Upgrades of the RadMon V6 and its Integration on a Nanosatellite for the Analysis and the Comparative Study of the CHARM and Low Earth Orbit Environments

Radiation fields in the CERN accelerator complex are characterized by mixed particles with broad energy ranges. A Radiation Monitoring System, called "RadMon", was developed for the distributed, on-line measurement of the complex radiation fields and their effect on the electronics installed in areas with a harsh radiation environment. The most recent version of the RadMon revealed a critical issue soon after deployment in the tunnel and the experimental areas. Multiple Cell Upsets (MCUs) arising from microlatchup events started showing up on the SRAM-based particle flux sensors equipped by the system, ultimately affecting the measurement and resulting in corrupted data and accuracy losses. A study of the generation of this effect was performed, and a solution using an on-line detection and correction algorithm embedded on an FPGA, was evaluated and implemented on the RadMon device. Furthermore, in the framework of the project CELESTA, a feasibility study was carried out to validate the adaptation of the RadMon to a 1U CubeSat payload. The research was supported by the CERN Knowledge Transfer as a collaboration between the University of Montpellier, the Centre Spatial Universitaire and CERN. Experimental tests were performed at the new CHARM facility, which allows the characterization of small components, as well as large systems, in a mixed-field representative of the Low Earth Orbit. A stand-alone payload module for 1U CubeSats was developed and equipped with sensors of ionizing dose and high energy hadron fluence. In addition a Latchup Experiment was added on the module as part of the scientific goals of the mission. Results of experimental tests led to the definition of a new procedure for the radiation qualification of small satellites at system level. Details of the characterization and the choice of components are presented together with the approach followed. The payload is the first small satellite module ever designed at CERN. It represents the first step of an increasing interest towards radiation qualification at CHARM of electronics for low orbit space missions

Améliorations du RadMON V6 et son intégration dans un nanosatellite pour l’analyse et l’étude comparative des environnements CHARM et LEO

Radiation fields in the CERN accelerator complex are characterized by mixed particles with broad energy ranges. A Radiation Monitoring System, called "RadMon", was developed for the distributed, on-line measurement of the complex radiation fields and their effect on the electronics installed in areas with a harsh radiation environment. The most recent version of the RadMon revealed a critical issue soon after deployment in the tunnel and the experimental areas. Multiple Cell Upsets (MCUs) arising from microlatchup events started showing up on the SRAM-based particle flux sensors equipped by the system, ultimately affecting the measurement and resulting in corrupted data and accuracy losses. A study of the generation of this effect was performed, and a solution using an on-line detection and correction algorithm embedded on an FPGA, was evaluated and implemented on the RadMon device.Furthermore, in the framework of the project CELESTA, a feasibility study was carried out to validate the adaptation of the RadMon to a 1U CubeSat payload. The research was supported by the CERN Knowledge Transfer as a collaboration between the University of Montpellier, the Centre Spatial Universitaire and CERN. Experimental tests were performed at the new CHARM facility, which allows the characterization of small components, as well as large systems, in a mixed-field representative of the Low Earth Orbit.A stand-alone payload module for 1U CubeSats was developed and equipped withsensors of ionizing dose and high energy hadron fluence. In addition a Latchup Experiment was added on the module as part of the scientific goals of the mission. Results of experimental tests led to the definition of a new procedure for the radiation qualification of small satellites at system level. Details of the characterization and the choice of components are presented together with the approach followed.The payload is the first small satellite module ever designed at CERN. It representsthe first step of an increasing interest towards radiation qualification at CHARM of electronics for low orbit space missions.Les champs radiatifs dans le complexe d’accélérateurs du CERN sont caractérisés par des particules mixtes avec un large spectre d’énergie. Le système de surveillance des radiations, le RadMon, a été développé pour la mesure distribuée, et en temps réel, des radiations et ses effets sur l’électronique installée dans les tunnels et les zones expérimentales. Pendant la première phase d’opération du RADMON, un problème critique a été identifié sur les mémoires SRAM utilisées comme capteurs de fluence des hadrons de hautes énergies. Un large nombre de MCU (Multiple Cell Upsets), générés par des microlatchups, ont commencé à apparaître sur les RADMONs, affectant ainsi la précision de mesure de la fluence. Une étude de la cause de cet effet a été réalisée et une solution utilisant un algorithme de détection et de correction en ligne, embarqué sur un FPGA, a été évaluée et mise en place sur les RADMONs installés dans les zones du SPS, PSB, NA62, HiRadMat, ALICE et CHARM.Par ailleurs, dans le cadre du projet CELESTA, une étude de faisabilité a été réalisée pour valider l’adaptation du RadMon à une charge utile pour des applications CubeSat de dimension 1U. Le travail de recherche a été soutenu par le service de transfert de connaissance du CERN en collaboration avec l’Université de Montpellier, le Centre Spatial Universitaire.Les tests expérimentaux ont été effectués dans le nouveau moyen de test CHARM. CHARM offre la possibilité de reproduire les champs radiatifs mixtes présents dans les installations du CERN ainsi que les basses orbites terrestres (LEO).Un module autonome de charge utile pour Cubesat a été développé et équipé avec des capteurs permettant de mesurer dose ionisante ainsi que la fluence des hadrons de haute énergie. Par ailleurs une expérience permettant de détecter des latchups a été ajoutée au module. Les résultats des tests ont permis la définition d’une nouvelle procédure pour la qualification des nano satellites au niveau des radiations sur le système. Ce travail de thèse détaille l’approche suivie pour le choix et la caractérisation des composants utilisés sur la charge utile.La charge utile de CELESTA est le premier projet du CERN sur le sujet de la science des "small satellites". Il représente la première étape d’un intérêt croissant de l’utilisation du moyen de test CHARM pour des missions en environnement spatial

