Baseline Design of a Low Energy Neutron Source at ESS-Bilbao

Progress in Nuclear Energy, 1996

The Advanced Neutron Source (ANS) is a new experimental facility planned to meet the need for an intense steady-state source of neutrons. The facility will be build around a new research reactor with a fission power of about 330 MW, producing an unprecedented flux that will provide the most intense beams of steady-state neutrons in the world. This paper outlines the overall scientific mission and technical objectives of this project, defines the regulatory approach that is likely to be applied, and presents a summary of the facility layout, the major plant systems, and the reactor and experiment systems. Detailed discussions are then given related to the design of the reactor core and various options evaluated, and the approach taken on safety and severe accident analyses. A summary is also included on the topic of environmental compliance and several key aspects that must be addressed to ensure compliance in that area.

2019

This CRS report focuses on the Spallation Neutron Source (SNS), a new Department of Energy-funded research facility, which is scheduled for construction at the Oak Ridge National Laboratory in eastern Tennessee. The facility is intended to generate and use pulsed neutron beams to study the structural properties of a wide range of materials. The report describes the SNS's management, project costs, schedule, site selection, and funding, and discusses issues raised by some congressional critics of the project, such as management problems, potential cost overruns, and schedule delays. Technical information about the project as well as excerpts from relevant legislation are appended. The report will be updated as appropriate.

1999

This CRS report focuses on the Spallation Neutron Source (SNS), a new Department of Energy-funded research facility, which is scheduled for construction at the Oak Ridge National Laboratory in eastern Tennessee. The facility is intended to generate and use pulsed neutron beams to study the structural properties of a wide range of materials. The report describes the SNS's management, project costs, schedule, site selection, and funding, and discusses issues raised by some congressional critics of the project, such as management problems, potential cost overruns, and schedule delays. Technical information about the project as well as excerpts from relevant legislation are appended. The report will be updated as appropriate.

In the course of discussing different target types for their suitability in the European Spallation Source (ESS) one main focus was on neutronics' performance. Diverse concepts have been assessed baselining some preliminary engineering and geometrical details and including some optimization. With the restrictions and resulting uncertainty imposed by the lack of detailed designs optimizations at the time of compiling this paper, the conclusion drawn is basically that there is a little difference in the neutronic yield of the investigated targets. Other criteria like safety, environmental compatibility, reliability and cost will thus dominate the choice of an ESS target.

Journal of Neutron Research

The European Spallation Source (ESS) 1 presently under construction in Lund, Sweden, is designed to become the most powerful facility ever built for research with neutrons. The source of neutrons has at its core a moderator system of unprecedented brightness, which is due to the adoption of the new concept of low-dimensional moderators (a factor 2.5 brighter than the conventional volume moderator initially foreseen for ESS). This moderator system, placed above the large rotating tungsten spallation target, will serve a suite of fifteen neutron scattering instruments which are presently being installed, aiming at starting the user program in 2027, before reaching the full scope of twenty-two instruments at a later date. The facility was designed with the provision for upgrades: a grid of forty-two beamports was built around the moderators, allowing for more instruments to be added to the suite in unoccupied locations. The possibility to install new instruments can profit from an additional degree of flexibility that was not present in the initial design of ESS: the initial design consisted of two identical, large-volume moderator systems, one above and one below the spallation target, which took all the space allocated around the target for the placement of neutron sources. The adoption of the novel design based on the low-dimensional moderator concept resulted not only in a brighter source, but also in a configuration where only a single moderator system, placed above the spallation target, was sufficient and optimal to serve all the instruments in the initial suite. This left the space below the target available for the placement of a new source. Allowing by design each of the forty-two beamports to view either the upper or lower moderator system, it increased the upgrade possibilities of ESS. A second source, with different characteristics from the first one, can now be designed and installed; the combination of two complementary moderator systems would then not only enhance the range of possibilities of ESS but even enable developments of new instrument concepts. The HighNESS project (development of High intensity Neutron source at the European Spallation Source) 2 is a three-years EU project whose main goal is to design such a second moderator system within the existing ESS infrastructure. It will provide an engineering study for a cold-neutron moderator, and technical design studies for sources of very cold neutrons (VCN) and ultra-cold neutrons (UCN). The complementarity of this moderator system to the upper, bi-spectral high-brightness moderator is twofold: first, its high total intensity of cold neutrons enables applications for which this parameter, rather than highest possible brightness, is of paramount importance; second, the extended long-wavelength capabilities generate opportunities to develop novel instrument concepts able to take advantage of VCN and for a next generation of projects with UCN. The first part of the HighNESS project, which started in October 2020, was dedicated to the design of an intense source of cold neutrons, based on a large-volume liquid deuterium moderator. For the tasks of designing VCN

2015

2009

Physics Procedia, 2014

A simple and easy-to-use compact neutron source based on a low power level proton accelerator (proton energy 3.5 MeV and 0.35 kW beam power) at Kyoto University was designed with the conception of low cost, compact size, high safety and intensive thermal neutron flux via Monte Carlo method with PHITS code. By utilizing (p, n) reactions in a beryllium target coupled to a polyethylene moderator and graphite reflector with a wing configuration, this facility is expected to produce time-averaged thermal neutron fluxes suitable for neutron scattering and development of instrumentation, and play a role in educating students in neutron science and performing research with neutrons. Borated polyethylene (BPE) and ordinary concrete were combined to shield the neutron and photon. By using niobium as target backing and water as cooler, it is promising to cope with the problem of thermal damage and hydrogen embrittlement damage. The sizes of moderator and reflector are optimized to have thermal neutron flux as high as possible, while keeping the low ratio of fast neutron flux to thermal neutron flux. The neutron and gamma dose equivalent rates were evaluated and the current shielding configuration is acceptable.

AIP Conference Proceedings, 2005

A new quasi-monoenergetic neutron beam facility has been constructed at the The Svedberg Laboratory (TSL) in Uppsala, Sweden. Key features include an energy range of 20 to 175 MeV, high fluxes, and the possibility of large-area fields. Besides cross-section measurements, the new facility has been designed specifically to provide optimal conditions for testing of single-event effects in electronics and for dosimetry development. First results of the beam characterization measurements performed in early 2004 are reported.