Studying the energy deposition in accelerator components, mechanical supports, services, ancillary equipment and shielding requires a detailed computer readable description of the component geometry. The creation of geometries is a significant bottleneck in producing complete simulation models and reducing the effort required will allow non-experts to simulate the effects of beam losses on realistic accelerators. This paper describes a flexible and easy to use Python package to create geometries usable by either Geant4 (and so BDSIM or G4Beamline) or FLUKA either from scratch or by conversion from common engineering formats, such as STEP or IGES created by industry standard CAD/CAM packages. This paper describes the updates to pyg4ometry since IPAC19. These updates include ROOT geometry loading, refactored geometry processing using CGAL, direct CAD file loading using OpenCASCADE, geometrical feature extraction and geometry comparison algorithms. The paper includes small examples of the new features with explanations.

This work aims to improve the ability of particle accelerator researchers to develop high-performance accelerator cavity designs by creating an overall multiphysics framework that integrates and couples existing application codes. This framework will allow accelerator researchers to build multiphysics models that will optimize cavity design, improve understanding of whole-device performance, and reduce the development and fabrication costs of accelerator research. We utilize the open-source VizSchema data standard as an intermediate data structure interface layer to standardize interfaces between individual application codes. VizScema is extensively documented online, and plugins for VizSchema are available for popular visualization packages, including VisIt and ParaView. Currently, the work focuses on coupling the EM field solver COMSOL and the electron gun code MICHELLE to allow COMSOL field-solve results to be seamlessly used by MICHELLE for particle-solve. Later work will extend this integration to include other fields, particles, and thermodynamics simulation codes.

Fast single-turn injection kicker systems deflect incoming beam onto the orbit of the LHC. The higher intensities of High Luminosity (HL) LHC beams are predicted to cause the ferrite yokes of the LHC injection kicker magnets (MKI), in their current configuration, to heat up to their Curie temperature. Studies to reduce the beam induced heating have been carried out over the past years and resulted in a design featuring a water-cooled RF damper. A significant portion of the beam induced power has been relocated from the yoke to a ferrite in the RF damper. The ferrite damper is cooled via a copper sleeve, brazed to the ferrite, via a set of water pipes. The manufacturing of this RF damper system is challenging since different materials are brazed together to form a complex and fragile assembly, optimized for heat transfer, installed in an ultra-high vacuum environment. This paper outlines fabrication methods and their reproducibility, compares the results of measurements of the thermal interface between the ferrite and copper sleeve, and concludes on the challenges of assuring a production technique that results in a reliable and suitable thermal interface.

The BEam COoler and LAser spectroscopy (BECOLA) is a collinear laser spectroscopy facility at the Facility for Rare Isotope Beams (FRIB) at Michigan State University. Time resolved laser spectroscopy experiments are performed here to study the nuclear structure of radioactive isotopes. The current data acquisition (DAQ) system being used is based on AMD Spartan 6 field programmable gate array (FPGA) and has a time resolution of 8 ns. There was a need to upgrade existing hardware to meet the requirements for higher time resolution of fast ion detectors. A new DAQ system with AMD Zynq System on Chip (SoC) FPGA based time-resolved scaler was designed, developed and fabricated. It achieves a time resolution of 2 ns. The current amplifier-discriminator has an output pulse resolution of 10 ns. To address this constraint and fully leverage the 2 ns time resolution provided by the new SoC FPGA, a new AD with an output pulse resolution of 1 ns was designed. A brief overview of the upgraded DAQ system will be discussed in this paper, including its features, improvements and future updates.

The impact of high-flux protons on the inherent beam loss in the slow extraction from SPS towards the North Area has been recently discussed and potential improvements have been proposed. These solutions are mainly aiming to reduce the high component activation and related reduction of lifetime, as well as observed non straightness in the anode body. Recent studies have allowed to demonstrate feasibility of replacing the currently installed stainless steel tank, flanges, and anode body by lowZ materials. The design iteration and material choice has led to the fabrication of a reduced length prototype, demonstrating mechanical, electrical, as well as the vacuum related performance. The mass reduction of the anode body has been optimized using numerical simulation, considering mechanical and thermal constraints. The paper presents the development of the vacuum vessel, including numerical analysis. The results from the design and prototype tank fabrication will be compared to the existing system. Furthermore, the optimization of the anode body and potential fabrication based on additive manufacturing including 3d optical straightness metrology will be discussed.

The Data Platform is a fully independent system for management and retrieval of heterogeneous, time-series data required for machine learning and general data science applications deployed at large particle accelerator facilities. It is an independent subsystem within the larger Machine Learning Data Platform (MLDP) which provides full-stack support for such facilities and applications [1]. The Data Platform maintains the heterogeneous data archive along with all associated metadata and post-acquisition user annotations. It also facilitates all interactions between data scientists and the data archive, thus it directly supports all back-end data science use cases. Accelerator facilities include thousands of data sources sampled at high frequencies, so ingestion performance is a key requirement and the current challenge. We describe the operation, architecture, performance, and development status of the Data Platform.

