scholarly journals Design of the third-generation neutron spallation target for the CERN’s n_TOF facility

2020 ◽  
Vol 22 (2-3) ◽  
pp. 221-231
Author(s):  
Raffaele Esposito ◽  
Marco Calviani
Keyword(s):  
Particle Physics ◽  
Cooling Water ◽  
Nuclear Astrophysics ◽  
Lead Target ◽  
Third Generation ◽  
Spallation Target ◽  
Neutron Spallation Source ◽  
European Laboratory ◽  
Neutron Time ◽  
Spallation Source

The neutron Time-Of-Flight (n_TOF) facility at the European Laboratory for Particle Physics (CERN) is a pulsed white-spectrum neutron spallation source producing neutrons for two experimental areas: EAR1, located 185 m downstream of the spallation target, and EAR2, located 20 m above the target. The facility is based on a lead target impacted by a high-intensity 20 GeV/c proton beam. It is designed to study neutron-nucleus interactions for neutron kinetic energies from a few meV to several GeV, with applications in nuclear astrophysics, nuclear technology, and medical research. The facility is undergoing a major upgrade in 2019–2020, which will include the installation of the new third-generation target. The second-generation target consists in a water-cooled lead cylinder, while the new target will be cooled by nitrogen to avoid erosion-corrosion phenomena and contamination of the cooling water with radioactive lead spallation products. The new design will be optimized also for the vertical flight path. The operation of the new spallation target will start in 2021. This paper presents an overview on the evolution of the design and on the related R&D activities (including beam irradiation tests) carried out to ensure the best performance for both experimental areas and avoid the contamination issues of the previous targets.

scholarly journals Status and perspectives of the neutron time-of-flight facility n_TOF at CERN

2020 ◽  
Vol 239 ◽  
pp. 17001
Author(s):  
E. Chiaveri ◽  
O. Aberle ◽  
V. Alcayne ◽  
S. Amaducci ◽  
J. Andrzejewski ◽  
...  
Keyword(s):  
Time Of Flight ◽  
Nuclear Astrophysics ◽  
Neutron Cross Section ◽  
Medical Applications ◽  
Spallation Target ◽  
The Future ◽  
Wide Energy ◽  
Neutron Time ◽  
Instantaneous Neutron ◽  
Open Issues

Since the start of its operation in 2001, based on an idea of Prof. Carlo Rubbia [1], the neutron time of-flight facility of CERN, n_TOF, has become one of the most forefront neutron facilities in the world for wide-energy spectrum neutron cross section measurements. Thanks to the combination of excellent neutron energy resolution and high instantaneous neutron flux available in the two experimental areas, the second of which has been constructed in 2014, n_TOF is providing a wealth of new data on neutron-induced reactions of interest for nuclear astrophysics, advanced nuclear technologies and medical applications. The unique features of the facility will continue to be exploited in the future, to perform challenging new measurements addressing the still open issues and long-standing quests in the field of neutron physics. In this document the main characteristics of the n_TOF facility and their relevance for neutron studies in the different areas of research will be outlined, addressing the possible future contribution of n_TOF in the fields of nuclear astrophysics, nuclear technologies and medical applications. In addition, the future perspectives of the facility will be described including the upgrade of the spallation target, the setup of an imaging installation and the construction of a new irradiation area.

scholarly journals Design of the third-generation lead-based neutron spallation target for the neutron time-of-flight facility at CERN

2021 ◽  
Vol 24 (9) ◽  
Author(s):  
R. Esposito ◽  
M. Calviani ◽  
O. Aberle ◽  
M. Barbagallo ◽  
D. Cano-Ott ◽  
...  
Keyword(s):  
Time Of Flight ◽  
Third Generation ◽  
Spallation Target ◽  
The Third ◽  
Neutron Time

scholarly journals Radiochemical separation of 7Be from the cooling water of the neutron spallation source SINQ at PSI

2013 ◽  
Vol 101 (8) ◽  
pp. 509-514 ◽  
Author(s):  
D. Schumann ◽  
M. Ayranov ◽  
T. Stowasser ◽  
L. Gialanella ◽  
A. di Leva ◽  
...  
Keyword(s):  
Ion Beam ◽  
Cooling Water ◽  
Fast Neutrons ◽  
Separation System ◽  
Highly Active ◽  
Spallation Reactions ◽  
Beam Production ◽  
Neutron Spallation Source ◽  
Spallation Source ◽  
Cooling Loop

