Accelerator-driven high brilliance neutron sources are an attractive alternative to the classical neutron sources of fission reactors and spallation sources to provide scientists with neutrons. A new class of such neutron facilities has been established referred to as High-Current Accelerator-driven Neutron Sources (HiCANS). The basic features of HiCANS are a medium-energy proton accelerator with of tens of MeV and up to 100 mA beam current, a compact neutron production and moderator unit and an optimized neutron transport system to provide a full suite of high performance, fast, epithermal, thermal and cold neutron instruments. The Jülich Centre for Neutron Science (JCNS) has established a project to develop, design and demonstrate such a novel accelerator-driven facility termed High Brilliance neutron Source (HBS). The aim of the project is to build a versatile neutron source as a user facility. Embedded in an international collaboration, the HBS project offers the best flexible solutions for scientific and industrial users. The overall conceptual and technical design of the HBS as a blueprint for the HiCANS facility has been published in a series of recent reports. The status and next steps of the project will be presented, focusing on the high-current linear accelerator and the proton beamline, including a novel multiplexer to distribute the proton beam to three different neutron target stations while adapting a flexible pulse structure.

Capable of achieving a high repetition rate with strong focusing, Fixed Field Alternating gradient (FFA) accelerators have the potential to be used for pulsed high intensity operations. With no pulsed high intensity FFA ever built so far, a prototype machine called FETS-FFA has been proposed to study the FFA option for the next generation spallation neutron source (ISIS-II). One of the essential components of this machine will be the main magnets which must satisfy the following conditions: zero chromaticity during acceleration, flexibility in operating tune point to test dynamics for high beam intensity and a large dynamic aperture to avoid uncontrolled loss. The chosen lattice design utilizes spiral magnets to provide edge focusing to focus in the vertical direction while also introducing a reverse bending magnet to better control the vertical tune. A three-dimensional study is being carried out in OPERA 3D software to investigate the parameters of the magnets to achieve the required field. The details on the design will be presented in this paper.

A liquid lithium target system is being developed for laser ion sources. Existing laser ion sources are operated at the repetition rate of the order of 1 Hz. The limitation stems from the use of solid laser targets because of the craters created and the need to provide a fresh surface by either repositioning the laser beam or the target. In addition, an enormously large surface area is needed for long-term operation. This limits the total yield of lithium ions and the application of laser ion sources. To dramatically increase the repetition rate, we propose the use of a liquid lithium target in a crucible because a liquid surface shape is recovered by itself after laser irradiation. The establishment of a liquid target system is an important objective for the development of the intense lithium beam driver for a clean compact source of a directional neutron beam. In the conference, the concept and design of experimental apparatus for the development will be presented.

Many reactor-based neutron sources are planned to shut down in the near future, and this is despite the increasing demand for neutron beamlines for a wide range of scientific and industrial applications. Consequently, compact accelerator-based neutron sources arise as a competitive alternative that could meet the need for medium-flux fission or spallation sources. In this work, we explore the performance of compact electron accelerators as neutron drivers and propose a preliminary target design for an X-band electron-linac-based neutron source.

Ongoing studies at the Spallation Neutron Source (SNS) Beam Test Facility (BTF) seek to understand and model bunch dynamics in a high-power LINAC front-end. The BTF has recently been upgraded with a reconfiguration from a U-shaped line to a Straight line. We report the current state of model benchmarking, with a focus on RMS beam sizes within the FODO line. The beam measurement is obtained via three camera/screen pairs in the FODO line. This presentation discusses the methodology and results of this measurement.

A novel deuteron accelerator concept, the deuteron cyclotron auto-resonance accelerator (dCARA) is presented here, with (a) an analytical theory to characterize a simplified model for dCARA, (b) simulated tracks of deuteron orbits in a more realistic model for dCARA, and (c) CST-Studio particle-in-cell simulations for high-current deuteron beams in a realistic dCARA. These predict that dCARA will produce a high-current multi-MeV beam of accelerated deuterons along an axis parallel to, but displaced from, the center conductor of a coaxial resonator immersed in a uniform static magnetic field. The example presented, where the magnetic field strength is 7.0 T (for cyclotron auto-resonance at 53.0 MHz), acceleration of a 100 mA deuteron beam from 60 keV to 35 MeV is predicted to occur along a 2.8 m long half-wave resonant cavity, with an efficiency of 88%. Such a beam could be highly competitive with that produced either with linacs or cyclotrons for an application to produce, via deuteron stripping, a high flux of neutrons with an energy spectrum centered near 14.1 MeV, as needed for testing inner-wall materials for a future deuterium-tritium fusion power reactor.