The Consolidation of the CERN Beam Interlock System

The Beam Interlock System (BIS) is a machine protection system that provides essential interlock control throughout the CERN accelerator complex. The current BIS has been in service since 2006; as such, it is approaching the end of its operational lifetime, with most components being obsolete. A second version of the Beam Interlock System, "BIS2", is currently under development and will replace the current system. BIS2 aims to be more flexible by supplying additional on-board diagnostic tools, while also improving the overall safety by adding more redundancy. Crucially, BIS2 increases the number of critical paths that can be interlocked by almost 50%, providing an important flexibility for future additional interlocking requests. BIS2 will come into operation for the LHC in run 4 (2027) and will remain in operation until the end of the planned lifetime of HL-LHC. In this paper, we will focus on the Beam Interlock Controller Manager board (CIBM), which is at the heart of BIS2. Since this module works closely with many other systems that are similar in design to those in BIS1, we will compare how BIS2 improves upon BIS1, and justify the reasons why these changes were made

Simulation of E-Cloud Driven Instability And Its Attenuation Using a Feedback System in the CERN SPS

Electron clouds have been shown to trigger fast growing instabilities on proton beams circulating in the SPS, and a feedback system to control the instabilities is under active development. We present the latest improvements to the Warp-Posinst simulation framework and feedback model, and its application to the self-consistent simulations of two consecutive bunches interacting with an electron cloud in the SPS

Evaluation of an SFP Based Test Loop for a Future Upgrade of the Optical Transmission for CERN’s Beam Interlock System

The Beam Interlock System (BIS) is the backbone of CERN’s machine protection system. The BIS is responsible for relaying the so-called Beam Permit signal, initiating in case of need the controlled removal of the beam by the LHC Beam Dumping System. The Beam Permit is encoded as a specific frequency traveling over a more than 30 km long network of optical fibers all around the LHC ring. The progressive degradation of the optical fibers and the aging of electronics affect the decoding of the Beam Permit, thus potentially resulting in an undesired beam dump event and by this reduce the machine availability. Commercial off-the-shelf SFP transceivers were studied with the aim to improve the performance of the optical transmission of the Beam Permit Network. This paper describes the tests carried out in the LHC accelerator to evaluate the selected SFP transceivers and it reports the results of the test loop reaction time measurements during operation. The use of SFPs to optically transmit safety critical signals is being considered as an interesting option not only for the planned major upgrade of the BIS for the HL-LHC era but also for other protection systems