The Radio Frequency System-on-Chip (RFSoC) FPGA-based high-performance bunch-by-bunch beam position monitor (BxB BPM) was developed and commissioned at NSLS-II. The new BxB BPM features a 14-bit 5 Gsps ADC, directly sampling 2 ns four-button signals, and digital signal processing with a synchronized 500 MHz RF reference clock. The BxB BPM provides 32 K points of ADC raw data, 5 K turns for up to 1320 bunch amplitude and position data, 2.6 million turn-by-turn (TxT) data points, 10 K turns of circular buffer, and 10 Hz streaming data. The potential applications include, but are not limited to measuring injection transient, efficiency, ion instability detection, and single/multi-bunch motion analysis. A ~15 μm single-bunch resolution was confirmed with the beam test. This paper will present the beam test results, hardware FPGA firmware architecture, and control system interface for operation.

The beam coupling impedance is a key design parameter for all accelerator structures. Recently, we have introduced a novel simulation approach for impedance calculations in 3D-geometry. Unlike conventional methods, this approach is based on the solution of Maxwell’s equations in the frequency domain using a high-order finite element technique. The main challenge for all impedance simulations, however, is the huge amount of computational resources that is required for the numerical discretization of electromagnetically large accelerator structures. In this contribution, we introduce a specialized domain decomposition technique for impedance simulations. The technique allows to handle large accelerator structures by decomposing the computational domain into subdomains that interact by means of suitably chosen boundary conditions. We describe a class of such boundary conditions that accurately take into account the modal wave contributions traveling through domain interfaces in the presence of a particle beam. An application of the method considered in the paper is the full impedance characterization of a large in-vacuum undulator for the PETRA IV synchrotron source.

The elliptically polarized undulator with a period length of 56 mm, called EPU56, is part of the Taiwan Photon Source (TPS) phase-III beamline project. Its control system is built within the EPICS framework using motion controllers and EtherCAT. The control systems of EPU56 include a safety interlock system, which automatically stops movement based on limit switches, torque limit switches,emergency stop button, and readings from the enclosed linear optical encoder. In addition, the control system offers settings for adjusting the correction magnets' power supply and employs optical absolute encoder motors to control the movement of the Gap and Phase. In order to maintain stability during movement, PID control is applied to the motion process by the motion controller. To further enhance precision, the system also employs an integrator limit within the motion controller for additional adjustments. This paper describes the development of the control system and the enhancements made to the insertion device movement process.

The Beam Interlock System (BIS) is the backbone of the machine protection system throughout the accelerator complex at CERN, from LINAC4 to the LHC. After 15 years of flawless operation, a new version of the BIS is currently being produced and will be installed in the LHC, SPS and North Area during CERN’s Long Shutdown 3, planned to start in 2026. Overall, more than 3,000 Printed Circuit Boards will be produced and assembled outside CERN. In addition, more than 120,000 lines of firmware and supporting scripts are written to implement the critical and monitoring functionalities of the BIS. Both hardware and firmware need to be thoroughly tested before installation and operation to guarantee the high levels of reliability and availability required by the operation of the accelerators. In this paper we present the testing methodology including the development of dedicated testbeds for hardware validation, the use of comprehensive simulation and continuous integration for firmware development, and the implementation of automated tests for system-level functional validation.

The Safe Machine Parameter (SMP) system is an electronic hardware-based system which has been an integral part of the LHC’s machine protection strategy since it started operation. Its primary objective is to provide several parameters and interlock signals to critical machine protection users across the LHC and SPS accelerators, whilst prioritizing high reliability and availability. After almost two decades of operation, there is a need to upgrade the SMP hardware electronics. In the High Luminosity LHC era the requirements of connected systems have changed, leading to new system functions and operational requirements which must be integrated into the new design. This paper details the electronic design considerations of developing the second-generation SMP. The general distribution of parameters relies on the CERN WhiteRabbit timing network renovation, for which dedicated high-precision clock components were selected and tested on a prototype board. Details of the hardware design and validation are discussed, along with the comprehensive upgrades aimed at delivering an SMP system with expanded monitoring and diagnostic features.

