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The Target Station at the European Spallation Source (ESS) is designed to convert high power proton beam to high brightness neutron beams, for studying fundamental properties of materials. Upon commissioning of the 'beam on target' planned in 2022, the ESS linac will deliver lower energy proton beam than the design value of 2 GeV, for neutron production. The beam energy will then be gradually ramped up, with the sequential commissioning of the downstream part of the superconducting cryomodules. During neutron production, the beam intercepting devices and moderators are exposed to intense flux of primary and secondary particles, suffering from radiation induced structural degradation. The extent of the radiation damage depends on the energy and intensity of the impinging protons. Currently, the lifetime criteria determined for these components are based on the 2 GeV beam energy. To secure availability and reliability of the neutron production during the beam energy ramp-up phase, the radiation damage rates in these components should be reassessed and the lifetime criteria be adjusted. In this paper, we present the lifetime criteria for the beam intercepting devices and moderators for different beam energies, to serve for the planning of the maintenance and replacement schedule during the proton energy ramp-up phase. [ABSTRACT FROM AUTHOR]

The Spallation Neutron Source, in operation at the Oak Ridge National Laboratory since 2006, was designed to allow the addition of a second target station and an upgrade of the accelerator proton power. Both upgrades are now underway. This paper describes the evolution of the design of the target of the second target station with the emphasis on the effects of the proton beam footprint on the energy deposition in the target, stresses induced by the pulsed operation, and the importance of the residual heat. The moderator configurations and their optimization are discussed. With the utilization of pure parahydrogen moderators, small neutron beam cross-sections, and the specific optimization, neutron beams of the second target station will achieve exceptionally high peak brightness and time-averaged brightness. [ABSTRACT FROM AUTHOR]

As continuously shaped super-mirrors are becoming available, the conceptual design of focusing guides should explore a wider range of possibilities to accomplish an efficient neutron beam extraction. Starting from a desired phase-space volume at the sample position and using an upstream ray-tracing approach, the acceptance diagram of any focusing guide can be calculated at the moderator position. To ensure high brilliance transfer and homogeneous coverage, the acceptance diagram should be fully included in the neutron source emission phase-space volume. Following this idea, the guide system can be scaled into dimensionless geometric figures that convey performance limits for a desired cross-section reduction. Moreover, if we impose a monotonic increase of the reflection angle with divergence angle at the sample position, the shape of the mirror is analytically determined. This approach was applied in the design of a focusing guide for SNAP instrument at SNS, at ORNL, USA. The results of McStas simulations are presented with different options included. Our approach facilitates finding an optimal solution for connecting multiple guide pieces to avoid excessive losses and ensure a homogeneous phase space coverage. [ABSTRACT FROM AUTHOR]

In this contribution we describe NEPIR, the fast-neutron irradiation facility under construction at the 70 MeV cyclotron SPES facility of the INFN laboratory of Legnaro (LNL). NEPIR will be constructed in stages, according to the available funds. The initial configuration, based on a thick Be neutron production target, will be operational in 2022; it will be used for shielding studies against fast neutrons for space applications and to investigate neutron-induced Single Event Effects (SEE) in microelectronic devices and systems. In its final configuration NEPIR will have two target systems: one will deliver a Quasi Mono-energetic Neutron (QMN) beam, of general interest, with an adjustable energy peak in the 20–70 MeV range; the second target will deliver a specialized continuous energy neutron beam for studying the effects of fast neutrons produced in cosmic ray air-showers in electronic devices and systems. We review the use of NEPIR to characterize the sensitivity of electronics, describe the neutron production targets and the facility layout. In closing we describe ways, presently under investigation, to use the 15 MV XTU Tandem of LNL to produce nearly monochromatic fast neutrons that would complement the QMN system by allowing one to probe for SEE below 20 MeV. [ABSTRACT FROM AUTHOR]

In the development of the European Spallation Source, the engineering phase of the Neutron Beam Extraction System is approaching its end. Currently, prototyping is ongoing to verify and increase the understanding of the manufacturing limitations in relation to the engineering aspects and beam extraction requirements from the instruments. After that the manufacturing of the suite of 16 neutron beam port inserts (NBPI) and light shutter systems (LSS) are phased into final detail design and manufacturing. The NBPIs have been developed as a close collaboration between ESS' instruments design coordinators and intricately integrate a set of copper optics within a controlled atmosphere within the target monolith pressure vessel. The NBPIs therefore includes not only a processed atmosphere but also enables fine alignment of the optics assemblies within it, but also includes a system for inserting it into a very precisely aligned and measured position. Outside the NBPIs, along the neutron beam paths, sits the Neutron Beam Windows and sequentially, the LSS which incorporates an optical bridge beam guide before the beam enters the bunker area and the individual instrument beam transports. ESS have chosen the concept of LSS, which generates demanding requirements for alignment of moving shutter parts. These system parts are placed in the bunker area and bunker basement, areas that are partly accessible during maintenance periods. [ABSTRACT FROM AUTHOR]

64Cu is an emerging radionuclide of great interest in personalized nuclear medicine. It is produced by a cyclotron via the reaction 64Ni(p,n)64Cu. This production method increased during the last decades, because small biomedical cyclotrons can be easily installed close to the nuclear medicine department of a hospital. As a matter of fact, 64Ni is a very expensive target material. For this reason, an alternative 64Cu production method was investigated at ENEA by using the quasi-monochromatic 14 MeV fusion neutron beam made available at the Frascati Neutron Generator (FNG) located at the ENEA – Frascati Research Center. In particular, two nuclear reactions were studied: 65Cu(n,2n)64Cu and 64Zn(n,p)64Cu. The radiochemical analysis of the activated samples was performed at the ENEA-NMLNWM laboratory located in ENEA-Casaccia Research Center. The activity measurements were carried out at the ENEA-INMRI, located in the ENEA-Casaccia Research Center, with high metrological level conditions and by assuring their traceability to the 64Cu primary activity standard here developed and maintained. A prediction of the 64Cu production by means of the high-brilliance 14 MeV neutron source named Sorgentina is also discussed. [ABSTRACT FROM AUTHOR]

As continuously shaped super-mirrors are becoming available, the conceptual design of focusing guides should explore a wider range of possibilities to accomplish an efficient neutron beam extraction. Starting from a desired phase-space volume at the sample position and using an upstream ray-tracing approach, the acceptance diagram of any focusing guide can be calculated at the moderator position. To ensure high brilliance transfer and homogeneous coverage, the acceptance diagram should be fully included in the neutron source emission phase-space volume. Following this idea, the guide system can be scaled into dimensionless geometric figures that convey performance limits for a desired cross-section reduction. Moreover, if we impose a monotonic increase of the reflection angle with divergence angle at the sample position, the shape of the mirror is analytically determined. This approach was applied in the design of a focusing guide for SNAP instrument at SNS, at ORNL, USA. The results of McStas simulations are presented with different options included. Our approach facilitates finding an optimal solution for connecting multiple guide pieces to avoid excessive losses and ensure a homogeneous phase space coverage. [ABSTRACT FROM AUTHOR]