Search results for "sähkömagnetismi"
showing 10 items of 12 documents
Generalized finite difference schemes with higher order Whitney forms
2021
Finite difference kind of schemes are popular in approximating wave propagation problems in finite dimensional spaces. While Yee’s original paper on the finite difference method is already from the sixties, mathematically there still remains questions which are not yet satisfactorily covered. In this paper, we address two issues of this kind. Firstly, in the literature Yee’s scheme is constructed separately for each particular type of wave problem. Here, we explicitly generalize the Yee scheme to a class of wave problems that covers at large physics field theories. For this we introduce Yee’s scheme for all problems of a class characterised on a Minkowski manifold by (i) a pair of first ord…
Observation of Poincaré-Andronov-Hopf Bifurcation in Cyclotron Maser Emission from a Magnetic Plasma Trap
2018
We report the first experimental evidence of a controlled transition from the generation of periodic bursts of electromagnetic radiation into the continuous-wave regime of a cyclotron maser formed in magnetically confined nonequilibrium plasma. The kinetic cyclotron instability of the extraordinary wave of weakly inhomogeneous magnetized plasma is driven by the anisotropic electron population resulting from electron cyclotron plasma heating in a MHD-stable minimum-B open magnetic trap. peerReviewed
The M4 transitions of isomeric states
2015
Tässä pro gradu -tutkielmassa tutkitaan isomeeristen tilojen magneettisten M4-gammasiirtymien redusoituja matriisielementtejä. Tutkittavat siirtymät ovat venyneitä M4-siirtymiä kaksoisbeetahajoamisten massa-alueilla A=85-115 ja A=135-143. Tutkielman tarkoituksena on verrata kokeellisia ydinmatriisielementtejä kvasihiukkasmatriisielementteihin ja MQPM-teorian avulla laskettuihin matriisielementteihin. Kokeelliset matriisielementi lasketaan kokeellisesti määritettyjen arvojen avulla ja kvasihiukkas- sekä MQPM-matriisielementit määritetään tietokoneohjelmien avulla. Kokeellisten ja kvasihiukkasmatriisielementtien välinen suhde osoittautui olevan noin 0,29 ja kokeellisten ja MQPM-matriisielemen…
Code for manuscript: Nonreciprocal Josephson linear response
2023
Codes related to manuscript "Nonreciprocal Josephson linear response", including the scripts that generate the figures in the manuscript. The preprint is available at https://doi.org/10.48550/arXiv.2306.12295 This is a snapshot of the code dataset that has been taken on 06.07.2023. A more detailed description of the data and the address to the GitLab repository for the latest version of the code can be found from the parent dataset of this data publication.
Nonreciprocal Josephson linear response (parent repository)
2023
The repository contains computer codes related to manuscript "Nonreciprocal Josephson linear response", including the scripts that generate the figures in the manuscript. The preprint is available at https://doi.org/10.48550/arXiv.2306.12295 This is the metadata for the parent repository of the codes. Updates and possible corrections are documented in the GitLab project, where the material saved and shared. The GitLab project can be found and downloaded from the following address: https://gitlab.jyu.fi/jyucmt/2023-nonreciprocal-josephson
Electromagnetic scattering solutions for digital signal processing
2010
Effect of molecular Stokes shift on polariton dynamics
2021
When the enhanced electromagnetic field of a confined light mode interacts with photoactive molecules, the system can be driven into the regime of strong coupling, where new hybrid light–matter states, polaritons, are formed. Polaritons, manifested by the Rabi split in the dispersion, have shown potential for controlling the chemistry of the coupled molecules. Here, we show by angle-resolved steady-state experiments accompanied by multi-scale molecular dynamics simulations that the molecular Stokes shift plays a significant role in the relaxation of polaritons formed by organic molecules embedded in a polymer matrix within metallic Fabry–Pérot cavities. Our results suggest that in the case …
Generalized wave propagation problems and discrete exterior calculus
2018
We introduce a general class of second-order boundary value problems unifying application areas such as acoustics, electromagnetism, elastodynamics, quantum mechanics, and so on, into a single framework. This also enables us to solve wave propagation problems very efficiently with a single software system. The solution method precisely follows the conservation laws in finite-dimensional systems, whereas the constitutive relations are imposed approximately. We employ discrete exterior calculus for the spatial discretization, use natural crystal structures for three-dimensional meshing, and derive a “discrete Hodge” adapted to harmonic wave. The numerical experiments indicate that the cumulat…
Sähkömagneettisen sironnan numeerinen simulointi
2004
The nonstationary Maxwell system in domains with edges and conical points
2005
Sergey Matyukevich on väitöskirjassaan tutkinut Maxwell-yhtälöä alueilla, joilla on kartiomaisia kärkiä ja teräviä särmiä. Erityisen huomion kohteena tutkimuksessa oli tutkia yhtälön ratkaisujen käyttäytymistä lähellä ns. singulaaripisteitä, joita epäsileät reunat aiheuttavat. Tutkimuksessa Matyukevich on johtanut ratkaisuille eksplisiittisiä, asymptoottisia laajennuksia alueen kartiomaisten kärkien ja terävien särmien ympäristössä.Tutkimuksen tuloksilla on merkitystä siinä, että niitä voidaan soveltaa useiden ei-stationaaristen sähkömagnetiikan yhtälöiden matemaattisessa ja numeerisessa analysoinnissa epäsileillä alueilla. We study the nonstationary Maxwell system in domains with conical p…