| 1. |
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- 2018
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In: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 58:1
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Research review (peer-reviewed)
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| 2. |
- Bombarda, F., et al.
(author)
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Runaway electron beam control
- 2019
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In: Plasma Physics and Controlled Fusion. - : IOP Publishing. - 1361-6587 .- 0741-3335. ; 61:1
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Journal article (peer-reviewed)
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| 3. |
- Krasilnikov, A., et al.
(author)
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Evidence of 9 Be + p nuclear reactions during 2ω CH and hydrogen minority ICRH in JET-ILW hydrogen and deuterium plasmas
- 2018
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In: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 58:2
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Journal article (peer-reviewed)abstract
- The intensity of 9Be + p nuclear fusion reactions was experimentally studied during second harmonic (2ω CH) ion-cyclotron resonance heating (ICRH) and further analyzed during fundamental hydrogen minority ICRH of JET-ILW hydrogen and deuterium plasmas. In relatively low-density plasmas with a high ICRH power, a population of fast H+ ions was created and measured by neutral particle analyzers. Primary and secondary nuclear reaction products, due to 9Be + p interaction, were observed with fast ion loss detectors, γ-ray spectrometers and neutron flux monitors and spectrometers. The possibility of using 9Be(p, d)2α and 9Be(p, α)6Li nuclear reactions to create a population of fast alpha particles and study their behaviour in non-active stage of ITER operation is discussed in the paper.
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| 12. |
- Joffrin, E., et al.
(author)
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Overview of the JET preparation for deuterium-tritium operation with the ITER like-wall
- 2019
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In: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 59:11
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Research review (peer-reviewed)abstract
- For the past several years, the JET scientific programme (Pamela et al 2007 Fusion Eng. Des. 82 590) has been engaged in a multi-campaign effort, including experiments in D, H and T, leading up to 2020 and the first experiments with 50%/50% D-T mixtures since 1997 and the first ever D-T plasmas with the ITER mix of plasma-facing component materials. For this purpose, a concerted physics and technology programme was launched with a view to prepare the D-T campaign (DTE2). This paper addresses the key elements developed by the JET programme directly contributing to the D-T preparation. This intense preparation includes the review of the physics basis for the D-T operational scenarios, including the fusion power predictions through first principle and integrated modelling, and the impact of isotopes in the operation and physics of D-T plasmas (thermal and particle transport, high confinement mode (H-mode) access, Be and W erosion, fuel recovery, etc). This effort also requires improving several aspects of plasma operation for DTE2, such as real time control schemes, heat load control, disruption avoidance and a mitigation system (including the installation of a new shattered pellet injector), novel ion cyclotron resonance heating schemes (such as the three-ions scheme), new diagnostics (neutron camera and spectrometer, active Alfven eigenmode antennas, neutral gauges, radiation hard imaging systems...) and the calibration of the JET neutron diagnostics at 14 MeV for accurate fusion power measurement. The active preparation of JET for the 2020 D-T campaign provides an incomparable source of information and a basis for the future D-T operation of ITER, and it is also foreseen that a large number of key physics issues will be addressed in support of burning plasmas.
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| 25. |
- Murari, A., et al.
(author)
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A control oriented strategy of disruption prediction to avoid the configuration collapse of tokamak reactors
- 2024
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In: Nature Communications. - 2041-1723 .- 2041-1723. ; 15:1
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Journal article (peer-reviewed)abstract
- The objective of thermonuclear fusion consists of producing electricity from the coalescence of light nuclei in high temperature plasmas. The most promising route to fusion envisages the confinement of such plasmas with magnetic fields, whose most studied configuration is the tokamak. Disruptions are catastrophic collapses affecting all tokamak devices and one of the main potential showstoppers on the route to a commercial reactor. In this work we report how, deploying innovative analysis methods on thousands of JET experiments covering the isotopic compositions from hydrogen to full tritium and including the major D-T campaign, the nature of the various forms of collapse is investigated in all phases of the discharges. An original approach to proximity detection has been developed, which allows determining both the probability of and the time interval remaining before an incoming disruption, with adaptive, from scratch, real time compatible techniques. The results indicate that physics based prediction and control tools can be developed, to deploy realistic strategies of disruption avoidance and prevention, meeting the requirements of the next generation of devices.
