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The European Spallation Source (ESS), Sweden, currently in its early operation phase, aims to be the most powerful neutron source in the world. Proton beam pulses are accelerated and sent to a rotating tungsten target, where neutrons are generated via the spallation effect. The damage potential of the ESS proton beam is high and melting of copper or steel can happen within less than 5 microseconds. Therefore, highly reliable and fast machine protection (MP) systems have been designed and deployed. The core system of ESS Machine Protection is the Fast Beam Interlock System (FBIS), based on FPGA technology. FBIS collects data from all relevant accelerator and target systems through 300 direct inputs and decides whether beam operation can start or must stop. The architecture is based on two main building blocks: Decision Logic Node (DLN), executing the protection logic and realizing interfaces to Higher-Level Safety, Timing System and EPICS Control System. The second block, the Signal Condition Unit (SCU), implements the interface between FBIS inputs/outputs and DLNs. This paper gives an overview on FBIS and a summary on its performance during beam commissioning phases since 2021., Proceedings of the 31st International Linear Accelerator Conference, LINAC2022, Liverpool, UK

The European Spallation Source (ESS ERIC), based in Lund (Sweden), will be in a few years the most powerful neutron source in Europe with an average beam power of 5 MW. It will accelerate proton beam pulses to a Tungsten wheel to generate neutrons by the spallation effect. For such beam, the Machine Protection System (MPS) at ESS must be fast and reliable, and for this reason a Fast Beam Interlock System (FBIS) based on FPGAs is required. Some protection functions monitoring slow values (like temperature, mechanical movements, magnetic fields) need however less strict reaction times and are managed by PLCs. The communications protocol established between PLCs and FBIS is PROFINET fieldbus based. The Anybus CompactCom allows an host to have connectivity to industrial networks as PROFINET. In this context, FBIS represents the host and the application code to interface the AnyBus CompactCom has been fully developed in VHDL. This paper describes an open source implementation to interface a CompactCom M40 with an FPGA., Proceedings of the 18th International Conference on Accelerator and Large Experimental Physics Control Systems, ICALEPCS2021, Shanghai, China

The European Spallation Source, currently under construction in Lund Sweden, will be a spallation neutron source driven by a superconducting proton linac with a design power of 5 MW. The linac features a high peak current of 62.5 mA and long pulse length of 2.86 ms with a repetition rate of 14 Hz. The normal conducting part of the linac has been undergoing beam commissioning in multiple steps, and the main focus of the beam commissioning has been on bringing systems into operation, including auxiliary ones. In 2022, beam was transported to the end of the first tank of the five-tank drift tube linac. This paper provides a summary of the beam commissioning activities at ESS and the current status of the linac., Proceedings of the 31st International Linear Accelerator Conference, LINAC2022, Liverpool, UK

The construction of the ESS accelerator is in full swing. Many key components have been delivered from our in-kind partners and installation, testing and commissioning is making remarkable progress. The first machine section to be commissioned with beam is the Normal Conducting Linac (NCL). When completed, a 14 Hz, 2.86 ms proton beam up to 62.5 mA will be transported from the Ion Source, through the Low Energy Beam Transport (LEBT) line, the Radiofrequency Quadrupole (RFQ), the Medium Energy Beam Transport (MEBT) line and the five Drift Tube Linac (DTL) tanks up to 90 MeV where it will be injected in the first superconducting module of the machine. This paper will highlight recent progress across the NCL, present briefly the first commissioning results and discuss the upcoming phases as well as challenges in delivering a machine capable of meeting the requirements for a next generation spallation neutron facility., Proceedings of the 13th International Particle Accelerator Conference, IPAC2022, Bangkok, Thailand

