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Related papers: Vacuum Technology for Ion Sources

200 papers

In order to find the equilibrium geometries of molecules and solids and to perform ab initio molecular dynamics, it is necessary to calculate the forces on the nuclei. We present a correlated sampling method to efficiently calculate…

Condensed Matter · Physics 2009-10-31 Claudia Filippi , C. J. Umrigar

The Future Circular Collider (FCC), currently in the design phase, will address many outstanding questions in particle physics. The technology to succeed in this 100 km circumference collider goes beyond present limits. Ultra-high vacuum…

Accelerator Physics · Physics 2017-09-28 Ida Aichinger , Roberto Kersevan , Paolo Chiggiato

Notions of invariance pressure for control systems are introduced based on weights for the control values. The equivalence is shown between inner invariance pressure based on spanning sets of controls and on invariant open covers,…

Optimization and Control · Mathematics 2018-04-17 Fritz Colonius , Alexandre J. Santana , João A. N. Cossich

In this paper, four distinct approaches to Volume of Fluid (VOF) computational method are compared. Two of the methods are the 'simplified' VOF formulations, in that they do not require geometrical interface reconstruction. The assessment…

Computational Physics · Physics 2014-05-21 Wojciech Aniszewski , Thibaut Ménard , Maciej Marek

Detailed numerical results obtained with state-of-the-art Quantum Monte Carlo (QMC) simulations are presented for the superfluid phase of $^4$He at saturated vapor pressure. The aim of this contribution is that of providing reliable,…

Statistical Mechanics · Physics 2026-05-04 Massimo Boninsegni

We introduce an efficient scheme for the molecular dynamics of electronic systems by means of quantum Monte Carlo. The evaluation of the (Born-Oppenheimer) forces acting on the ionic positions is achieved by two main ingredients: i) the…

Strongly Correlated Electrons · Physics 2009-11-13 Claudio Attaccalite , Sandro Sorella

The ground-state properties of two-dimensional liquid $^4$He at zero temperature are studied by means of a quadratic diffusion Monte Carlo method. As interatomic potential we use a revised version of the HFDHE2 Aziz potential which is…

Condensed Matter · Physics 2009-10-28 S. Giorgini , J. Boronat , J. Casulleras

Radiative pressure exerted by line interactions is a prominent driver of outflows in astrophysical systems, being at work in the outflows emerging from hot stars or from the accretion discs of cataclysmic variables, massive young stars and…

Solar and Stellar Astrophysics · Physics 2015-09-29 U. M. Noebauer , S. A. Sim

We present a comprehensive benchmark study of the adsorption energy of a single water molecule on the (001) LiH surface using periodic coupled cluster and quantum Monte Carlo theories. We benchmark and compare different implementations of…

Monte Carlo techniques play a central role in statistical mechanics approaches for connecting macroscopic thermodynamic and kinetic properties to the electronic structure of a material. This paper describes the implementation of Monte Carlo…

Materials Science · Physics 2023-09-22 Brian Puchala , John C. Thomas , Anton Van der Ven

The present letter describes an atomic scale investigation of a chemical reaction for selective hydrogen production. This clean fuel is a sustainable energy source. Because electron transfer is the key to such reactions, accurate methods…

Chemical Physics · Physics 2019-08-29 Rajesh O. Sharma , Tapio Rantala , Philip E Hoggan

The decay rate of a metastable vacuum is usually calculated using a semiclassical approximation to the Euclidean path integral. The extension to a complete Euclidean lattice Monte Carlo computation, however, is hampered by analytic…

High Energy Physics - Lattice · Physics 2023-05-30 Jiayu Shen , Patrick Draper , Aida X. El-Khadra

Phonon Monte Carlo (PMC) is a versatile stochasic technique for solving the Boltzmann transport equation for phonons. It is particularly well suited for analyzing thermal transport in structures that have real-space roughness or are too…

Mesoscale and Nanoscale Physics · Physics 2016-02-26 L. N. Maurer , S. Mei , I. Knezevic

This study presents a novel pressure-based methodology for the efficient numerical solution of a four-equation two-phase diffuse interface model. The proposed methodology has the potential to simulate low-Mach flows with mass transfer. In…

Fluid Dynamics · Physics 2021-10-12 Andreas D. Demou , Nicoló Scapin , Marica Pelanti , Luca Brandt

We investigate Monte Carlo energy and variance minimization techniques for optimizing many-body wave functions. Several variants of the basic techniques are studied, including limiting the variations in the weighting factors which arise in…

Condensed Matter · Physics 2009-10-31 P. R. C. Kent , R. J. Needs , G. Rajagopal

New hybrid Molecular Dynamics-Monte Carlo methods are proposed to increase the efficiency of constant-pressure simulations. Two variations of the isobaric Molecular Dynamics component of the algorithms are considered. In the first, we use…

Soft Condensed Matter · Physics 2009-11-07 Roland Faller , Juan J. de Pablo

Droplet nucleation and evaporation are ubiquitous in nature and many technological applications, such as phase-change cooling and boiling heat transfer. So far, the description of these phenomena at the molecular scale has posed challenges…

Fluid Dynamics · Physics 2023-11-28 Panagiotis E. Theodorakis , Y. Wang , A. Chen , B. Liu

This paper introduces quantum computing methods for Monte Carlo simulations in power systems which are expected to be exponentially faster than their classical computing counterparts. Monte Carlo simulations is a fundamental method, widely…

Quantum Physics · Physics 2023-10-02 Emilie Jong , Brynjar Sævarsson , Hjörtur Jóhannsson , Spyros Chatzivasileiadis

Nowadays, there is pressing demand for sustainable energy sources, or clean and 'green' fuel and hydrogen is a perfect candidate. It can be made by dissociating methane with the energy input compensated by metal-hydrogen bond formation.…

Chemical Physics · Physics 2022-06-22 Philip E. Hoggan

Monte Carlo methods play important part in modern statistical physics. The application of these methods suffer from two main difficulties.The first is caused by the relatively small number of particles that can participate in any numerical…

Statistical Mechanics · Physics 2007-05-23 A. Brandt , V. Ilyin