A self-consistent investigation of Smith–Purcell radiation from a narrow tape helix

1969 ◽  
Vol 47 (4) ◽  
pp. 435-449 ◽  
Author(s):  
A. R. Neureuther ◽  
R. Mittra
Keyword(s):  
Electron Beam ◽  
Source Model ◽  
Order Effects ◽  
Determinantal Equation ◽  
Confined Flow ◽  
Self Consistent ◽  
Wave Numbers ◽  
Traveling Wave Tubes ◽  
Complex Waves

The interaction of a modulated electron beam and a narrow tape helix is considered using a confined flow model for the beam. With this model, the analysis is self-consistent in that it takes into account the first-order effects of the interaction on the beam. The interaction is studied by means of complex waves on the composite system of the beam and the helix. The role of these waves is established in part on the basis of their complex wave numbers which are solutions of the appropriate determinantal equation. Although coupling similar to that used in traveling wave tubes is considered initially, the investigation concentrates on coupling which can be used to produce Smith–Purcell radiation. The results of the numerical evaluation of the wave numbers demonstrate that for the latter type of coupling, the modulation changes very slowly along the length of the interaction. This establishes the heretofore questionable validity of the prescribed source model for evaluating the interaction of a modulated electron beam and a narrow tape helix. Similar results are expected to hold for other interaction geometries.

scholarly journals Tabulated square-shaped source model for linear accelerator electron beam simulation

2017 ◽  
Vol 13 (1) ◽  
pp. 69 ◽  
Author(s):  
Ahmad Ameri ◽  
Navid Khaledi ◽  
MahmoodReza Aghamiri ◽  
Hossein Aslian
Keyword(s):  
Electron Beam ◽  
Linear Accelerator ◽  
Source Model

scholarly journals Chemical insights into the electronic structure of Fe(II) porphyrin using FCIQMC, DMRG, and generalized active spaces

2020 ◽  
Author(s):  
Oskar Weser ◽  
Leon Freitag ◽  
Kai Guther ◽  
Ali Alavi ◽  
Giovanni Li Manni
Keyword(s):  
Electron Correlation ◽  
Quantitative Measure ◽  
Model System ◽  
Quintet State ◽  
Consistent Field ◽  
Self Consistent ◽  
Stabilizing Effect ◽  
Self Consistent Field ◽  
Preliminary Version

<div>Stochastic-CASSCF and DMRG procedures have been utilized to quantify the role of the electron correlation mechanisms that in a Fe-porphyrin model system are responsible for the differential stabilization of the triplet over the quintet state. Orbital entanglement diagrams and CI-coefficients of the wave function in a localised orbital basis allow for an effective interpretation of the role of charge-transfer configurations. A preliminary version of the <i>Stochastic Generalized Active Space Self-Consistent Field</i> method has been developed and is here introduced to further assess the pi-backdonation stabilizing effect.</div><div>By the new method excitations between metal and ligand orbitals can selectively be removed from the complete CI expansion. It is demonstrated that these excitations are key to the differential stabilization of the triplet, effectively leading to a quantitative measure of the correlation enhanced pi-backdonation.</div><div><br></div>

scholarly journals Self-consistent determination of spin Hall angle and spin diffusion length in Pt and Pd: The role of the interface spin loss

2018 ◽  
Vol 4 (6) ◽  
pp. eaat1670 ◽  
Author(s):  
Xinde Tao ◽  
Qi Liu ◽  
Bingfeng Miao ◽  
Rui Yu ◽  
Zheng Feng ◽  
...  
Keyword(s):  
Spin Diffusion ◽  
Diffusion Length ◽  
Self Consistent ◽  
Hall Angle ◽  
Spin Diffusion Length

scholarly journals The Enigma of the Muon and Tau Solved by Emergent Quantum Mechanics?

2019 ◽  
Vol 9 (7) ◽  
pp. 1471
Author(s):  
Theo van Holten
Keyword(s):  
Quantum Mechanics ◽  
Droplet Model ◽  
Matter Waves ◽  
Equilibrium Configurations ◽  
Self Consistent ◽  
Usual Quantum ◽  
Electron Models ◽  
Charged Leptons ◽  
Emergent Quantum Mechanics

This paper addresses the long-standing question of how it may be explained that the three charged leptons (the electron, muon and tau particle) have different masses, despite their conformity in other respects. In the field of Emergent Quantum Mechanics non-singular electron models are being revisited, and from this exploration has come a possible answer. In this paper a deformable droplet model is considered. It is shown how the model can be made self-consistent, whilst obeying the laws of momentum and energy conservation as well as Larmor’s radiation law. The droplet appears to have three different static equilibrium configurations, each with a different mass. Tentatively, these three equilibrium masses were assumed to correspond with the measured masses of the charged leptons. The droplet model was tuned accordingly, and was thereby completely quantified. The dynamics of the droplet then showed a “De Broglie-like” relation p = K / λ . Beat patterns in the vibrations of the droplet play the role of the matter waves of usual quantum mechanics. The value of K , calculated by the droplet theory, practically equals Planck’s constant: K ≅ h . This fact seems to confirm the correctness of identifying the three types of charged leptons with the equilibria of a droplet of charge.

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