Is it possible to trap a resonance structure

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Resonance structure in weakly absorbing spheres Brett A. Resonances and poles of weakly absorbing spheres Gorden Videen, J. Observation of suppression of morphology-dependent resonances in singly levitated micrometer-sized droplets M.

Already have an account? Log in. It is not possible to trap a resonance structure for study as the resonance structures does not represent the actual structure of the molecule. We use resonance structures to represent molecules which cannot be represented by a single Lewis structure, they are not the actual representation of the molecules. And in the case of resonance, if, for instance, we were to take 03 it would look something like this, which is one resident structure.

But this double bond can move back and forth so we could also dry like this. We have to understand that neither of the's resident structures is truly showing what the electrons look like.

It's simply a way of accounting for electrons in a given molecule, so when we analyze this molecule, it wouldn't look like either of these structures. Instead, the electrons would be in a sort of cloud around the entire molecule.

But the structure helps us to understand how many electrons are in a given molecule and what kind of bonding could be present. What is a resonance structure? Is it possible to isolate one resonance struc… Can molecules with more than one central atom have resonance forms? Explain … Do resonance structures always contribute equally to the overall structure o… Do resonance structures always contribute equally to the overall structure… The coordinate superparticle image is not of the classical particle but represents a finite-sized cloud of electrons and ions which remain in the cloud at each simulation time step n.

The cloud shape function is taken cubic, with the dimensions equal to the cell sizes. The difference between the electron and the ion mobilities results in generating the self-consistent electrostatic field which changes at each time step.

Because the computational mesh is periodical, the fast Fourier transform FFT method is accepted for Poisson equation solving [ 18 ]. The FFT method permits to replace eq. Beginning with the calculated amplitudes, the mesh node electric potentials determine the self-consistent electric field through the finite-difference derivatives:. The other field components are found in the same manner. The selfconsistent field in the cloud center mass is found out beginning with the node values through the bilinear interpolation scheme generalized for 3D case.

The time evolution of the electron and ion motions are described by the Newton-Lorentz equation which in a finite difference dimensionless form is. Equation 3 for the electrons is considered relativistic not only because the electrons can acquire a high energy in the resonance conditions but also due to the exceptional sensitivity of the ECR interaction to phase the difference between the electric field and the particle velocity. As for the ions, they cannot participate in interaction with the microwaves in any point of the trap, which permits to treat eq.

The calculation programs applied in this work are exactly the same which are used in [ 13 ] for the computer simulation of an ECR minimum-B trap plasma. Equation 3 is integrated by using the second order explicit Boris leapfrog technique which is very efficient for many particle problems [ 16 ]. The problem solution procedure is the self-consistent since eqs.

Thus, the problem to be solved is the motion of electrons and ions in applied magnetic and microwave fields and their own electric field. For simulations, the total number of the real particles is divided into 4. The chosen amount of the superparticles guarantees that at least 10 of them reside in the core zone cells.

The elaborated algorithm permits to visualize the plasma space configuration and the energy distribution function at every time step as well as the plasma space shape. The simulations show that the principle parameters, like the space plasma distribution and the electron energy distribution function, come to a steady-state after 1x10 6 time steps for the minimum-B trap and after 5x10 6 time steps for the zero-B trap.

In the steady state, the longitudinal and radial ion density distributions, shown in Figs. In the corona zone, outside the ECR surface, both trap densities do not differ very much. The ion density distributions for both traps principally coincide with the electron ones see Figs. The elevated density in the centre of the both traps is directly related to the ECR interaction: the electrons which are accelerated in the vicinity of the closed ECR surface acquire large magnetic moments and consequently are pushed by the diamagnetic force to the trap centers; the higher magnetic gradient in the zero-B trap caused better plasma confinement efficiency.

A larger core volume and higher core plasma density in the zero-B trap result in that the total number of ions captured inside the ECR surface for the zero-B trap is 3. Figures 7 and 8 show the pictorial renditions of ion and electron component localizations in the zero-B longitudinal plane layer of 0. In these figures the transverse axis scale is enlarged in order some structure details to be elucidated.

These space distributions evidence that the plasma run into some problems with crossing the transverse median plane of the zero-B trap; such difficulties do not occur in the minimum-B trap. Outside the core zone, the ions are located predominantly along the chamber axis forming something like a cylinder of 0.

Such geometry of the ion space distribution suggests that the density of the ion flux which incidents on the center of a chamber end-wall is significantly higher than the density of the ion fluxes which fall on any other part of the inner wall surface. In this regard the zero-B trap looks like the minimum-B trap. Figure 9 , where the ion component distribution in the median transversal layer of 0.

The coexistence of distinct electron groups, each being determined by its proper effective temperature is a specific property of the ECR plasmas. The electron energy spectrum of two zero-B groups is displayed in a semi-logarithm scale in Fig.

The bulk electrons whose effective temperature is of 1. The hot electrons characterized by effective temperature of 6 keV are predominately found captured in the core zone limited by the ECR surface. For the core zones, the relative number of electrons with energies over 1 keV has proved to be smaller for the zero-B trap than for the minimum-B trap see Fig. The significant difference in the areas under these curves is accounted for the fact that in the ECR zero-B core zone are found confined vastly more particles than in the ECR minimum-B core zone.

For the zero-B trap some improvement in the electron heating efficiency can be achieved by decreasing the magnetic gradient in the ECR zones. It is found also the superhot fraction with energies higher than 50 keV. Previous Article Next Article.

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