IFMIF-DONES is an ESFRI facility based on a 5 MW deuteron accelerator currently under construction in Granada (Spain) as part of the European roadmap to fusion electricity. Its main goal is to characterize and qualify materials under a neutron field with an induced damage like the one faced in a fusion reactor, developing a material database for the future fusion nuclear reactors. Moreover, a list of medium neutron flux experiments in other irradiation areas for fusion and non-fusion applications have been identified previously and are under analysis. The construction phase was officially launched from March 2023, after setting up the steering committee for the DONES Program composed of several countries. To support the preparation of the key documentation and consolidate contributions from parties, a set of tasks is being developed within the framework of the new DONES Consolidation Phase project (DONES-ConP1). In this contribution, the main objectives of the project such as the drafting of the acceptance tests for the procurement, the first version of the irradiation plan for fusion and non-fusion applications, or the update of key project documentation will be discussed.

An 820 mA CW positive ion source is being developed to produce Mo-99 using the fusion of deuterium and tritium ion beams on a rotating target to produce neutrons for use in the production of radiopharmaceuticals. The ion source consists of an RF plasma source, a multi-aperture extractor, and 300 kV accelerating column. This paper will describe a simulation study of the beam through the extractor grid and the accelerator to the target. The uniformity of beam distribution on the target is an important aspect of the simulation.

The Proton Power Upgrade project at the Spallation Neutron Source at Oak Ridge National Laboratory will increase the proton beam power capability from 1.4 to 2.8 MW. Upon completion in early 2025, 2 MW of beam power will be available for neutron production at the existing first target station (FTS) with the remaining beam power available for the future second target station (STS). The project has installed seven superconducting radio-frequency (RF) cryomodules and supporting RF power systems to increase the beam energy by 30% to 1.3 GeV, and the beam current will be increased by 50%. The injection and extraction region of the accumulator ring are being upgraded, and a new 2 MW mercury target has been developed along with supporting equipment for high-flow gas injection to mitigate cavitation and fatigue stress. The first four cryomodules and supporting systems were commissioned in 2022-2023 and supported neutron production at 1.05 GeV, 1.7 MW with high reliability. The first-article 2 MW target was operated successfully for approximately 4400 MW-Hours over two run periods. The long outage began in August 2023 for installation of the remaining technical equipment and construction of the Ring-to-Target Beam Transport tunnel stub that will enable connection to the STS without interrupting operation of the FTS. The upgrade is proceeding on-schedule and on-budget, and resumption of neutron production for the user program is planned for July 2024.

A pulsed muon beam has been generated by a 3-GeV 333-microA proton beam on a muon target made of graphite at J-PARC, Materials and Life Science Experimental Facility. The first muon beam was successfully generated in 2008, and 300-kW proton beam has been operated by a fixed target till 2014. To extend the lifetime, a muon rotating target, in which the radiation damage is distributed to a wider area, had been developed. The muon rotating target #1 was installed in 2014 and had operated for five years until 2019. The rotating target #2 has stably operated at 830 kW until now in 2023. 1-MW operation was also completed for 32hours in 2020. Simultaneously, in the COMET experiment to explore the muon-electron conversion process, 8 GeV proton beam with an intensity of 3.2 kW in Phase 1 and 56 kW in Phase 2 will irradiate targets in a superconducting solenoid magnet. The MLF 2nd target station is a future project where 3 GeV protons will irradiate a tungsten target to produce high-brightness neutrons and muons. In this presentation, the status and future prospect of the muon target at J-PARC MLF MUSE, the COMET target, and MLF 2nd target station will be introduced.