Interlock System Upgrades at the CERN Accelerator Complex During Long Shutdown 2

The CERN accelerator complex stopped operation at the end of 2018 for the Long Shutdown 2 (LS2), allowing for the LHC Injector Upgrade program (LIU) and consolidation work to be accomplished. A gradual restart of the different accelerators is ongoing in 2021, culminating with the LHC foreseen to be back in operation early 2022. During LS2 a very large range of systems was modified throughout the accelerator complex. This includes the so-called Machine Interlock systems, which are at the heart of the overall machine protection system. This paper gives an overview of the Machine Interlock systems changes during LS2. It includes the installation of a Beam Interlock System (BIS) at the new linear accelerator LINAC4, at the PS-Booster and the installation of a new Injection BIS for the SPS synchrotron. New Safe Machine Parameter flags to protect the SPS transfer line mobile beam dumps against high intensity beams were put in place. The new Warm Magnet Controller (WIC) installations at LINAC4 the PS Booster and the different transfer lines and experimental areas are presented together with the modifications to the Power Interlock Controller protecting the LHC superconducting magnets

E-cloud Driven Single-bunch Instabilities in PS2

One of the proposals under consideration for future upgrades of the LHC injector complex entails the replacement of the PS with the PS2, a longer circumference and higher energy synchrotron, with electron cloud effects representing a potentially serious limitation to the achievement of the upgrade goals. We report on ongoing numerical studies aiming at estimating the e-cloud density threshold for the occurrence of single bunch instabilitie

Reliability studies for CERN’s new safe machine parameter system

The Safe Machine Parameter system (SMP) is a critical part of the machine protection system in CERN’s Large Hadron Collider (LHC) and the Super Proton Synchrotron (SPS). It broadcasts safety-critical parameters like beam energy, beam intensity, the beta functions and flags indicating safety levels of the beam to other machine protection elements. The current SMP will be replaced by a consolidated system during CERN’s Long Shutdown 3, foreseen to start in 2026. In this contribution the results of the reliability study of the new SMP system are presented. This study quantifies the criticality of end-users by identifying the hazard chains leading to potential damage of the involved equipment. Data-driven risk matrices are used to derive acceptable failure frequencies and reliability requirements. The study encompasses Monte Carlo simulations of sub-system level configurations to support the decision-making process in this project

Analysis of SEL on Commercial SRAM Memories and Mixed-Field Characterization of a Latchup Detection Circuit For LEO Space Applications

International audienceA single event latchup (SEL) experiment based on commercial static random access memory (SRAM) memories has recently been proposed in the framework of the European Organization for Nuclear Research (CERN) Latchup Experiment and Student Satellite nanosatellite low Earth orbit (LEO) space mission. SEL characterization of three commercial SRAM memories has been carried out at the Paul Scherrer Institut (PSI) facility, using monoenergetic focused proton beams and different acquisition setups. The best target candidate was selected and a circuit for SEL detection has been proposed and tested at CERN, in the CERN High Energy AcceleRator Mixed-field facility (CHARM). Experimental results were carried out at test locations representative of the LEO environment, thus providing a full characterization of the SRAM cross sections, together with the analysis of the single-event effect and total ionizing dose of the latchup detection circuit in relation to the particle spectra expected during mission. The setups used for SEL monitoring are described, and details of the proposed circuit components and topology are presented. Experimental results obtained both at PSI and at CHARM facilities are discussed

Machine protection experience from beam tests with crab cavity prototypes in the CERN SPS

Crab cavities (CCs) constitute a key component of the High Luminosity LHC (HL-LHC) project. In case of a failure, they can induce significant transverse beam offsets within tens of microseconds, necessitating a fast removal of the circulating beam to avoid damage to accelerator components due to losses from the displaced beam halo. In preparation for the final design to be employed in the LHC, a series of tests were conducted on prototype crab cavities installed in the Super Proton Synchrotron (SPS) at CERN. This paper summarizes the machine protection requirements and observations during the first tests of crab cavities with proton beams in the SPS. In addition, the machine protection implications for future SPS tests and for the use of such equipment in the HL-LHC are discussed