Summary 7Be is a key radionuclide for investigation of several astrophysical processes and phenomena. In addition, it is used as a tracer in wear measurements. It is produced in considerable amounts in the cooling water (D2O) of the Spallation Induced Neutron Source (SINQ) facility at PSI by spallation reactions on 16O with the generated fast neutrons. A shielded ion-exchange filter containing 100 mL of the mixed-bed ion exchanger LEWATIT was installed as a bypass for the cooling water into the cooling loop of SINQ for three months. The collected activity of 7Be was in the range of several hundred GBq. Further, the 7Be was separated and purified in a hot-cell remotely-controlled using a separation system installed. With the exception of 10Be, radioactive byproducts can be neglected, so that this cooling water could serve as an ideal source for highly active 7Be-samples. The facility is capable of producing 7Be with activities up to 1 TBq per year. The 7Be sample preparation is described in detail and the possible uses are discussed. In particular some preliminary results of 7Be ion beam production are presented.

scholarly journals From nuclear astrophysics to fundamental nuclear physics: challenging experimental approaches at n_TOF (CERN)

2021 ◽  
Vol 252 ◽  
pp. 05002
Author(s):  
Agatino Musumarra
Keyword(s):  
Nuclear Physics ◽  
Scattering Length ◽  
Nuclear Astrophysics ◽  
Neutron Cross Section ◽  
Neutron Spallation Source ◽  
Spallation Source ◽  
Body Kinematic ◽  
Experimental Approaches ◽  
Leading Neutron ◽  
Three Body

The n_TOF installation at CERN is one of the leading neutron facilities worldwide undergoing a major update of the neutron spallation source. The update will provide improved n-TOF resolution in the experimental areas and the possibility to perform neutron cross section measurements at very high neutron flux (NEAR-Station). The renewed capabilities of the facility must be supported by smart and non-conventional experimental approaches. In this framework two examples will be reported. The first one concerns the measurement of a key reaction channel involved in Primordial Nucleosynthesis: the 7Be(n, α), by using a radioactive 7Be target. The second one provides a state-of-the-art scenario for the n-n scattering length measurement. This will be performed by neutron-deuteron (n-d) breakup three-body reaction. In this case, the envisaged experimental setup will provide a complete three-body kinematic reconstruction. By these important physics cases we are crossing the technological frontiers for charged particle and neutron detection.

Mechanical Spectroscopy Investigation of Liquid Pb-Bi Alloys

2012 ◽  
Vol 184 ◽  
pp. 434-439 ◽  
Author(s):  
Roberto Montanari ◽  
Alessandra Varone
Keyword(s):  
Distribution Functions ◽  
X Ray Diffraction ◽  
Mechanical Spectroscopy ◽  
X Ray ◽  
Neutron Spallation Source ◽  
Driven System ◽  
Spallation Source ◽  
Accelerator Driven System ◽  
The Mean ◽  
Diffraction Patterns

Liquid Pb–Bi eutectic alloy has been selected as coolant and neutron spallation source for the development of MYRRHA, an accelerator driven system. The alloy has been characterized in liquid state from melting (125 °C) to 650 °C by mechanical spectroscopy. Experiments have been carried out using hollow reeds of austenitic stainless steel filled with the Pb-Bi alloy and sealed at the extremities. From 350 °C to 520 °C modulus shows a remarkable drop accompanied by a broad internal friction maximum. In the same temperature range radial distribution functions, determined from X-ray diffraction patterns, evidenced variations of the mean distance between the 1st nearest neighbour atoms. The anelastic phenomena have been attributed to a structural re-arrangement of liquid metal. For comparison, other alloys of the Pb-Bi system with hypo-eutectic composition have been investigated.

scholarly journals ANNI – A pulsed cold neutron beam facility for particle physics at the ESS

2019 ◽  
Vol 219 ◽  
pp. 10003 ◽  
Author(s):  
Torsten Soldner ◽  
Hartmut Abele ◽  
Gertrud Konrad ◽  
Bastian Märkisch ◽  
Florian M. Piegsa ◽  
...  
Keyword(s):  
Neutron Beam ◽  
Particle Physics ◽  
Cold Neutron ◽  
Expected Gain ◽  
Cold Neutron Beam ◽  
Systematic Effects ◽  
Present Design ◽  
Spallation Source ◽  
Pulse Structure ◽  
And Performance

Pulsed beams have tremendous advantages for precision experiments with cold neutrons. In order to minimise and measure systematic effects, they are used at continuous sources in spite of the related substantial decrease in intensity. At the European Spallation Source ESS these experiments will profit from the pulse structure of the source and its 50 times higher peak brightness compared to the most intense reactor facilities, making novel concepts feasible. Therefore, the cold neutron beam facility for particle physics ANNI was proposed as part of the ESS instrument suite. The proposed design has been re-optimised to take into account the present ESS cold moderator layout. We present design considerations, the optimised instrument parameters and performance, and expected gain factors for several reference experiments.