The core components of the LANSCE accelerator complex – the beam source area, drift-tube and cavity-coupled linear accelerators – are more than 50 years old; a critical subsystem for beam delivery to the Lujan Center, the proton storage ring (PSR), is more than 20 years old. The proposed LAMP project is intended to begin a revitalization and update of the LANSCE accelerator complex, starting with the beam source region, drift-tube linac, and PSR. To help assure we have selected an optimal candidate design for the source region, an internal workshop was held in August 2023 to consider options for providing two beam species at the peak and average currents, and beam macropulse formats, required by the various LANSCE user stations. This document describes the workshop goals and processes, presents the various configurations considered, and lists the results of the downselect process and potential paths forward.

The study investigates the radiation attenuation performance of five ternary glass systems with varying chemical compositions: 50P2O5-(50-x)BaO-xEu2O3, where x = 0, 1, 2, 4, and 6 mol%. It utilizes theoretical and Monte Carlo methods to determine shielding parameters such as attenuation coefficients, mean free path, value layers, electron densities, conductivity and neutron removal cross-sections across an energy range from 1 keV to 100 GeV. In addition to these analyses, the study explores kinetic energy stopping potentials and projected ranges of ions (H+, He+, and C+) through the Stopping and Range of Ions in Matter database. Furthermore, research evaluates the dose rate attenuation behaviour and trajectories of photons bombarded from 137Cs and 60Co sources using Particle and Heavy Ion Transport code System. Obtained results show that sample: 50P2O5-44BaO-6Eu2O3 with higher Eu3+-doped glass has a potential for radiation shielding application among selected samples and is comparable with previously recommended, tested polymer and glass samples.

ESS elliptical cryomodules, CEA-INFN-STFC in-kind contribution, undergo site acceptance test at ESS Lund Test Stand (TS2). Here the Field Emission operation experience, modules performances statistics and limiting mechanism, diagnostics equipment and analysis tool are described. High energy field emission and dose rate operational challenges and long-term superconducting LINAC operational strategy are described.

The ISIS-II Neutron and Muon source is the proposed next generation of, and successor to, the ISIS Neutron and Muon Source based at the Rutherford Appleton Laboratory in the United Kingdom. Anticipated to start construction in 2031, the ISIS-II project presents a unique opportunity to incorporate environmental sustainability practices from its inception. A Life Cycle Assessment (LCA) will examine the environmental impacts associated with each of the ISIS-II design options across the stages of the ISIS-II lifecycle, encompassing construction, operation, and eventual decommissioning. This proactive approach will assess all potential areas of environmental impact and seek to identify strategies for minimizing and mitigating negative impacts, wherever feasible. This presentation will provide insights into the process and first results of the LCA of the entirety of the ISIS-II project.

We propose and demonstrate a time-resolved, two-dimensional temperature monitoring technique for nanocrystalline diamond stripper foils exposed to high-intensity hydrogen ion (H-) beams at the Spallation Neutron Source (SNS) accumulator ring which is independent of foil emissivity. The technique utilizes a two-color imaging pyrometer in the shortwave infrared (SWIR) spectral band to measure thermal radiation from stripper foils located 40 meters away from the measurement site. This work presents a unique optical design, optical calibration of the system using a high-temperature blackbody source, preliminary temperature measurement results from two stripper foils (new and used) under various H‒ production beam conditions with average powers up to 1.7 MW and energy of 1.0 GeV. This technique can be utilized to understand the thermal behavior of charge strippers under high-intensity particle beams, providing crucial feedback to operations to control foil temperature and ensure foil lifetime.

The Los Alamos Neutron Science Center (LANSCE) accelerator produces high intensity H+ and H- beams for multiple experiments in fundamental and national security science. The proposed LANSCE Modernization Project (LAMP) is evaluating necessary upgrades to enable continuous LANSCE operations in years to come. LAMP seeks to upgrade the H+ and H- 750 kV Cockcroft-Walton (CW) generators with a dual-beam, 3-MeV Radiofrequency Quadrupole (RFQ). For technology maturation and know-how associated with this concept, an RFQ test stand with LAMP-like layout is being set-up to demonstrate dual-beam operation in an RFQ with all beam patterns required by experiments. The RFQ test stand will have 35-keV H+ and H- beamlines that simultaneously inject into a 750 keV RFQ. Assembly and initial characterization of the H+ beam is under way. The H- beamline has stringent requirements and will also demonstrate systems like a beam chopper and a low frequency buncher to produce required beam patterns. We describe the design of the H- beamline based on accelerator codes Warp and Impact.

