scholarly journals JASPER: a software for quantum chromodynamics Dyson-Schwinger equation numerical calculation

2021 ◽  
Vol 2094 (3) ◽  
pp. 032027
Author(s):  
K M Semenov-Tian-Shansky ◽  
D A Vokhmintsev
Keyword(s):  
Quantum Chromodynamics ◽  
Nuclear Physics ◽  
High Performance ◽  
Numerical Algorithms ◽  
Quark Propagator ◽  
Strong Coupling Regime ◽  
Physics Institute ◽  
Particle Properties ◽  
Complex Euclidean Space ◽  
Dynamical Quark Mass

Abstract The JASPER program is the first part of the high-performance computing information system for estimate some elementary particle properties, developing at Petersburg Nuclear Physics Institute. The JASPER is an implementation of the Dyson-Schwinger equation numerical solution for simple dressed quark propagator calculation in rainbow approximation. The Dyson-Schwinger equation solution with the Marice-Tandy Ansatz is one of several phenomenological approaches to obtain quantitative results in quantum chromodynamics (QCD) within strong coupling regime. The JASPER program is programmed in the C++ language and uses the numerical algorithms from the GNU Scientific Library (GSL). The numerical results for dynamical quark mass in complex Euclidean space were obtained. This result will be employed to study the hadron spectrum with the Bethe-Salpeter equation approach.

scholarly journals Characterization of Highly Irradiated ALPIDE Silicon Sensors

Universe ◽  
2019 ◽  
Vol 5 (4) ◽  
pp. 91
Author(s):  
Valentina Raskina ◽  
Filip Křížek
Keyword(s):  
Nuclear Physics ◽  
Detection Efficiency ◽  
Tracking System ◽  
Physics Institute ◽  
Total Ionization ◽  
Silicon Sensors ◽  
Active Pixel ◽  
Academy Of Sciences

The ALICE (A Large Ion Collider Experiment) experiment at CERN will upgrade its Inner Tracking System (ITS) detector. The new ITS will consist of seven coaxial cylindrical layers of ALPIDE silicon sensors which are based on Monolithic Active Pixel Sensor (MAPS) technology. We have studied the radiation hardness of ALPIDE sensors using a 30 MeV proton beam provided by the cyclotron U-120M of the Nuclear Physics Institute of the Czech Academy of Sciences in Řež. In this paper, these long-term measurements will be described. After being irradiated up to the total ionization dose 2.7 Mrad and non-ionizing energy loss 2.7 × 10 13 1 MeV n eq · cm - 2 , ALPIDE sensors fulfill ITS upgrade project technical design requirements in terms of detection efficiency and fake-hit rate.

scholarly journals Numerical algorithms for high-performance computational science

2020 ◽  
Vol 378 (2166) ◽  
pp. 20190066 ◽  
Author(s):  
Jack Dongarra ◽  
Laura Grigori ◽  
Nicholas J. Higham
Keyword(s):  
High Performance ◽  
Numerical Algorithms ◽  
Computational Science ◽  
Floating Point ◽  
Important Criterion ◽  
Data Movement ◽  
Floating Point Arithmetic ◽  
High Performance Computers ◽  
Point Arithmetic ◽  
Speed And Accuracy

A number of features of today’s high-performance computers make it challenging to exploit these machines fully for computational science. These include increasing core counts but stagnant clock frequencies; the high cost of data movement; use of accelerators (GPUs, FPGAs, coprocessors), making architectures increasingly heterogeneous; and multi- ple precisions of floating-point arithmetic, including half-precision. Moreover, as well as maximizing speed and accuracy, minimizing energy consumption is an important criterion. New generations of algorithms are needed to tackle these challenges. We discuss some approaches that we can take to develop numerical algorithms for high-performance computational science, with a view to exploiting the next generation of supercomputers. This article is part of a discussion meeting issue ‘Numerical algorithms for high-performance computational science’.

Adaptive Precision Block-Jacobi for High Performance Preconditioning in the Ginkgo Linear Algebra Software

2021 ◽  
Vol 47 (2) ◽  
pp. 1-28
Author(s):  
Goran Flegar ◽  
Hartwig Anzt ◽  
Terry Cojean ◽  
Enrique S. Quintana-Ortí
Keyword(s):  
Linear Algebra ◽  
Graphics Processing Units ◽  
High Performance ◽  
Numerical Algorithms ◽  
Mixed Precision ◽  
Before And After ◽  
Memory Accesses ◽  
Specialized Hardware ◽  
The Individual ◽  
Graphics Processing

The use of mixed precision in numerical algorithms is a promising strategy for accelerating scientific applications. In particular, the adoption of specialized hardware and data formats for low-precision arithmetic in high-end GPUs (graphics processing units) has motivated numerous efforts aiming at carefully reducing the working precision in order to speed up the computations. For algorithms whose performance is bound by the memory bandwidth, the idea of compressing its data before (and after) memory accesses has received considerable attention. One idea is to store an approximate operator–like a preconditioner–in lower than working precision hopefully without impacting the algorithm output. We realize the first high-performance implementation of an adaptive precision block-Jacobi preconditioner which selects the precision format used to store the preconditioner data on-the-fly, taking into account the numerical properties of the individual preconditioner blocks. We implement the adaptive block-Jacobi preconditioner as production-ready functionality in the Ginkgo linear algebra library, considering not only the precision formats that are part of the IEEE standard, but also customized formats which optimize the length of the exponent and significand to the characteristics of the preconditioner blocks. Experiments run on a state-of-the-art GPU accelerator show that our implementation offers attractive runtime savings.

