Suchergebnisse

Are you for or against nuclear energy? The necessity to respond to climate change has put nuclear energy back on the politial agenda as an alternative energy source. This is part of approaches to 'decarbonise' energy through a shift from coal to natural gas, nuclear energy and renewables. Yet, the recourse to nuclear energy is hotly debated. Opponents are rife, as you are supporter. Can you adopt each position in turn? This unit challenges you to do so.

High pressure xenon Time Projection Chambers (TPC) based on secondary scintillation (electroluminescence) signal amplification are being proposed for rare event detection such as directional dark matter, double electron capture and double beta decay detection. The discrimination of the rare event through the topological signature of primary ionisation trails is a major asset for this type of TPC when compared to single liquid or double-phase TPCs, limited mainly by the high electron diffusion in pure xenon. Helium admixtures with xenon can be an attractive solution to reduce the electron diffu- sion significantly, improving the discrimination efficiency of these optical TPCs. We have measured the electroluminescence (EL) yield of Xe–He mixtures, in the range of 0 to 30% He and demonstrated the small impact on the EL yield of the addition of helium to pure xenon. For a typical reduced electric field of 2.5 kV/cm/bar in the EL region, the EL yield is lowered by ∼ 2%, 3%, 6% and 10% for 10%, 15%, 20% and 30% of helium concentration, respectively. This decrease is less than what has been obtained from the most recent simulation framework in the literature. The impact of the addition of helium on EL statistical fluctuations is negligible, within the experimental uncertainties. The present results are an important benchmark for the simulation tools to be applied to future optical TPCs based on Xe-He mixtures ; The NEXT Collaboration acknowledges support from the following agencies and institutions: the European Research Council (ERC) under the Advanced Grant 339787- NEXT; the European Union's Framework Programme for Research and Innovation Horizon 2020 (2014-2020) under the Marie Sklodowska-Curie Grant Agreements No. 674896, 690575 and 740055; the Ministerio de Econom´ıa y Competitividad of Spain under grants FIS2014- 53371-C04, RTI2018-095979, the Severo Ochoa Program SEV-2014-0398 and the Mar´ıa de Maetzu Program MDM-2016-0692; the GVA of Spain under grants PROMETEO/2016/120 and SEJI/2017/011; the Portuguese FCT ...

In this work, we will explore the feasibility of porting a Particle-in-cell code (EUTERPE) to an ARM multi-core platform from the Mont-Blanc project. The used prototype is based on a system-on-chip Samsung Exynos 5 with an integrated GPU. It is the first prototype that could be used for High-Performance Computing (HPC), since it supports double precision and parallel programming languages. ; The research leading to these results has received funding from the European Com- munity's Seventh Framework Programme (FP7/2007-2013) under the Mont-Blanc Project (http://www.montblanc-project.eu), grant agreement no 288777. This work was supported in part by grant ENE2012-30832, Ministerio de Economía y Competitividad and carried out within the framework of the EUROfusion Consortium, receiving funding from the European Union's Horizon 2020 research and innovation programme under grant agreement number 633053. The views and opinions expressed herein do not necessarily reect those of the European Commission. ; Peer Reviewed ; Postprint (published version)

In this work, we will explore the feasibility of porting a Particle-in-cell code (EUTERPE) to an ARM multi-core platform from the Mont-Blanc project. The used prototype is based on a system-on-chip Samsung Exynos 5 with an integrated GPU. It is the first prototype that could be used for High-Performance Computing (HPC), since it supports double precision and parallel programming languages. ; The research leading to these results has received funding from the European Com- munity's Seventh Framework Programme (FP7/2007-2013) under the Mont-Blanc Project (http://www.montblanc-project.eu), grant agreement no 288777. This work was supported in part by grant ENE2012-30832, Ministerio de Economía y Competitividad and carried out within the framework of the EUROfusion Consortium, receiving funding from the European Union's Horizon 2020 research and innovation programme under grant agreement number 633053. The views and opinions expressed herein do not necessarily reect those of the European Commission. ; Peer Reviewed ; Postprint (published version)

In this paper we consider conformal dynamics for a system of N interacting relativistic massless particles. A detailed study is done for the case of two particles, with a particular attention to the symmetries of the problem. In fact, we show that this analysis could be extended to the case of higher spin symmetries. Always in the two-particle case a formulation in terms of bilocal fields is proposed. For a system of N particles we consider two possible scenarios: (i) the action is invariant under any permutation of the N particles. This case corresponds to completely democratic interactions with each particle interacting with all the others. The action depends on N − 1 dimensionless coupling constants. (ii) By putting the particles along a one-dimensional lattice (open or closed) with nearest neighbor interactions, one obtains a model with only two-body interactions depending on a single dimensionless coupling. This model can be easily extended to the continuum case, obtaining a conformal stringlike (closed or open) system.