Radiation in the injection section of a synchrotron radiation facility is primarily the result of injection beam loss, which occurs each time the current is replenished, and storage beam loss, which accounts for the lifetime during routine operations. This study conducted neutron measurements by using high-sensitivity neutron detectors and obtained the total electron loss during the unfolding process. With the known lifetime, the ratio of injection beam loss to storage beam loss and the total loss in the injection section of the Taiwan Photon Source facility during routine operations were determined. The total electron loss at the measurement site was approximately five millionths of the full load current. The ratio of injection beam loss to storage beam loss was 1.64. The total electron loss was 0.44 pC, with 0.27 pC being attributed to injection beam loss and 0.17 pC being attributed to storage beam loss.

Neutron scattering experiments have undergone significant technological development through large area detectors with concurrent enhancements in neutron transport and electronic functionality. Data collected for neutron events include detector pixel location in 3D, time and associated metadata, such as sample orientation and environmental conditions. Working with single-crystal diffraction data we are developing both interactive and automated 3D analysis of neutron data by leveraging NVIDIA’s Omniverse technology. We have implemented machine learning techniques to automatically identify Bragg peaks and separate them from diffuse backgrounds and analyze the crystalline lattice parameters for further analysis. A novel CNN architecture has been developed to identify anomalous background from detector instrumentation for dynamical cleaning of measurements. Our approach allows scientists to visualize and analyze data in real-time from a conventional browser, which promises to improve experimental operations and enable new science. We have deployed a cloud based server, leveraging Sirepo technology, to make these capabilities available to beamline users in the control room.

The institute of applied physics (IAP), university of Frankfurt, has been working for years on the development of increasingly powerful 4-Rod RFQ accelerators for hadron acceleration. The need for such accelerators has increased significantly in the recent past, as accelerator-driven neutron sources are becoming increasingly important following the closure of various test reactors. High beam currents, particle energies and operational stability are often required from those LINACs. In order to meet these requirements, the copper structure of the RFQ is to be manufactured using a new type of pure copper 3D printing in order to be able to introduce optimized cooling channels inside the copper parts. Comprehensive multiphysics simulations with ansys, cst and autodesk CFD will first be carried out to evaluate the operational stability and performance. In addition, it will be clarified whether the printed copper fulfills the necessary vacuum and conductivity requirements after CNC processing, or whether galvanic copper plating should be carried out.

We report the successful high power RF conditioning of the revised 175 MHz FRANZ RFQ up to 80 kW CW, as well as successful beam commissioning up to 700 keV in pulsed operation. After a revision of the RFQ electrodes, the RFQ accelerates protons from 60 keV to 700 keV. The Frankfurt Neutron Source FRANZ will be a compact accelerator driven neutron source utilizing the 7Li(p,n)7Be reaction with a 2 MeV proton beam.

The Bonn Isochronous Cyclotron provides proton, deuteron, alpha and other light ion beams with a charge-to-mass ratio Q/A >= 1/2 and kinetic energies ranging from 7 to 14 MeV per nucleon. The beam is guided through a high-energy beam line (HEBL) to one of five experimental sites. The installation of the irradiation site for high-uniformity radiation hardness tests of Si detectors is now complete. Additionally, a neutron irradiation site will be commissioned soon. Here, a collimated neutron beam, generated by a stripping reaction of the deuteron beam in a carbon target, can be used for irradiation. To provide stable beam with constant optics for these experiments, the power supplies (PS) of all magnets in the HEBL will be replaced. The replacements must meet strict criteria regarding output current's stability, which were derived from measurements of the existing PS. In this spirit, a new corrector magnet PS system, enabling bipolar operation, PS/magnet operation safety/health and power consumption monitoring, is close to commissioning. Additionally, the cyclotron's extraction septum is upgraded to increase operation robustness. Here, an new antiseptum is designed together with a new septum blade holder, which is intended to be additively manufactured with the laser- powder bed fusion technique.