The new control system for Radio Frequency (RF) structures at Legnaro National Laboratories (LNL) is presented in this document. LNL is one of the four national laboratories of the National Institute for Nucler Physics (INFN) and it is devoted to basic research in nuclear physics and nuclear-astrophysics, together with applications of nuclear technologies. The subject of this Ph.D. thesis is indeed the development of a fully digital RF feedback system, focusing on the validation of the RF controller, its programming and its integration in the particle accelerator control system. The RF controller interacts directly with the cavities and it works in a real-time closed loop. It is a set of analog and digital electronics which provides phase, amplitude and frequency corrections to stabilize the RF field in presence of disturbances and vibrations due to other subsystems of the accelerator. The control algorithm is implemented via a programmable device as an FPGA. This increases dramatically the flexibility and the programmability of the controller. The digital board of the RF controller can work in a wide range of the RF spectrum. It is a versatile tool, easy to adapt to 40/80/160/352 MHz resonators, thus spanning all types of cavities of the final SPES configuration. At LNL, it may be used to control RF cavities like bunchers to pulse the beam, superconducting cavities to accelerate the beam and RF quadrupoles (RFQ) to both accelerate and focus the beam. Most of them work in superconducting condition, while the other ones in normal condition. The controlling and the monitoring of the RF controller is done by the particle accelerator control system based on EPICS (Experimental Physics and Industrial Control System). It is a widely adopted software framework for control systems. EPICS is a set of tools, libraries and applications developed collaboratively and used worldwide to create distributed soft real-time control systems for scientific instruments such as particle accelerators. Beam transport was carried out with the 8 cavities working in superconducting mode with the new instruments. The controller kept locked the cavities for few days. In this time the controller has proven to be more stable and reliable than the precedent system. The first chapter of the document introduces the SPES and ALPI facility and the RF subsystem to a certain level of details: RF acceleration concepts and Low Level RF (LLRF) control for an optimum energy gain of the particle beam. In order to better understand the issues faced during the design of the control system it is useful to derive mathematical models of the RF cavities. This is the subject of the second chapter. In the third chapter the disturbance sources of the accelerating field are listed, besides clarifying the stability requirements, the frequency tuning of the cavities and their driving modes. Furthermore, the choice of the frequency sampling is outlined. The fourth chapter introduces the controller in detail. The boards functionalities are highlighted, the fundamental elements of the boards are described as well as the communication between components and boards. The fifth, sixth and seventh chapters describe the main contribution of this Ph.D. thesis. The firmware development for the Field Programmable Field Array, that is the heart of the RF controller, is covered in chapter five, emphasizing the module for the communication with the accelerator control system and the module that implements the control algorithms. The sixth chapter gives an overview of the EPICS framework, focusing on the driver support, the integration of the RF controller with the EPICS based control system is further expanded while in the last section the RF cavity tuning is explained. The seventh chapter is split in two sections. The first section lists the tests performed in order to qualify the boards of the RF controller. The second section analyzes some key parameters acquired during a successful beam test in real working conditions, where the performance of the new controller has been evaluated. Finally, a concluding chapter summarizes the results obtained so far and outlines improvements and future upgrades that can implement new functionalities in the Radio Frequency control system.

For the SPES project at Legnaro National Laboratories (LNL), a Low-Level Radio Frequency (LLRF) has been designed to have flexibility, reusability and an high precision. It is an FPGA-based digital feedback control system using RF ADCs for the direct undersampling and it can control at the same time eight different cavities. The LLRF system was tested on the field with an accelerated beam. In the last year some improvements on the firmware, software and hardware of the control system have been done. In this paper the results carried out in the more recent tests, the future works and the upgrades of the system will be detailed., Proceedings of the 16th Int. Conf. on Accelerator and Large Experimental Control Systems, ICALEPCS2017, Barcelona, Spain

SPES (Selective Production of Exotic Species) is an ISOL type facility for production and post-acceleration of exotic nuclei for forefront research in nuclear physics. Radioactive (RA) species (A=80/160) will be produced by fissions induced by a proton beam impinging on an UCx target: the proton beam will be delivered by a com-mercial cyclotron with a 40 MeV maximum energy and a 0.25 mA maximum current. The RA species, extracted from the Target-Ion-Source system as a 1+ beam , will be cooled in a RFQ (radiofrequency quadrupole) beam cool-er (RFQ-BC) and purified from the isobars contaminants through a High Resolution Mass Separator (HRMS). Post-acceleration will be performed via an ECR-based charge breeder, delivering the obtained q+ RA beam to a being built CW RFQ and to the being upgraded superconducting (sc) linac ALPI (up to 10 MeV/A for a mass-to-charge ratio A/q=7)., Proceedings of the 9th Int. Particle Accelerator Conf., IPAC2018, Vancouver, BC, Canada