Convolutional neural networks (CNNs) are widely used state-of-the-art computer vision tools that are becoming increasingly popular in high-energy physics. In this paper, we attempt to understand the potential of CNNs for event classification in the NEXT experiment, which will search for neutrinoless double-beta decay in 136Xe. To do so, we demonstrate the usage of CNNs for the identification of electron-positron pair production events, which exhibit a topology similar to that of a neutrinoless double-beta decay event. These events were produced in the NEXT-White high-pressure xenon TPC using 2.6 MeV gamma rays from a 228Th calibration source. We train a network on Monte Carlo-simulated events and show that, by applying on-the-fly data augmentation, the network can be made robust against differences between simulation and data. The use of CNNs offers significant improvement in signal efficiency and background rejection when compared to previous non-CNN-based analyses ; This study used computing resources from Artemisa, co-funded by the European Union through the 2014-2020 FEDER Operative Programme of the Comunitat Valenciana, project DIFEDER/2018/048. This research used resources of the Argonne Leadership Computing Facility, which is a DOE Office of Science User Facility supported under Contract DE-AC02-06CH11357. The NEXT collaboration acknowledges support from the following agencies and institutions: Xunta de Galicia (Centro singularde investigación de Galicia accreditation 2019-2022), by European Union ERDF, and by the "María de Maeztu" Units of Excellence program MDM-2016-0692 and the Spanish Research State Agency"; the European Research Council (ERC) under the Advanced Grant 339787-NEXT; the European Union's Framework Programme for Research and Innovation Horizon 2020 (2014-2020) under the Grant Agreements No. 674896, 690575 and 740055; the Ministerio de Economía y Competitividad and the Ministerio de Ciencia, Innovación y Universidades of Spain under grants FIS2014-53371-C04, RTI2018-095979, the Severo ...

The problem of confining a plasma, with sufficiently high density and temperature, is of crucial importance if nuclear fusion is to be made usable as a form of power generation. Tokamaks - devices with a toroidal geometry - are among the most popular candidates by which such confinement can be achieved. A tokamak separates a plasma from its surroundings by means of a magnetic field generated by several coils distributed around the plasma. The main topic of Magnetic Control of Tokamak Plasmas is the design of feedback control systems guaranteeing the stability of plasma equilibrium inside a tokamak and the regulation of the plasma position and shape during plasma pulses. Modelling and control details are presented, allowing the non-expert to understand the control problem. Starting from equations of magneto-hydro-dynamics, all the steps needed for the derivation of plasma state-space models are enumerated. The basics of electromagnetics are frequently recalled. The control problem is then described beginning with control of current and position - vertical and radial - and progressing to the more challenging shape control. The solutions proposed vary from simple PIDs to more sophisticated MIMO controllers. Wherever possible, the various topics are rounded out with results obtained through the authors' contributions to experiments with actual tokamaks. Mathematical details which are outside the normal province of control engineers are presented in an appendix for the interested reader. The ideas formulated in this monograph will be of great practical help to control engineers, academic researchers and graduate students working directly with problems related to the control of nuclear fusion. They will also stimulate control researchers interested more generally in the advanced applications of the discipline.

I outline the first steps in the process of describing nuclear ground states with an expansion around two-body unitarity. At leading order, the effective field theory displays discrete scale invariance with a single dimensionful parameter, which determines all ground-state and low-lying excitation energies. Sub-leading corrections are smaller and perturbative. Results for light nuclei, large bosonic clusters at unitarity, and nuclear matter are reported. ; U.S. Department of Energy, Office of Science, Office of Nuclear Physics [DE-FG02-04ER41338]; European Union Research and Innovation program Horizon 2020 [654002] ; Open access journal ; This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.

Real-time data processing is one of the central processes of particle physics experiments which require large computing resources. The LHCb (Large Hadron Collider beauty) experiment will be upgraded to cope with a particle bunch collision rate of 30 million times per second, producing 10 9 particles/s. 40 Tbits/s need to be processed in real-time to make filtering decisions to store data. This poses a computing challenge that requires exploration of modern hardware and software solutions. We present Compass, a particle tracking algorithm and a parallel raw input decoding optimized for GPUs. It is designed for highly parallel architectures, data-oriented, and optimized for fast and localized data access. Our algorithm is configurable, and we explore the trade-off in computing and physics performance of various configurations. A CPU implementation that delivers the same physics performance as our GPU implementation is presented. We discuss the achieved physics performance and validate it with Monte Carlo simulated data. We show a computing performance analysis comparing consumer and server-grade GPUs, and a CPU. We show the feasibility of using a full GPU decoding and particle tracking algorithm for high-throughput particle trajectories reconstruction, where our algorithm improves the throughput up to 7.4 × compared to the LHCb baseline. ; This work was supported in part by the European Research Council (ERC) under the European Union's Horizon 2020 Research and Innovation Programme under Grant 724777 ``RECEPT,'' and in part by the Spanish MINISTERIO DE ECONOMÍA Y COMPETITIVIDAD though Project Grant TIN2016-79637-P TOWARDS UNIFICATION OF HPC AND BIG DATA PARADIGMS.

In this short review paper I will draw attention to the most important steps made in the past decade toward a better understanding of the physics governing our Universe. The results that I will discuss are drawn from the photonic astrophysics, particle astrophysics, and neutrino astrophysics, which constitute the main tools for exploring the Universe. The union of these three tools has given rise to a new field of physics known as Astroparticle Physics. Because of the limited length of this paper, I have selected only a few arguments that, in my opinion, have been crucial for the progress of Physics.

AbstractCurrent science policy emphasizes practical outcomes. In this article, I explore how a fundamental research community addresses the value of research, an area that has received a little attention. In the wake of the discovery of the Higgs boson, I analyse how particle physicists interpret the values of their research in interviews and a strategic document. The result indicates a hierarchy of interests that coordinates different values of particle physics in discourse: the status of scientific and cultural value is higher than that of societal and material value. This finding implies that value propositions are inseparable from the articulation of interests, and qualitative discourse analysis can approach a combined understanding of the two. In science policy studies, there is not yet sufficient studies on how scientists appraise different values of research. The hierarchical discursive practice on values shed lights on a culture different from policy trends.