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| 26. |
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| 27. |
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| 28. |
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- 2018
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In: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 58:9
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Journal article (peer-reviewed)
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| 29. |
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| 30. |
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| 31. |
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Overview of the JET results
- 2015
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In: Nuclear Fusion. - : IOP Publishing. - 0029-5515 .- 1741-4326. ; 55:10
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Journal article (peer-reviewed)
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| 32. |
- Abel, I, et al.
(author)
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Overview of the JET results with the ITER-like wall
- 2013
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In: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 53:10, s. 104002-
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Journal article (peer-reviewed)abstract
- Following the completion in May 2011 of the shutdown for the installation of the beryllium wall and the tungsten divertor, the first set of JET campaigns have addressed the investigation of the retention properties and the development of operational scenarios with the new plasma-facing materials. The large reduction in the carbon content (more than a factor ten) led to a much lower Z(eff) (1.2-1.4) during L- and H-mode plasmas, and radiation during the burn-through phase of the plasma initiation with the consequence that breakdown failures are almost absent. Gas balance experiments have shown that the fuel retention rate with the new wall is substantially reduced with respect to the C wall. The re-establishment of the baseline H-mode and hybrid scenarios compatible with the new wall has required an optimization of the control of metallic impurity sources and heat loads. Stable type-I ELMy H-mode regimes with H-98,H-y2 close to 1 and beta(N) similar to 1.6 have been achieved using gas injection. ELM frequency is a key factor for the control of the metallic impurity accumulation. Pedestal temperatures tend to be lower with the new wall, leading to reduced confinement, but nitrogen seeding restores high pedestal temperatures and confinement. Compared with the carbon wall, major disruptions with the new wall show a lower radiated power and a slower current quench. The higher heat loads on Be wall plasma-facing components due to lower radiation made the routine use of massive gas injection for disruption mitigation essential.
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| 33. |
- Romanelli, F, et al.
(author)
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Overview of the JET results
- 2011
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In: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 51:9
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Journal article (peer-reviewed)abstract
- Since the last IAEA Conference JET has been in operation for one year with a programmatic focus on the qualification of ITER operating scenarios, the consolidation of ITER design choices and preparation for plasma operation with the ITER-like wall presently being installed in JET. Good progress has been achieved, including stationary ELMy H-mode operation at 4.5 MA. The high confinement hybrid scenario has been extended to high triangularity, lower ρ*and to pulse lengths comparable to the resistive time. The steady-state scenario has also been extended to lower ρ*and ν*and optimized to simultaneously achieve, under stationary conditions, ITER-like values of all other relevant normalized parameters. A dedicated helium campaign has allowed key aspects of plasma control and H-mode operation for the ITER non-activated phase to be evaluated. Effective sawtooth control by fast ions has been demonstrated with3He minority ICRH, a scenario with negligible minority current drive. Edge localized mode (ELM) control studies using external n = 1 and n = 2 perturbation fields have found a resonance effect in ELM frequency for specific q95values. Complete ELM suppression has, however, not been observed, even with an edge Chirikov parameter larger than 1. Pellet ELM pacing has been demonstrated and the minimum pellet size needed to trigger an ELM has been estimated. For both natural and mitigated ELMs a broadening of the divertor ELM-wetted area with increasing ELM size has been found. In disruption studies with massive gas injection up to 50% of the thermal energy could be radiated before, and 20% during, the thermal quench. Halo currents could be reduced by 60% and, using argon/deuterium and neon/deuterium gas mixtures, runaway electron generation could be avoided. Most objectives of the ITER-like ICRH antenna have been demonstrated; matching with closely packed straps, ELM resilience, scattering matrix arc detection and operation at high power density (6.2 MW m-2) and antenna strap voltages (42 kV). Coupling measurements are in very good agreement with TOPICA modelling. © 2011 IAEA, Vienna.
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| 34. |
- Plompen, A. J. M., et al.