The recent development of advanced black box optimization algorithms has promised order of magnitude improvements in optimization speed when solving accelerator physics problems. These algorithms have been implemented in the python package Xopt, which has been used to solve online and offline accelerator optimization problems at a wide number of facilities, including at SLAC, Argonne, BNL, DESY, ESRF, and others. In this work, we describe updates to the Xopt framework that expand its capabilities and improves optimization performance in solving online optimization problems. We also discuss how Xopt has been incorporated into the Badger graphical user interface that allows easy access to these advanced control algorithms in the accelerator control room. Finally, we describe how to integrate machine learning based surrogate models provided by the LUME-model package into online optimization via Xopt.

The thermal diffusion and acoustic properties of Nb impacts the thermal management of devices incorporating Nb thin films such as superconducting radiofrequency (SRF) cavities and superconducting high-speed electronic devices. The diffusion and acoustic properties of 200-800 nm thick Nb films deposited on Cu substrates were investigated using time-domain thermoreflectance (TDTR). The films were examined by X-ray diffraction, scanning electron microscopy, and atomic force microscopy. The grain size and thermal diffusivity increase with film thickness. The thermal diffusivity increased from 0.100± 0.002 cm2s-1 to 0.237± 0.002 cm2s-1 with the increase in film thickness from 200 nm (grain size 20±6 nm) to 800 nm (grain size 65±16 nm). Damped periodic photoacoustic signals are detected due to laser heating generated stress in the Nb film, which results in an acoustic pulse bouncing from the Nb/Cu and the Nb/vacuum interfaces. The period of the acoustic oscillation gives a longitudinal sound velocity of 3637.3 ms-1 inside the Nb films, which is in good agreement with the values reported in the literature.

The APS Upgrade (APS-U) multi-bend acromat storage ring requires 1000 high-stability unipolar magnet power supplies. A precision current measurement and calibration system has been developed to independently measure the power supply output current to ensure the accuracy and repeatability of the supplies. The measurement system uses custom commercial DCCT current transducers along with APS-U-designed electronics. The calibration system is designed to perform on-demand calibration of all 1000 DC measurement channels simultaneously using a single current reference source instrument. The calibration system includes a precision current multiplier and impedance buffer based on a novel use of DCCT technology that provides a local precision calibration current for up to 6 DCCTs in series through multi-turn low impedance calibration windings. All system components have been received and passed acceptance testing; the full system is currently being installed in the new storage ring and full-scale evaluation will begin in early 2024. This paper describes the system design and presents preliminary test results.

In this paper, the focus is on the development of a bipolar high-current correction magnet power supply for the future TPS-II permanent magnet corrector coil. The maximum output current of the prototype is speci-fied as 20 A, operating at a voltage of 48 V. This con-figuration enhances the amplitude of the trim magnetic core correction magnetic field, thereby providing greater flexibility in manufacturing the permanent magnet corrector coil. The Danisense DP50-IP-B DCCT is the current feedback component to design a power supply with high current and stability. MOSFETs are configured in a full bridge setup serving as power switches. The driving frequency is set at 40 kHz. Analogue modulation control circuitry and pro-tection circuits ensure precise current control loop modulation. Finally, a hardware prototype circuit is constructed in the power supply laboratory with an input voltage of 48 V, an output current of 20 A, a maximum power of 960 W, and the current ripple com-ponent maintained within 400 μA. This validates the control loop design of the prototype, demonstrating the capability to achieve rapid and stable output cur-rent performance. The small-signal bandwidth tested using a 1V input reference signal shows a -3 dB band-width of 8.51 kHz. Long-term current stability is with-in ±10 ppm, and the interface is compatible with exist-ing TPS correction magnet power supply interfaces, allowing for direct operation within the current sys-tem.

Tantalum has been used as cladding material for water-cooled solid tungsten targets at many leading spallation neutron production facilities thanks to its high neutron yield, manageable radiation damage behavior, and excellent corrosion/erosion resistance in radiation environments. However, from a safety hazard perspective, thermal neutron capture of tantalum in spallation environments causes a high specific decay heat in the target volume, which often becomes a limiting factor in increasing the beam power on the target. In this paper, we studied vacuum hot pressing (VHP) parameters to diffusion bond zirconium to tungsten to explore the feasibility of using zirconium alloys as an alternative cladding material to tantalum. Zirconium alloys have long been used as cladding material for early generation solid spallation targets, and nuclear fuel rods. In spallation environments zirconium has significantly lower decay heat with shorter decay time compared to tantalum. The hot isostatic pressing (HIP) of zirconium and tungsten is known to produce limited bonding quality due to the formation of the brittle ZrW2 intermetallic layer. To overcome this problem, placing a vanadium interlayer between tungsten and zirconium has been proposed by exploring parameter space in binary alloy phase diagrams. Under the VHP conditions, 860 ◦C at 70 MPa for 4 hours, Zr-V and V-W showed good diffusion bonding, which demonstrates the feasibility of a single step HIP process to make the zirconium alloy clad tungsten spallation volumes.