scholarly journals Biodiversity Literature Repository: Building the customized FAIR repository by using custom metadata

2021 ◽  
Vol 5 ◽  
Author(s):  
Alexandros Ioannidis-Pantopikos ◽  
Donat Agosti
Keyword(s):  
Particle Physics ◽  
Building Blocks ◽  
General Purpose ◽  
Digital Object Identifier ◽  
Global Biodiversity Information Facility ◽  
Local Networks ◽  
Representational State Transfer ◽  
Processing Pipeline ◽  
European Laboratory ◽  
Machine Readable

In the landscape of general-purpose repositories, Zenodo was built at the European Laboratory for Particle Physics' (CERN) data center to facilitate the sharing and preservation of the long tail of research across all disciplines and scientific domains. Given Zenodo’s long tradition of making research artifacts FAIR (Findable, Accessible, Interoperable, and Reusable), there are still challenges in applying these principles effectively when serving the needs of specific research domains. Plazi’s biodiversity taxonomic literature processing pipeline liberates data from publications, making it FAIR via extensive metadata, the minting of a DataCite Digital Object Identifier (DOI), a licence and both human- and machine-readable output provided by Zenodo, and accessible via the Biodiversity Literature Repository community at Zenodo. The deposits (e.g., taxonomic treatments, figures) are an example of how local networks of information can be formally linked to explicit resources in a broader context of other platforms like GBIF (Global Biodiversity Information Facility). In the context of biodiversity taxonomic literature data workflows, a general-purpose repository’s traditional submission approach is not enough to preserve rich metadata and to capture highly interlinked objects, such as taxonomic treatments and digital specimens. As a prerequisite to serve these use cases and ensure that the artifacts remain FAIR, Zenodo introduced the concept of custom metadata, which allows enhancing submissions such as figures or taxonomic treatments (see as an example the treatment of Eurygyrus peloponnesius) with custom keywords, based on terms from common biodiversity vocabularies like Darwin Core and Audubon Core and with an explicit link to the respective vocabulary term. The aforementioned pipelines and features are designed to be served first and foremost using public Representational State Transfer Application Programming Interfaces (REST APIs) and open web technologies like webhooks. This approach allows researchers and platforms to integrate existing and new automated workflows into Zenodo and thus empowers research communities to create self-sustained cross-platform ecosystems. The BiCIKL project (Biodiversity Community Integrated Knowledge Library) exemplifies how repositories and tools can become building blocks for broader adoption of the FAIR principles. Starting with the above literature processing pipeline, the concepts of and resulting FAIR data, with a focus on the custom metadata used to enhance the deposits, will be explained.

scholarly journals Wiederverwertung ausgehobener Molasse basierend auf geologischer Untergrundmodellierung für den geplanten 100 km Teilchenbeschleuniger-Tunnel am CERN nahe Genf, Schweiz

2020 ◽  
Vol 165 (12) ◽  
pp. 631-638
Author(s):  
Maximilian Haas
Keyword(s):  
Higgs Boson ◽  
Particle Physics ◽  
European Laboratory

ZusammenfassungDas CERN (Conseil Européen pour la Recherche Nucléaire bzw. European Laboratory for Particle Physics) ist eine weltweit führende internationale Forschungseinrichtung auf dem Gebiet der Hochenergie- und Teilchenphysik. Die Erforschung der grundlegenden Bausteine des Universums und ihrer Interaktionen lieferte in den vergangenen Jahrzehnten bahnbrechende Erkenntnisse, die im experimentellen Nachweis des Higgs-Boson im Juli 2012 gipfelten. Um die in diesem Zusammenhang erforschten Erkenntnisse weiter zu vertiefen und noch unbeantwortete Fragen nach dem Ursprung und der Funktion des Universums zu beantworten, hat eine internationale Gemeinschaft von über 150 Instituten weltweit am CERN eine Studie für ein Forschungsprogramm mit einer neuen, leistungsfähigeren Teilchenbeschleunigerinfrastruktur initiiert. Die Future Circular Collider (FCC) Studie schließt die dafür erforderlichen unterirdischen Tunnel, Kavernen und Schächte und die damit verbundenen Konstruktionen an der Oberfläche mit ein. Die Infrastruktur ist so ausgelegt, um im Zusammenschluss mit den bereits bestehenden Teilchenbeschleunigern am CERN (z. B. PSB, PS, SPS, LHC) zu funktionieren. Im Rahmen des Projekts wurden seit 2014 die ersten technischen Machbarkeitsstudien in den verschiedensten Gebieten, unter anderem Geologie und Konstruktion des Tunnels, der sich über ca. 100 km im teils westschweizerischen und teils französischen Molassebecken erstreckt, durchgeführt, sodass FCC nach derzeitigem Planungsstand um das Jahr 2040 in Betrieb gehen kann. Im Zuge dessen ist ein geologisches Untergrundmodell unerlässlich, um einen sicheren Bau unterirdischer Infrastruktur zu gewährleisten und die Baumethode auf die Geologie abzustimmen. Ein entscheidender Faktor neben dem geologischen Modell ist die Wiederverwertbarkeit des ausgehobenen Molasse-Materials mit einem Volumen von etwa 9 Mio. m3 sowohl aus technischer als auch rechtlicher, gesellschaftspolitischer und sozio-ökonomischer Sicht.Dieser Artikel soll einen Einblick in diese beiden Machbarkeitsstudien des FCC Projekts geben, sowie Ansätze der geologischen, petrophysikalischen, geotechnischen und mineralogisch-chemischen Analysen präsentieren, die zur Beantwortung der Wiederverwertung dienen und in weiterer Folge in das geologische Untergrundmodell einfließen werden.