(author)
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The joint evaluated fission and fusion nuclear data library, JEFF-3.3
- 2020
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In: European Physical Journal A. - : Springer Science and Business Media LLC. - 1434-6001 .- 1434-601X. ; 56:7
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Research review (peer-reviewed)abstract
- The joint evaluated fission and fusion nuclear data library 3.3 is described. New evaluations for neutron-induced interactions with the major actinides 235U, 238U and 239Pu, on 241Am and 23Na, 59Ni, Cr, Cu, Zr, Cd, Hf, W, Au, Pb and Bi are presented. It includes new fission yields, prompt fission neutron spectra and average number of neutrons per fission. In addition, new data for radioactive decay, thermal neutron scattering, gamma-ray emission, neutron activation, delayed neutrons and displacement damage are presented. JEFF-3.3 was complemented by files from the TENDL project. The libraries for photon, proton, deuteron, triton, helion and alpha-particle induced reactions are from TENDL-2017. The demands for uncertainty quantification in modeling led to many new covariance data for the evaluations. A comparison between results from model calculations using the JEFF-3.3 library and those from benchmark experiments for criticality, delayed neutron yields, shielding and decay heat, reveals that JEFF-3.3 performes very well for a wide range of nuclear technology applications, in particular nuclear energy.
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| 35. |
- Murari, A., et al.
(author)
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Measuring the radiation field and radiation hard detectors at JET : Recent developments
- 2008
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In: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 593:3, s. 492-504
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Journal article (peer-reviewed)abstract
- Since in ITER the radiation field will be much more demanding than that of present day devices, research programmes at JET are aimed at developing radiation hard diagnostics and related components. Initially, significant efforts are devoted to determining the radiation field of both the plasma and in the immediate environment with better accuracy. New developments in MCNP calculations and dedicated measurements provide useful information about the radiation field in the Torus Hall, even during non-operational periods. The effect of using Beryllium in the near future for JET first wall, is being assessed. New materials for activation samples are under consideration and will be tested to improve the calibration accuracy of JET neutron diagnostics. The long-term goal of this work is to obtain spectrometric information from an appropriate combination of different materials. Several studies are under way to modify the radiation field at the detectors by using LiH or pure water as neutron filters, to alleviate the problem of the background in gamma-ray measurements. A suite of radiation hard detectors for neutrons, magnetic field and charged particles are being developed. Super-heated fluid neutron detectors, used for yield and imaging, are being upgraded, in order to provide a broadband spectrometric capability. Chemical vapour deposited diamond diodes are being qualified as counters and as spectrometers. Prototypes of Hall probes made of InSb have been installed on the machine and have provided some preliminary results. Si-on-insulator detectors are under development for use in neutral particle analysers and are currently being bench-tested. Some attention is being devoted to optical components, fibres and mirrors, and to investigating radiation hard electronics using reconfigurable Field Programmable Gate Arrays.
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| 36. |
- Ballarini, F., et al.
(author)
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The physics of the FLUKA code : Recent developments
- 2007
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In: Advances in Space Research. - Elsevier : Elsevier BV. - 0273-1177 .- 1879-1948. ; 40:9, s. 1339-1349
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Journal article (peer-reviewed)abstract
- FLUKA is a Monte-Carlo code able to simulate interaction and transport of hadrons, heavy ions and electromagnetic particles from few keV (or thermal neutron) to cosmic ray energies in whichever material. The highest priority in the design and development of the code has always been the implementation and improvement of sound and modern physical models. A summary of the FLUKA physical models is given, while recent developments are described in detail: among the others, extensions of the intermediate energy hadronic interaction generator, refinements in photon cross sections and interaction models, analytical on-line evolution of radio-activation and remnant dose. In particular, new developments in the nucleus-nucleus interaction models are discussed. Comparisons with experimental data and examples of applications of relevance for space radiation are also provided.
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| 37. |
- Batistoni, P., et al.