Flood Inundation Prediction

2021 ◽  
Vol 54 (1) ◽  
Author(s):  
Paul D. Bates
Keyword(s):  
Fluid Mechanics ◽  
Land Surface ◽  
High Performance ◽  
Numerical Algorithms ◽  
Economic Damage ◽  
Annual Review ◽  
Publication Date ◽  
Flood Inundation ◽  
Damage Mapping ◽  
Performance Computing

Every year flood events lead to thousands of casualties and significant economic damage. Mapping the areas at risk of flooding is critical to reducing these losses, yet until the last few years such information was available for only a handful of well-studied locations. This review surveys recent progress to address this fundamental issue through a novel combination of appropriate physics, efficient numerical algorithms, high-performance computing, new sources of big data, and model automation frameworks. The review describes the fluid mechanics of inundation and the models used to predict it, before going on to consider the developments that have led in the last five years to the creation of the first true fluid mechanics models of flooding over the entire terrestrial land surface. Expected final online publication date for the Annual Review of Fluid Mechanics, Volume 54 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

scholarly journals Quantum Chromodynamics and Nuclear Physics at Extreme Energy Density

2005 ◽  
Author(s):  
B. Mueller ◽  
S.A. Bass ◽  
S. Chandrasekharan ◽  
T. Mehen ◽  
R.P. Springer
Keyword(s):  
Energy Density ◽  
Quantum Chromodynamics ◽  
Nuclear Physics

scholarly journals Efficient finite element hyperelasticity solver for blood vessel simulations

2020 ◽  
Vol 14 ◽  
pp. 174830262093101
Author(s):  
Xinhong Wang ◽  
Zhengzheng Yan ◽  
Yi Jiang ◽  
Rongliang Chen
Keyword(s):  
Finite Element ◽  
Blood Vessel ◽  
Blood Vessels ◽  
High Performance ◽  
Soft Tissues ◽  
Circulatory System ◽  
Numerical Algorithms ◽  
External Pressure ◽  
Patient Specific ◽  
Schwarz Method

The blood vessels play a key role in the human circulatory system. As a tremendous amount of efforts have been devoted to develop mathematical models for investigating the elastic behaviors of human blood vessels, high performance numerical algorithms aiming at solving these models have attracted attention. In this work, we present an efficient finite element solver for an elastodynamic model which is commonly used for simulating soft tissues under external pressure loadings. In particular, the elastic material is assumed to satisfy the Saint–Venant–Kirchhoff law, the governing equation is spatially discretized by a finite element method, and a fully implicit backward difference method is used for the temporal discretization. The resulting nonlinear system is then solved by a Newton–Krylov–Schwarz method. It is the first time to apply the Newton–Krylov–Schwarz method to the Saint–Venant–Kirchhoff model for a patient-specific blood vessel. Numerical tests verify the efficiency of the proposed method and demonstrate its capability for bioengineering applications.

scholarly journals Performance and application of heavy ion nuclear microbeam facility at the Nuclear Physics Institute in Řež, Czech Republic

2019 ◽  
Vol 90 (1) ◽  
pp. 013701 ◽  
Author(s):  
Oleksandr Romanenko ◽  
Vladimir Havranek ◽  
Anna Mackova ◽  
Marie Davidkova ◽  
Mariapompea Cutroneo ◽  
...  
Keyword(s):  
Czech Republic ◽  
Nuclear Physics ◽  
Heavy Ion ◽  
Physics Institute ◽  
Nuclear Physics Institute

scholarly journals High-power TR-24 cyclotron-based p-n convertor cooled by submerged orifice jet

2020 ◽  
Vol 231 ◽  
pp. 03005
Author(s):  
Bém Pavel ◽  
Běhal Radomír ◽  
Gӧtz Miloslav ◽  
Plíhal Petr ◽  
Poklop Dušan ◽  
...  
Keyword(s):  
Nuclear Physics ◽  
Cooling System ◽  
Forward Direction ◽  
Beam Current ◽  
Neutron Field ◽  
Physics Institute ◽  
Jet Cooling ◽  
Submerged Orifice ◽  
Target Output ◽  
Nuclear Physics Institute

The TR-24 cyclotron (Advanced Cyclotron Systems Inc., Canada) of the Nuclear Physics Institute in Řež provides protons with variable energies from 18 MeV up to 24 MeV and beam current of 0.3 mA. For such parameters, the p +Be source reaction on thick Be target can produce a white-spectrum neutron field (En ≤ 22 MeV) with the intensity of 5×10 12 n/s/sr in forward direction. Present paper outlines the development of Be-target cooling system, devoted to remove the heat load of 7 kW (density up to 4 kW/cm2) from the target. Due to novel “orifice-form“ of jet cooling (resulting in the shortest source-to- sample distance of 20 mm) with extremely high cooling efficiency, the TR-24 p-n convertor can achieve neutron-flux up to 2×1012n/cm2/s nearby the target output.

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