scholarly journals 4D Bragg Edge Tomography of Directional Ice Templated Graphite Electrodes

2020 ◽  
Vol 6 (12) ◽  
pp. 136
Author(s):  
Ralf F. Ziesche ◽  
Anton S. Tremsin ◽  
Chun Huang ◽  
Chun Tan ◽  
Patrick S. Grant ◽  
...  
Keyword(s):  
Li Ion Battery ◽  
Graphite Electrodes ◽  
Neutron Spallation Source ◽  
Spallation Source ◽  
Li Ion ◽  
Tomography Method ◽  
First Time ◽  
Pulsed Neutron ◽  
Tomography Data ◽  
Insight Into

Bragg edge tomography was carried out on novel, ultra-thick, directional ice templated graphite electrodes for Li-ion battery cells to visualise the distribution of graphite and stable lithiation phases, namely LiC12 and LiC6. The four-dimensional Bragg edge, wavelength-resolved neutron tomography technique allowed the investigation of the crystallographic lithiation states and comparison with the electrode state of charge. The tomographic imaging technique provided insight into the crystallographic changes during de-/lithiation over the electrode thickness by mapping the attenuation curves and Bragg edge parameters with a spatial resolution of approximately 300 µm. This feasibility study was performed on the IMAT beamline at the ISIS pulsed neutron spallation source, UK, and was the first time the 4D Bragg edge tomography method was applied to Li-ion battery electrodes. The utility of the technique was further enhanced by correlation with corresponding X-ray tomography data obtained at the Diamond Light Source, UK.

scholarly journals A Vertex-Aligned Model for Packing 4-Hexagonal Clusters in a Regular Hexagonal Container

Symmetry ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 700
Author(s):  
Marina Prvan ◽  
Arijana Burazin Mišura ◽  
Zoltan Gecse ◽  
Julije Ožegović
Keyword(s):  
Compact Muon Solenoid ◽  
Particle Physics ◽  
Hadron Collider ◽  
Number Of Clusters ◽  
Geometrical Properties ◽  
European Laboratory ◽  
Packing Efficiency ◽  
Packing Scheme ◽  
Container Model ◽  
Maximal Packing

This paper deals with a problem the packing polyhex clusters in a regular hexagonal container. It is a common problem in many applications with various cluster shapes used, but symmetric polyhex is the most useful in engineering due to its geometrical properties. Hence, we concentrate on mathematical modeling in such an application, where using the “bee” tetrahex is chosen for the new Compact Muon Solenoid (CMS) design upgrade, which is one of four detectors used in Large Hadron Collider (LHC) experiment at European Laboratory for Particle Physics (CERN). We start from the existing hexagonal containers with hexagonal cells packed inside, and uniform clustering applied. We compare the center-aligned (CA) and vertex-aligned (VA) models, analyzing cluster rotations providing the increased packing efficiency. We formally describe the geometrical properties of clustering approaches and show that cluster sharing is inevitable at the container border with uniform clustering. In addition, we propose a new vertex-aligned model decreasing the number of shared clusters in the uniform scenario, but with a smaller number of clusters contained inside the container. Also, we describe a non-uniform tetrahex cluster packing scheme in the proposed container model. With the proposed cluster packing solution, it is accomplished that all clusters are contained inside the container region. Since cluster-sharing is completely avoided at the container border, the maximal packing efficiency is obtained compared to the existing models.

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