(author)
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Technological exploitation of Deuterium-Tritium operations at JET in support of ITER design, operation and safety
- 2016
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In: Fusion engineering and design. - : ELSEVIER SCIENCE SA. - 0920-3796 .- 1873-7196. ; 109, s. 278-285
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Journal article (peer-reviewed)abstract
- Within the framework of the EUROfusion programme, a work-package of technology projects (WPJET3) is being carried out in conjunction with the planned Deuterium-Tritium experiment on JET (DTE2) with the objective of maximising the scientific and technological return of DT operations at JET in support of ITER. This paper presents the progress since the start of the project in 2014 in the preparatory experiments, analyses and studies in the areas of neutronics, neutron induced activation and damage in ITER materials, nuclear safety, tritium retention, permeation and outgassing, and waste production in preparation of DTE2.
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| 38. |
- Battistoni, Giuseppe, et al.
(author)
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Applications of FLUKA Monte Carlo code for nuclear and accelerator physics
- 2011
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In: Nuclear Instruments and Methods in Physics Research Section B. - : Elsevier BV. - 0168-583X .- 1872-9584. ; 269:24, s. 2850-2856
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Journal article (peer-reviewed)abstract
- FLUKA is a general purpose Monte Carlo code capable of handling all radiation components from thermal energies (for neutrons) or 1 keV (for all other particles) to cosmic ray energies and can be applied in many different fields. Presently the code is maintained on Linux. The validity of the physical models implemented in FLUKA has been benchmarked against a variety of experimental data over a wide energy range, from accelerator data to cosmic ray showers in the Earth atmosphere. FLUKA is widely used for studies related both to basic research and to applications in particle accelerators, radiation protection and dosimetry, including the specific issue of radiation damage in space missions, radiobiology (including radiotherapy) and cosmic ray calculations.After a short description of the main features that make FLUKA valuable for these topics, the present paper summarizes some of the recent applications of the FLUKA Monte Carlo code in the nuclear as well high energy physics. In particular it addresses such topics as accelerator related applications.
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| 39. |
- Battistoni, Giuseppe, et al.
(author)
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The Application of the Monte Carlo Code FLUKA in Radiation Protection Studies for the Large Hadron Collider
- 2011
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Conference paper (peer-reviewed)abstract
- The multi-purpose particle interaction and transport code FLUKA is integral part of all radiation protection studies for the design and operation of the Large Hadron Collider (LHC) at CERN. It is one of the very few codes available for this type of calculations which is capable to calculate in one and the same simulation proton-proton and heavy ion collisions at LHC energies as well as the entire hadronic and electromagnetic particle cascade initiated by secondary particles in detectors and beam-line components from TeV energies down to energies of thermal neutrons. The present paper reviews these capabilities of FLUKA in sketching the relevant physics models along with examples ofradiation protection studies for the LHC such as shielding studies for underground areas occupied by personnel during LHC operation and the simulation of induced radioactivity around beam loss points. Integral part of the FLUKA development is a careful benchmarking of specific models as well as the code performance in actual, complex applications which is demonstrated with examples of studies relevant to radiation protection at the LHC.
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| 40. |
- Battistoni, G., et al.
(author)
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The FLUKA code and its use in hadron therapy
- 2008
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In: Nuovo Cimento della Societa Italiana di Fisica C. - Italian Physical Society. - 1124-1896. ; 31:1, s. 69-75
-
Journal article (peer-reviewed)abstract
- FLUKA is a multipurpose Monte Carto code describing transport and interaction with matter of a, large variety of particles over a wide energy range ill complex geometries. FLUKA is successfully applied ill several fields, including, but not only particle physics, cosmic-ray physics, dosimetry, radioprotection, hadron therapy. space radiation, accelerator design and neutronics. Here we briefly review recent model developments and provide examples of applications to hadron therapy, including calculation of physical and biological dose for comparison with analytical treatment planning engines as well as beta(+)-activation for therapy monitoring by means of positron emission tomography.
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| 41. |
- Murari, A., et al.
