Neutron diffraction study of quantum effects on the pair correlation function of low-density 4 He

2002 ◽  
Vol 74 (0) ◽  
pp. s418-s420 ◽  
Author(s):  
E. Guarini ◽  
F. Barocchi ◽  
M. Celli ◽  
H.E. Fischer ◽  
R. Magli ◽  
...  
Keyword(s):  
Correlation Function ◽  
Neutron Diffraction ◽  
Diffraction Study ◽  
Pair Correlation Function ◽  
Pair Correlation ◽  
Quantum Effects ◽  
Neutron Diffraction Study ◽  
Low Density

On the pair correlation function for hard spheres at low density and temperature

1968 ◽  
Vol 46 (7) ◽  
pp. 879-888 ◽  
Author(s):  
M. S. Miller ◽  
J. D. Poll
Keyword(s):  
Correlation Function ◽  
Pair Correlation Function ◽  
Hard Spheres ◽  
Pair Correlation ◽  
Quantum Mechanical Calculation ◽  
Quantum Mechanical ◽  
Low Density ◽  
Free Particles ◽  
Low Density Limit ◽  
Hard Sphere Diameters

A quantum-mechanical calculation of the pair correlation function for hard spheres in the low-density limit has been made. This calculation is, therefore, valid at low temperatures, where quantum-mechanical diffraction and symmetry effects are important. Results are given for various temperatures and hard-sphere diameters. The pair correlation function is presented in the form g = gB + gS, where gB is the correlation function for Boltzmann particles and gS describes the symmetry effects. It is found that gS(R) for any value of the separation R is always smaller than the corresponding value for free particles.

DISSIPATIVE PROCESSES IN LOW DENSITY STRONGLY INTERACTING 2D ELECTRON SYSTEMS

2010 ◽  
Vol 24 (25n26) ◽  
pp. 4946-4960
Author(s):  
DAVID NEILSON
Keyword(s):  
Correlation Function ◽  
Pair Correlation Function ◽  
Mode Coupling ◽  
Glassy Phase ◽  
Pair Correlation ◽  
Low Density ◽  
Electron Systems ◽  
Electron Correlations ◽  
Electron Densities ◽  
Theoretical Approaches

A glassy phase in disordered two dimensional (2D) electron systems may exist at low temperatures for electron densities lying intermediate between the Fermi liquid and Wigner crystal limits. The glassy phase is generated by the combined effects of disorder and the strong electron-electron correlations arising from the repulsive Coulomb interactions. Our approach here is motivated by the observation that at low electron densities the electron pair correlation function, as numerically determined for a non-disordered 2D system from Monte Carlo simulations, is very similar to the pair correlation function for a 2D classical system of hard discs. This suggests that theoretical approaches to 2D classical systems of hard discs may be of use in studying the disordered, low density electron problem. We use this picture to study its dynamics on the electron-liquid side of a glass transition. At long times the major relaxation process in the electron-liquid will be a rearrangement of increasingly large groups of the discs, rather than the movement of the discs separately. Such systems have been studied numerically and they display all the characteristics of glassy behaviour. There is a slowing down of the dynamics and a limiting value of the retarded spatial correlations. Motivated by the success of mode-coupling theories for hard spheres and discs in reproducing experimental results in classical fluids, we use the Mori formalism within a mode-coupling theory to obtain semi-quantitative insight into the role of electron correlations as they affect the time response of the weakly disordered 2D electron system at low densities.

Neutron Diffraction Study on Partial Pair Correlation Functions of Water at Ambient Temperature

2018 ◽  
Vol 91 (11) ◽  
pp. 1586-1595 ◽  
Author(s):  
Yasuo Kameda ◽  
Yuko Amo ◽  
Takeshi Usuki ◽  
Yasuhiro Umebayashi ◽  
Kazutaka Ikeda ◽  
...  
Keyword(s):  
Neutron Diffraction ◽  
Ambient Temperature ◽  
Diffraction Study ◽  
Correlation Functions ◽  
Pair Correlation ◽  
Neutron Diffraction Study ◽  
Pair Correlation Functions

Alternative materials for radiovoltaics

2017 ◽  
Author(s):  
◽  
Bradley R. Nullmeyer
Keyword(s):  
Monte Carlo ◽  
Neutron Diffraction ◽  
Diffraction Study ◽  
Pair Correlation ◽  
High Energy ◽  
Neutron Diffraction Study ◽  
Beta Radiation ◽  
Reverse Monte Carlo ◽  
Tritium Production ◽  
Alternative Materials

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] This work explores alternative materials for the improvement of radiovoltaic devices. First, lithium fluoride is explored as an effective material for generating and retaining tritium radionuclides for use in radiovoltaics. This development aims to solve a decades-old problem of inadequate tritium hosts, which have been consistently limited in their ability to retain the radioisotope and effectively deliver energy to transducing semiconductors. This new method of tritium production and retention offers new possibilities for use of what has been deemed the safest radioisotope, and offers a simple, rapid production process, which can greatly reduce cumbersome isotope loading processes associated with existing methods of fabrication for devices reliant on tritium or other radioisotopes. The primary focus of this work is the exploration of molten selenium-sulfur as a radiation-resistant semiconductor for radiovoltaic devices. Radiovoltaics have thus far been unable to utilize high energy alpha and beta radiation due to rapid performance degradation imposed by radiation damage. This work includes the exhibition of long-term power output from an alphavoltaic device fueled by 210Po. The 57+ day lifetime of this device is in great contrast to reports of conventional semiconductors, which have consistently exhibited short lifetimes. Moreover, this report details a neutron diffraction study of irradiated Se-S material, which indicates strong radiation-resistance in the liquid phase. With liquid selenium established as a promising material for radiovoltaics, this work also presents a neutron diffraction study on the material's atomic structure, which has been the subject of dispute in published literature. The neutron diffraction study is accompanied by Reverse Monte Carlo analysis, resulting in reliable conclusions regarding the overall structure near the melting point. The analysis of Reverse Monte Carlo models in comparison to experimental data identifies in the pair correlation function a key indicator of 3-fold coordinated defects which disrupt the liquid selenium structure under extreme conditions.

The intermolecular potential of methane A neutron diffraction study on low-density CD4

1997 ◽  
Vol 234-236 ◽  
pp. 353-354 ◽  
Author(s):  
E. Guarini ◽  
U. Bafile ◽  
F. Cilloco ◽  
R. Magli ◽  
F. Barocchi
Keyword(s):  
Neutron Diffraction ◽  
Diffraction Study ◽  
Neutron Diffraction Study ◽  
Intermolecular Potential ◽  
Low Density

The Pair Correlation Function of the Liquid-Vapour Interface: A Monte Carlo Calculation

1979 ◽  
Vol 34 (10) ◽  
pp. 1236-1238
Author(s):  
B. Borštnik ◽  
A. Ažman
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Correlation Function ◽  
Density Profile ◽  
Pair Correlation Function ◽  
Monte Carlo Calculation ◽  
Pair Correlation ◽  
Low Density ◽  
Density Region ◽  
New Information

Abstract A Monte Carlo simulation of the liquid-vapour interface near the triple point is reported. A monotonic density profile is obtained. In the entire interface the pair correlation function g(r) was found to be very close to the liquid bulk g(r), except for the low density region (ϱ(z)/(ϱliq ≦ 0.25 ) where information was inaccessible. The behaviour of the solution of the BGYB equation for the density profile is explored in the context of the new information concerning the pair correlation function in the interface.

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