The ALPI linac at INFN-LNL was substantially refur-bished in 2018, especially in view of its use as secondary accelerator for exotic species in the framework of the SPES project. In particular: 10 magnetic triplets were replaced with higher gradient ones; two cryomodules with quarter wave resonator were moved from the PIAVE injector to ALPI, so as to make them available both for exotic and stable beams; the cryogenic plant was renovat-ed; the whole linac, its injector and its beam lines were eventually realigned via LASER tracking (LT). The ex-pected outcome of the refurbishment project is a larger beam transmission (crucial for the efficient transport of the unavoidably low current exotic beams) and improved overall reliability so as to further extend the lifetime of an already 25 years old machine. The hardware commission-ing of this new configuration will be reported., Proceedings of the 10th Int. Particle Accelerator Conf., IPAC2019, Melbourne, Australia

The new Low-Level Radio Frequency (LLRF) control system for linear accelerator at Legnaro National Laboratories (LNL) of INFN is presently being commissioned. A digital Radio Frequency (RF) controller was implemented. Its goal is to stabilize the amplitude, the phase and the frequency of the superconducting cavities of the Linac. The resonance frequency of the low beta cavities is 80 MHz, while medium and high beta cavities resonate at 160 MHz. Each RF controller controls at the same time eight different cavities. The hardware complexity of the RF controller (RF IOC) is reduced by adopting direct RF sampling and the RF to baseband conversion method. The main hardware components are RF ADCs for the direct undersampling of the signals picked up from cavities, a Xilinx Kintek 7 FPGA for the signal processing and DACs for driving the power amplifiers and hence the cavities. In the RF IOC the serial communication between FPGA and ADCs and between FPGA and DACs is based on JESD204b standard. An RF front-end board (RFFE) is placed between cavities and the RF IOC. This is used to adapt the power level of the RF signal from the cavities to the ADCs and from the DACs to the power amplifiers. This paper addresses the LLRF control system focusing on the hardware design of the RF IOC and RFFE boards and on the first test results carried out with the new controller., Proceedings of the 28th Linear Accelerator Conf., LINAC2016, East Lansing, MI, USA

The Computer-on-Module approach makes cutting edge technology easily accessible and lowers the entry barriers to anyone prototyping and developing embedded systems. Furthermore, it is possible to add all the system specific functionalities to the generic PC functions which are readily available in an off-the-shelf core module reducing the time to market and enhancing the creativity of system engineers. The purpose of this paper is to show a custom hardware platform based on the tiny and low power Intel Edison Compute Module, which uses a 22nm Intel processing core and contains connectivity elements to ensure device-to-device and device-to-cloud connectivity. The Intel Edison carrier board designed is expected to act as a local intelligent node, a readily available custom EPICS*,** IOC for extending the control reach to small appliances in the context of the SPES project. The board acts as an Ethernet to RS232/RS422 interface translator with Power-Over-Ethernet supply and network booting as key features of this platform. The x86 architecture of the Edison makes standard Linux software deployment straightforward. Currently the board is in prototyping stage., Proceedings of the 15th Int. Conf. on Accelerator and Large Experimental Physics Control Systems, ICALEPCS2015, Melbourne, Australia

The ADIGE (Acceleratore Di Ioni a Grande carica Esotici) injector of the SPES (Selective Production of Exotic Species) project is now in an advanced phase of installation. Its main components have been designed following particular needs of the project: first, an Electron Cyclotron Resonance (ECR)-based Charge Breeder (SPES-CB), to boost the charge states of the radioactive ions produced at SPES and allow their post-acceleration. Then, a stable 1+ source and a complete electrostatic beam line to characterize the SPES-CB. Finally, a unique Medium Resolution Mass Spectrometer (MRMS, R=1/1000), mounted on a high voltage platform downstream the SPES-CB, to clean the radioactive beam from the contaminants induced by the breeding stage. This contribution describes the status of the injector, in particular the installation of the platform housing the MRMS, the access and safety system adopted and the first beams to be extracted from the stable 1+ source., Proceedings of the 10th Int. Particle Accelerator Conf., IPAC2019, Melbourne, Australia