(author)
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Implementation and exploitation of JET enhancements at different fuel mixtures in preparation for DT operation and next step devices
- 2019
-
In: Fusion engineering and design. - : ELSEVIER SCIENCE SA. - 0920-3796 .- 1873-7196. ; 146, s. 741-744
-
Journal article (peer-reviewed)abstract
- In the framework of the ITER Physics Department of the EUROfusion Consortium, JET mission is focused on preparing for the next step devices by developing high performance scenarios and testing reactor relevant techniques and technologies. In terms of scenario development, a complete scan in isotopic composition has already started and, according to the present schedule, should include full T operation and culminate in a 50/50 DT campaign by 2020. In DD, significant increases in input power and various adjustments in fueling have allowed reaching the IPBp8(y,2) scaling up to 3 MA. A complete set of diagnostic upgrades is being implemented to support operation and to guarantee adequate scientific exploitation of the experiments. With regard to the technology, the main enhancements and specific tests are focused on maximizing the returns from the unprecedented 14 MeV neutron field and the tritium fuel cycle.
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| 42. |
- Pinsky, L., et al.
(author)
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Measurement of Fragmentation Products including Angular Distributions for 3, 5, and 10 GeV/A C and Si on several nuclear targets at the AGS
- 2010
-
In: 2009 12th International Conference on Nuclear Reaction Mechanisms, NRM 2009; Varenna; Italy; 15 June 2009 through 19 June 2009. - 2078-8835. - 9789290833413 ; 2, s. 431-437
-
Conference paper (peer-reviewed)abstract
- Motivated by differences in the predicted fragmentation of heavy ions at energies around 5 GeV/A as employed in the event generators used by the FLUKA Monte Carlo Code [1], a set of measurements were carried out at the AGS facility at the Brookhaven National Laboratory to determine as much information as possible about the cross sections to allow harmonization of those event generators for these incident lab energies. The FLUKA Code employs the RQMD event generator of Sorge [2] for heavy ion interactions starting at 100 MeV/A and extending into the region around 5 GeV/A. Above those energies the DPMJET code of Ranft and Roesler [3] is typically employed to simulate such interactions. The detailed predictions of these event generators had some disagreement in the vicinity of this crossover energy and in order to tune these codes to be in closer harmony at the transition, and of course to be simulating nature as closely as possible, data were taken at 3, 5 and 10 GeV/A with beams of Fe, Si and C on a variety of targets including C, A1. Fe and Cu. The Fe data have not been fully analyzed, but results from the C and Si beams are available and the forward fragment spectrum along with a measurement of the charged particle angular distribution in a set of Si strip detectors out to about 45 degrees in the lab are available. These include sufficient statistics to provide the charged particle distributions as a function of the major projectile fragment. The detectors used in this measurement were based on what were reasonably available to us, and as such were limited in capability, and required separate data acquisition systems. Nevertheless, spectra were obtained that should be sufficient to enable the harmonization of the event generator codes at the crossover energy. This paper discusses only the experimental results and not the impact of those results on the FLUKA code.
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| 43. |
- Battistoni, Giuseppe, et al.
(author)
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FLUKA Capabilities and CERN Applications for the Study of Radiation Damage to Electronics at High-Energy Hadron Accelerators
- 2011
-
Conference paper (peer-reviewed)abstract
- The assessment of radiation damage to electronics is a complex process and requires a detailed description of the full particle energy spectra, as well as a clear characterization of the quantities used to predict radiation damage. FLUKA, a multi-purpose particle interaction and transport code, is capable of calculating proton-proton and heavy ion collisions at LHC energies and beyond. It correctly describes the entire hadronic and electromagnetic particle cascade initiated by secondary particles from TeV energies down to thermal neutrons, and provides direct scoring capabilities essential to estimate in detail the possible risk of radiation damage to electronics. This paper presents the FLUKA capabilities for applications related to radiation damage to electronics, providing benchmarking examples and showing the practical applications of FLUKA at CERN facilities such as CNGS and LHC. Related applications range from the study of device effects, the detailed characterization of the radiation field and radiation monitor calibration, to the input requirements for important mitigation studies including shielding, relocation or other options.
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| 44. |
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| 45. |
- Franic, Iva, et al.
