1,814 research outputs found
Electron scattering in HCl: An improved nonlocal resonance model
We present an improved nonlocal resonance model for electron-HCl collisions. The short-range part of the model is fitted to ab initio electron-scattering eigenphase sums calculated using the Schwinger multichannel method, while the long-range part is based on the ab initio potential-energy curve of the bound anion HCl-. This model significantly improves the agreement of nonlocal resonance calculations with recent absolute experimental data on dissociative electron attachment cross sections for HCl and DCl. It also partly resolves an inconsistency in the temperature effect in dissociative electron attachment to HCl present in the literature. Finally, the present model reproduces all qualitative structures observed previously in elastic scattering and vibrational-excitation cross sections
Multiscale non-adiabatic dynamics with radiative decay, case study on the post-ionization fragmentation of rare-gas tetramers
In this supplementary material, we recollect, for reader's convenience, the
general scheme of suggested multiscale model (Sec. 1), and basic informations
about approaches used for pilot study: a detailed description of the
interaction model (Sec. 2) and dynamical methods used for the dark dynamics
step (Sec. 3) reported previously in two preceding studies [1, 2]. In addition,
a detailed description of the treatment of radiative processes is also given
(Sec. 4).Comment: supplementary material for parent paper; 9 pages, 1 figure; corrected
formulae and misleading notation in Sec.4 (pages 7 and 8
Mechanisms and dynamics of the metastable decay in Ar-2(+)
A detailed experimental as well as theoretical investigation of the properties of the metastable dissociation Ar-2(+)--\u3eAr++Ar is presented. The mass-analyzed ion kinetic energy (MIKE) scan technique has been performed using a three sector field mass spectrometer. The possible mechanisms of the metastability of Ar-2(+) have been examined and the observed decay process is assigned to the II(1/2)(u)--\u3eI(1/2)(g) bound to continuum radiative transition, in agreement with earlier work. The calculation of the theoretical shape of the kinetic energy release distribution of fragment ions allowed us to construct the theoretical MIKE peak and compare it with the raw experimental data. The accuracy of various sets of potential energy curves for Ar-2(+) is discussed, as well as the way of production of the metastable Ar-2(+)[II(1/2)(u)] electronic state by electron impact. Excellent agreement between the experimental data and theoretical model has been observed. (C) 2004 American Institute of Physics
Kinetic-energy release in Coulomb explosion of metastable C3H52+
C3H52+, formed by electron impact ionization of propane, undergoes metastable decay into C2H2++CH3+. We have monitored this reaction in a magnetic mass spectrometer of reversed geometry that is equipped with two electric sectors (BEE geometry). Three different techniques were applied to identify the fragment ions and determine the kinetic-energy release (KER) of spontaneous Coulomb explosion of C3H52+ in the second and third field free regions of the mass spectrometer. The KER distribution is very narrow, with a width of about 3% [root-mean square standard deviation]. An average KER of 4.58+/-0.15 eV is derived from the distribution. High level ab initio quantum-chemical calculations of the structure and energetics of C3H52+ are reported. The activation barrier of the reverse reaction, CH3++C2H2+ (vinylidene), is computed. The value closely agrees with the experimental average KER, thus indicating that essentially all energy available in the reaction is partitioned into kinetic energy. (C) 2003 American Institute of Physics
Extended crossover from Fermi liquid to quasi-antiferromagnet in the half-filled 2D Hubbard model
The ground state of the Hubbard model with nearest-neighbor hopping on the
square lattice at half filling is known to be that of an antiferromagnetic
(AFM) band insulator for any on-site repulsion. At finite temperature, the
absence of long-range order makes the question of how the interaction-driven
insulator is realized nontrivial. We address this problem with controlled
accuracy in the thermodynamic limit using self-energy diagrammatic determinant
Monte Carlo and dynamical cluster approximation methods and show that
development of long-range AFM correlations drives an extended crossover from
Fermi liquid to insulating behavior in the parameter regime that precludes a
metal-to-insulator transition. The intermediate crossover state is best
described as a non-Fermi liquid with a partially gapped Fermi surface.Comment: 6 pages, 4 figures, with supplemental material: 2 pages, 3 figure
A methodology for the construction of efficient PLC based low-power photovoltaic generation plants
The research of the operation of low-power photovoltaic generation plants used for self-contained electric power supply in Siberian climatic conditions is performed in this paper. It provides an analysis of the operation of individual units of an automated control system, and gives recommendations for the selection of hardware components. The article describes the operational principles, developed based on functional modules of the programmable logic controller, ensuring maximum possible use of solar energy in this continuous power supply system. The results of plant operation have been obtained, in the form of a power counter log, as well as data on the volume of solar energy produced in both overcast and in sunny weather, throughout the observation period. The article provides visual illustration of generated energy, which could be used to assess the efficiency and economic viability of the low-power photovoltaic plant. Authors would like to point out that examples of the proposed methodology for the construction of self-contained power supply systems can be found in existing industrial facilities, on which further scientific research can be based
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