of the monitor.This work describes the architecture of the new RadMon (V6), its reliability in radiation environments and the strategy adopted to choose and qualify the sensors, used for monitoring the mixed radiation field of the LHC accelerators. The CERN guidelines were adopted to qualify the RadMon components under radiation in order to develop a new architecture both more tolerant to radiation and more versatile than that of the previous version. In this context, the challenges that radiation tests impose for measuring Single Event Effects (SEUs) on a complex mixed-signal component such as the Analog to Digital converter, led to the development of an innovative test technique, which will be described in this thesis.The reliability of the RadMon measurements strongly depends on the calibration of its sensors. The complex radiation environment of the LHC imposes a peculiar qualification process which will be described and discussed in this work for the RadFets (Total Ionizing Dose sensor) and the SRAM memories (High Energy Hadrons fluence sensor).The use of the RadFet in a mixed field radiation environment has been studied and analyzed by means of 60Co sources as well as proton beams at different energies.The RadFets have been re-calibrated by studying the dose rate, particle sources, temperature, annealing and fading effects as a function of the oxide thickness. Furthermore, thanks to the new architecture of the RadMon, new biasing configurations have been tested to improve the resolution.Two types of SRAM memories with technology nodes of 400 and 90nm have been tested and calibrated by following a strict qualification methodology which includes tests with protons in the range 30-400 MeV, and with neutrons from thermal energies up to intermediate energies (~14 MeV). The 90nm memory improves the accuracy and resolution of the hadron fluence measurement. Moreover, the simultaneous use of both types of memories permits an improvement on the accuracy of the thermal neutron detection with respect to the previous version, as a result of a procedure which will be detailed in this work.The efforts towards the improvement of the TID measurements resolution for the new RadMon lead to the research and study of a new type of dosimeter sensor: the Floating Gate dosimeter (FGDOS). The sensor embeds complex circuitry, thus a full radiation qualification was necessary. Mixed field radiation tests, 60Co and protons tests have been carried out in order to evaluate the performance and the possible issues of the sensor. In this context, an analytical model of the sensor was developed to prove that the floating gate structure can be used as charge yield measurement instrument at room temperature and at low electric fields.The radiation tolerance characterization of the hardware, the qualification and calibration process of the sensors have significantly improved the overall reliability and quality of the measurements of the new RadMon. These improvements turned it into a reference instrument for radiation monitoring of complex mixed fields, such as the one encountered in the LHC, its injectors chain, and other particle physics research centers, such as JLAB in US, J-PARC in Japan.La mesure des niveaux de rayonnement est une exigence essentielle dans le LHC et ses lignes d'injection afin de quantifier les effets des radiations sur l'électronique et de fournir une connaissance détaillée du champ de rayonnement. Le système de surveillance des rayonnements pour l'électronique au CERN, le "RadMon '', a été installé dans les zones critiques où l'équipement est ou sera placé. Les problèmes rencontrés au cours des dernières années d'utilisation du Radmon, et la nécessité d'améliorer la précision et la résolution des mesures a conduit au lancement d'une nouvelle conception du moniteur.Ce travail décrit l'architecture du nouveau RadMon (V6), sa fiabilité dans les environnements radiatifs et de la stratégie adoptée pour choisir et qualifier les capteurs utilisés pour surveiller le champ de rayonnement mixte des accélérateurs du LHC. Les directives du CERN ont été adoptées pour qualifier les composants RadMon sous rayonnement afin de développer une nouvelle architecture à la fois plus tolérante au rayonnement et plus polyvalente que celui de la version précédente. Dans ce contexte, les défis que les tests de rayonnement imposent pour mesurer les Single Event Upsets (SEUs) sur un composant complexe à signaux mixtes tels que le convertisseur analogique-numérique, ont conduit au développement d'une technique de test innovant, qui sera décrit dans cette thèse.L'environnement radiatif complexe du LHC impose un processus de qualification particulier qui sera décrit et discuté dans ce travail pour les RadFets (capteur dose ionisante) et les mémoires SRAM (capteur de fluence High Energy Hadrons).L'utilisation du RadFet dans un champ mixte de rayonnement a été étudié et analysé au moyen de sources de 60Co et de faisceaux de protons de différentes énergies.Les RadFets ont été ré-étalonné en étudiant le débit de dose, les sources de particules, la température, la guérison thermique en fonction de l'épaisseur d'oxyde. En outre, grâce à la nouvelle architecture de la RadMon, de nouvelles configurations de polarisation ont été testées pour améliorer la résolution.Deux types de mémoires SRAM avec des nœuds technologiques de 400 et 90 nm ont été testés et calibrés en suivant une méthode de qualification stricte qui comprend des tests protons,dans la plage de 30 à 400 MeV et neutrons, depuis les énergies thermiques jusqu'à des énergies intermédiaires (~ 14 MeV). La mémoire 90 nm améliore la précision et la résolution de la mesure de la fluence hadronique. En outre, l'utilisation simultanée des deux types de mémoires améliore la précision de la détection des neutrons thermiques par rapport à la version précédente, grâce à d'une procédure qui sera détaillée dans ce travail.Les efforts en vue de l'amélioration de la résolution des mesures de TID pour le nouveau RadMon conduisent à la recherche et à l'étude d'un nouveau type de dosimètre : le dosimètre a Grille Flottante (FGDOS). Le capteur intégrant une électronique complexe, une qualification complète sous rayonnement était nécessaire. Des tests en champ mixte, des tests au 60Co et des tests au protons ont été réalisés afin d'évaluer les performances et les problèmes potentiels du capteur. Dans ce contexte, un modèle analytique du capteur a été conçu pour démontrer que la structure à Grille Flottante pouvait être utilisée comme instrument de mesure du ‘charge yield' à température ambiante et sous des champs électriques faibles.La caractérisation de la tolérance au rayonnement du matériel, le processus de qualification et les étalonnages des capteurs ont considérablement amélioré la fiabilité globale et la qualité des mesures sur la nouvelle version du RadMon. Ces améliorations font du RadMon un instrument de référence pour la surveillance des rayonnements des champs mixtes complexes, tels que ceux rencontrés dans le LHC et sa chaîne d'injecteurs, mais aussi pour d'autres centres de recherche en physique des particules, comme JLAB aux États-Unis, J-PARC au Japon