(author)
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Climate, host and geography shape insect and fungal communities of trees
- 2023
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In: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 13:1
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Journal article (peer-reviewed)abstract
- Non-native pests, climate change, and their interactions are likely to alter relationships between trees and tree-associated organisms with consequences for forest health. To understand and predict such changes, factors structuring tree-associated communities need to be determined. Here, we analysed the data consisting of records of insects and fungi collected from dormant twigs from 155 tree species at 51 botanical gardens or arboreta in 32 countries. Generalized dissimilarity models revealed similar relative importance of studied climatic, host-related and geographic factors on differences in tree-associated communities. Mean annual temperature, phylogenetic distance between hosts and geographic distance between locations were the major drivers of dissimilarities. The increasing importance of high temperatures on differences in studied communities indicate that climate change could affect tree-associated organisms directly and indirectly through host range shifts. Insect and fungal communities were more similar between closely related vs. distant hosts suggesting that host range shifts may facilitate the emergence of new pests. Moreover, dissimilarities among tree-associated communities increased with geographic distance indicating that human-mediated transport may serve as a pathway of the introductions of new pests. The results of this study highlight the need to limit the establishment of tree pests and increase the resilience of forest ecosystems to changes in climate.
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| 46. |
- Franic, Iva, et al.
(author)
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Worldwide diversity of endophytic fungi and insects associated with dormant tree twigs
- 2022
-
In: Scientific Data. - : Nature Publishing Group. - 2052-4463. ; 9:1
-
Journal article (peer-reviewed)abstract
- International trade in plants and climate change are two of the main factors causing damaging tree pests (i.e. fungi and insects) to spread into new areas. To mitigate these risks, a large-scale assessment of tree-associated fungi and insects is needed. We present records of endophytic fungi and insects in twigs of 17 angiosperm and gymnosperm genera, from 51 locations in 32 countries worldwide. Endophytic fungi were characterized by high-throughput sequencing of 352 samples from 145 tree species in 28 countries. Insects were reared from 227 samples of 109 tree species in 18 countries and sorted into taxonomic orders and feeding guilds. Herbivorous insects were grouped into morphospecies and were identified using molecular and morphological approaches. This dataset reveals the diversity of tree-associated taxa, as it contains 12,721 fungal Amplicon Sequence Variants and 208 herbivorous insect morphospecies, sampled across broad geographic and climatic gradients and for many tree species. This dataset will facilitate applied and fundamental studies on the distribution of fungal endophytes and insects in trees.
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| 47. |
- López-Goldar, Xosé, et al.
(author)
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Genetic variation in the constitutive defensive metabolome and its inducibility are geographically structured and largely determined by demographic processes in maritime pine
- 2019
-
In: Journal of Ecology. - : Blackwell Publishing Ltd. - 0022-0477 .- 1365-2745. ; 107:5, s. 2464-2477
-
Journal article (peer-reviewed)abstract
- Interspecific phenotypic variation in plant secondary metabolites (PSM) is often explained by biotic and abiotic factors. However, patterns of variation within species do not clearly fit the theoretical predictions. Exploring how genetics, environment and demographic processes shape such variation among and within populations is crucial for understanding evolution of PSM, particularly in long-lived plants such as forest trees. Here, we quantified genetic variation in PSM among and within populations, and explored drivers of local adaptation by studying the role of climate as a source of population differentiation in PSM of maritime pine. Constitutive profile and concentrations of 63 PSM and their herbivory-associated inducibility were determined in the bark of 130 clonally replicated genotypes with known familial structure from 10 populations covering the distribution range of the species. We compared neutral and quantitative population genetic differentiation of PSM (F ST and Q ST ). Also, we accounted for population genetic structure and kinship among individuals when exploring climate–trait relationships. We found large population differentiation and additive genetic variation in constitutive PSM. Many PSM were inducible, although very low genetic variation was observed with respect to their inducibility. Q ST –F ST comparisons suggest that differentiation of most diterpenes, monoterpenes, and phenolics can be explained by neutral demographic processes. Spatially heterogeneous selection across populations leading to local adaptation was only found for total constitutive sesquiterpenes and a few individual PSM. After accounting for population genetic structure, only the constitutive concentration of two sesquiterpenes showing signs of diversifying selection was predicted by climate, with decreasing concentrations along a growth-prone climatic gradient. Synthesis. Evolutionary patterns of plant secondary metabolites depended on their chemical nature, with neutral differentiation governing most plant secondary metabolites. Evidence of local adaptation was only found for total constitutive sesquiterpenes and a few individual plant secondary metabolites. The low genetic variation in the inducibility of plant secondary metabolites suggests a conserved model of defensive induction in this species. Since population differentiation linked to past demographic history could lead to false positives of adaptive differentiation signals, accounting for the genetic relatedness among populations is required to infer the environmental determinants of intraspecific genetic variation in putatively adaptive traits such as plant defences.