The Targeted Alpha Tumor Therapy and Other Oncological Solutions (TATTOOS) project at the Paul Scherrer Institute aims to produce large quantities of radioisotopes (in the range of GBq), mainly Terbium-149, for the promising Targeted Alpha-particle Therapy (TAT) against metastasized cancer. To facilitate this, a new electromagnetic separator is currently being designed. Comprising two spectrometer magnets, the design of the separator is crucial, with magnetic properties and fringe fields strongly influencing beam characteristics and purity of the collected radioisotopes. The first of these magnets is exposed to high radiation and has strong requirements on surrounding shielding materials. The required steel for effective fast-neutron shielding introduces distortions to the field in the spectrometers. In this paper, we explore techniques to mitigate the sensitivity of the magnet to nearby shielding materials. The investigation begins with simulating a dipole magnet, assessing produced fringe fields, and understanding the influence of surrounding steel walls. Various methods, including Rogowski-profile ends, mirror plates, field clamps, and end shunts, are investigated to correct the aberrations in the generated field. The evaluation of produced field maps is quantified using harmonics, and the potential for tuning fringe fields with a sequence of end shunts is explored. Ultimately, the paper identifies the most suitable method for implementation in the TATTOOS project.

The Spallation Neutron Source (SNS) employed over 200 cold plates in its Injection Kicker and quadrupole power supplies for semiconductor cooling. Each cold plate consisted of an aluminum base with interconnected copper tubes that were brazed together. Unfortunately, the durability of these plates was compromised over time due to corrosion of the copper tubes by de-ionized water. This corrosion led to the formation of small pinhole leaks, which became increasingly problematic in recent years, causing more frequent leaks and subsequent operational downtime for the SNS system. To tackle this issue, a novel solution was pursued involving the incorporation of stainless-steel tubes in the redesign. Two types of cold plates underwent rigorous simulations and extensive testing. One of the redesigned cold plates demonstrated competitive performance and was identified as a feasible replacement option. Consequently, a comprehensive initiative was executed to replace all cold plates.

In designing a high-power tungsten target, decay heat driven temperature rise in the spallation volume is a safety concern during maintenance and in loss of coolant accidents. As tungsten hydrates and becomes volatile in steam at above 800 ◦C, it is important to keep the target temperature below this threshold when active cooling is unavailable. Decay heat in a target is calculated with particle transport simulation codes combined with transmutation codes. The calculated decay heat usually differs depending on the nuclear cross sections and the decay particle transport models built in the code architecture. In this paper, we calculated decay heat of a water-cooled tungsten target using popular particle transport codes, FLUKA and MCNP6® paired with CINDER2008 and compared the results. The target-moderator-reflector (TMR) system is modeled with a water-cooled solid tungsten target, water premoderators, liquid hydrogen cold moderators and beryllium reflectors. Water-cooled stainless-steel shielding is modeled around the TMR system. The tungsten volume is clad with a thin layer of erosion/corrosion resistant material. This study provides information about the uncertainty range in decay heat prediction of high-power spallation targets for hazard analysis.

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.

The proton beam power limit for a solid-tungsten spallation target is largely determined by beam induced thermomechanical structural loads and decay heat power deposition, while its lifetime is limited by radiation damage and fatigue life of the target materials. In this paper, we studied the power limits of a stationary water-cooled solid tungsten target concept. Tantalum clad tungsten was considered as a reference case. Being a low activation material, zircaloy 2 cladding option was studied and its decay heat driven power limit was compared with the reference case. Zirconium alloys have proven operations records in spallation target and nuclear fission environments, supported by materials data obtained from post irradiation examinations. Recent study also demonstrated feasibility of diffusion bonding zirconium to tungsten using vanadium foil inter layer. Particle transport simulations code FLUKA was used to calculate energy deposition and decay heat power deposition in the target, based on the beam parameters technically feasible at the Second Target Station of the Spallation Neutron Source at Oak Ridge National Laboratory. The energy deposition data were used for flow, thermal, and structural analyses to determine the beam intensity limit on the target concept studied. The decay heat deposition data were used to calculate the transient temperature evolution in the tungsten volumes in a loss of coolant accident (LOCA) scenario to determine its beam power limit. For a 1.3 GeV proton beam, the power limit on a stationary target was 400 kW for a tantalum clad target model and 800 kW for a zircaloy 2 clad target model.