Irradiation Test Results on Cryogenics Electronic Cards using the Smartfusion2 FPGA

In the context of implementing more control and data processing capabilities in new electronic cards at the European Organization for Nuclear Research (CERN), the Smartfusion2 Flash-based Reprogrammable Field Programmable Gate Array (FPGA) has been tested in the CHARM radiation facility at CERN. The CHARM facility was configured to offer a representative radiation environment of the CERN's Large Hardon Collider (LHC) accelerator. The FPGAs were tested during three irradiation campaigns. The observed radiation effects include Single Event Upsets (SEU), Single Event Transients (SET), Single Event Latch-ups (SEL), Single Event Functional Interrupts (SEFI) and failures due to Total Ionizing Radiation (TID). The use of this FPGA is linked to the implementation of appropriate Finite State Machine (FSM) encoding, Printed Circuit Board (PCB) design, and automated power cycling that are here discussed. The suitability of the FPGA in harsh environments and critical applications such as the cryogenics electronics infrastructure in the LHC tunnel is also discussed

General Purpose and Neural Network Approach for Benchmarking Microcontrollers Under Radiation

In this work a testing methodology for micro-controllers exposed to radiation is proposed. General purpose benchmarks are reviewed to provide a mean of testing all the macro-areas of a microcontroller, and a neural network benchmark is introduced as a representative class of novel computing algorithms for IoT devices. Metrics from literature are reviewed and a new metric, the Mean Energy per Unit Workload Between Failure, is introduced. It combines computing performance and energy consumption in a single unit, making it specifically useful to benchmark battery-operated edge nodes. A method to analyse reset causes is also introduced, giving important insights into failure mechanisms and potential patterns. The testing strategy has been validated on a representative class of four Cortex M0+ and Cortex M4 microcontrollers irradiated under a 200MeV proton beam with different fluences. Results from the irradiation campaign are presented and commented on to validate the benchmarks and metrics discussed