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| 48. |
- Moro, F., et al.
(author)
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Neutronic calculations in support of the design of the ITER High Resolution Neutron Spectrometer
- 2011
-
In: Fusion engineering and design. - : Elsevier BV. - 0920-3796 .- 1873-7196. ; 86:6-8, s. 1277-1281
-
Journal article (peer-reviewed)abstract
- This paper presents the results of neutronic calculations performed to address important issues related to the optimization of the ITER HRNS (High resolution Neutron Spectrometer) design, in particular concerning the definition of the collimator and the choice of the detector system. The calculations have been carried out using the MCNP5 Monte Carlo code in a full 3-D geometry. The HRNS collimation system has been included in the latest MCNP ITER 40 model (Alite-4). The ITER scenario 2 reference DT plasma fusion neutron source peaked at 14.1 MeV with Gaussian energy distribution has been used. Neutron fluxes and energy spectra (>1 MeV) have been evaluated at different positions along the HRNS collimator and at the detector location. The noise-to-signal ratio (i.e. the ratio of collided to uncoilided neutrons), the breakdown of the collided spectrum into its components, the dependency on the first wall aperture and the gamma-ray spectra at the detector position have also been analyzed. The impact of the results on the design of the HRNS diagnostic system is discussed.
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| 49. |
- Moro, Fabio, et al.
(author)
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Nuclear analysis of the ITER radial neutron camera architectural options
- 2017
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In: Fusion engineering and design. - : ELSEVIER SCIENCE SA. - 0920-3796 .- 1873-7196. ; 123, s. 1033-1038
-
Journal article (peer-reviewed)abstract
- The ITER Radial Neutron Camera (RNC) is a multichannel detection system hosted in the Equatorial Port Plug 1 (EPP 1) designed to provide information on the neutron source total strength arid emissivity profiles. It consists of two sub-systems: the ex-port line-of-sights (LOSs), covering the plasma core, embedded in a massive shielding block located in the Port Interspace, and the in-port LOSs distributed in two removable cassettes integrated inside the Port Plug. Presently, the RNC layout development process is undergoing a System Level Design phase: several preliminary architectural options based on a System Engineering work have been defined: a detailed nuclear analysis of these options has been performed through radiation transport calculations with the MCNP Monte Carlo code. The radiation environment at the detectors positions has been fully characterized through the evaluation of the expected neutron spectra and the secondary gamma background and the analysis of the 3D radiation maps. MoreOver, the impact of a reduced ex-port shielding block on the neutron and gamma spectra has been investigated. The results of the present study provide guidelines for the development of the RNC final design and the necessary data for the measurement performance analysis.
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| 50. |
- Villari, R., et al.
(author)
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ITER oriented neutronics benchmark experiments on neutron streaming and shutdown dose rate at JET
- 2017
-
In: Fusion engineering and design. - : ELSEVIER SCIENCE SA. - 0920-3796 .- 1873-7196. ; 123, s. 171-176
-
Journal article (peer-reviewed)abstract
- Neutronics benchmark experiments are conducted at JET in the frame of WPJET3 NEXP within EUROfusion Consortium for validating the neutronics codes and tools used in ITER nuclear analyses to predict quantities such as the neutron flux along streaming paths and dose rates at the shutdown due to activated components. The preparation of neutron streaming and shutdown dose rate experiments for the future Deuterium-Tritium operations (DTE2 campaign) are in progress. This paper summarizes the status of measurements and analyses in progress in the current Deuterium-Deuterium (DD) campaign and the efforts in preparation for DTE2.
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