Analysis of Bipolar Integrated Circuit Degradation Mechanisms Against Combined TID–DD Effects

Integrated circuits sensitive to both total ionizing dose (TID) and displacement damage (DD) effects can exhibit degradation profiles resulting from a combination of degradation mechanisms induced by both effects. This work presents circuit simulations based on experimental data to explain degradation mechanisms induced by combined TID and DD effects on a bipolar IC current source. First, the effect of the degradation of each internal transistor on the circuit’s response is evaluated by applying electrical parametric changes. Then simulations are performed from different degradation scenarios based on observed circuit behaviors to reproduce the different TID, DD, and combined TID–DD responses. These simulations show that a synergistic interaction between a current leakage induced by DD on a transistor located in the bandgap reference part with the gain degradation of a current mirror induced by both TID and DD appears to be responsible for the combined TID–DD response. It is also shown that the circuit degradation rate depends on the DDD/TID rate ratios encountered during the exposition

Wireless IoT in Particle Accelerators: A Proof of Concept with the IoT Radiation Monitor at CERN

The Internet of Things (IoT) is an ecosystem of web-enabled "smart devices" that integrates sensors and communication hardware to collect, send and act on data acquired from the surrounding environment. Use of the IoT in particle accelerators is not new, with accelerator systems long having been connected to the network to retrieve, send and analyse data. What has been missing is the IoT concept of "smart devices" and above all wireless connectivity. We report here on the advantages of using a particular IoT technology, LoRa, for the deployment of wireless radiation monitors within the CERN particle accelerator complex. IoT Radiation Monitors have been developed as a result of growing demand for radiation measurements where standard infrastructure is not available. As a radiation-tolerant device, the IoT Radiation Monitor is a powerful "eye" for observing the real-time radiation levels in the CERN accelerators. We describe here the technologies used for the project and the various advantages their deployment offers in a particle accelerator environment. This opens up the possibility for the deployment of heterogeneous implementations that would otherwise have been impractical

Proximeter CERN’s detecting device for personnel

he SARS COV 2 virus, the cause of the better known COVID-19 disease, has greatly altered our personal and professional lives. Many people are now expected to work from home but this is not always possible and, in such cases, it is the responsibility of the employer to implement protective measures. One simple such measure is to require that people maintain a distance of 2 metres but this places responsibility on employees and leads to two problems. Firstly, the likelihood that safety distances are not maintained and secondly that someone who becomes infected does not remember with whom they may have been in contact. To address both problems, CERN has developed the “proximeter”, a device that, when worn by employees, detects when they are in close proximity to others. Information about any such close contacts is sent securely over a Low Power Wide Area Network (LPWAN) and stored in a manner that respects confidentiality and privacy requirements. In the event that an employee becomes infected with COVID-19 CERN can thus identify all the possible contacts and so prevent the spread of the virus. We describe here the details of the proximeter device, the LPWAN infrastructure deployed at CERN, the communication mechanisms and the protocols used to respect the confidentiality of personal data

TID, ΦHEH and ΦThN measurements along the SPS accelerator and the adjacent Tunnel Access Areas

In this document, the measurements of Total Ionizing Dose, High Energy Hadron fluence and Thermal Neutron fluence are presented for some areas of the Super Proton Synchrotron, cumulated during 2017 and 2018. The investigation aims at characterizing the radiation field that might affect some sensitive equipment installed by the Beam Instrumentation group (BE/BI). The areas investigated are the arcs and tunnel access areas TA1, TA2 and TA6

SEE cross section calibration and application to quasi-monoenergetic and spallation facilities

We describe an approach to calibrate SEE-based detectors in monoenergetic fields and apply the resulting semi-empiric responses to more general mixed-field cases in which a broad variety of particle species and energy spectra are involved. The calibration of the response functions is based both on experimental proton and neutron data and considerations derived from Monte Carlo simulations using the FLUKA code. The application environments include the quasi-monoenergetic neutrons at RCNP, the atmospheric-like VESUVIO spallation spectrum and the CHARM high-energy accelerator test facility