isotropic radiation
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Author(s):  
Dong‐Su Choi ◽  
Yoon‐Seon Choi ◽  
Dae‐Keun Ju ◽  
Bang Chul Jung ◽  
Jong‐Myung Woo

2021 ◽  
Author(s):  
Said Mikki

We investigate a new type of electromagnetic meta-materials (MTMs), which we dub Proca MTMs, constituting an interesting medium behaving like a “relativistic material” for potential use in electromagnetic applications. It is rigorously proved using a field-theoretic approach that Maxwell theory inside certain classes of nonlocal metamaterials is equivalent to Maxwell-Proca theory in vacuum, where in the latter photons acquire a nonzero mass (massive electromagnetism.) It turns out that the key to the operation of Proca MTM is nonlocality (here spatial dispersion since the Proca MTM is homogeneous), and hence Proca MTMs represent an important example of the more general family of nonlocal MTMs. Our analysis involves multiphysics aspects, utilizing concepts and methods taken from classical electromagnetism, special relativity, quantum theory, electromagnetic materials, and antenna theory. Extensive discussion of the physics, computational methods, and design parameters of Proca MTMs is provided to further understand the nature of massive electromagnetism in nonlocal MTMs. Proca waves carry an additional polarization degree of freedom and each wave appears to behave like a single mode with two transverse components and one longitudinal. This opens the door for applications in wireless communications and other fields where information could be encoded in polarization. As a concrete application, we develop the main ingredients of Proca antennas as an example of the emerging technology of nonlocal antennas, where we establish that a single Proca dipole possesses a perfect isotropic radiation pattern, a radical departure from conventional local antennas (radiators in vacuum and temporally dispersive media) where such radiation characteristics is impossible. Moreover, the new connection between electromagnetic theory in some nonlocal MTMs and Maxwell-Proca theory allows the use of relativistic techniques developed in the latter in order to efficiently perform calculations like field quantization in nonlocal domains which would be very difficult to perform otherwise.


2021 ◽  
Author(s):  
Said Mikki

We investigate a new type of electromagnetic meta-materials (MTMs), which we dub Proca MTMs, constituting an interesting medium behaving like a “relativistic material” for potential use in electromagnetic applications. It is rigorously proved using a field-theoretic approach that Maxwell theory inside certain classes of nonlocal metamaterials is equivalent to Maxwell-Proca theory in vacuum, where in the latter photons acquire a nonzero mass (massive electromagnetism.) It turns out that the key to the operation of Proca MTM is nonlocality (here spatial dispersion since the Proca MTM is homogeneous), and hence Proca MTMs represent an important example of the more general family of nonlocal MTMs. Our analysis involves multiphysics aspects, utilizing concepts and methods taken from classical electromagnetism, special relativity, quantum theory, electromagnetic materials, and antenna theory. Extensive discussion of the physics, computational methods, and design parameters of Proca MTMs is provided to further understand the nature of massive electromagnetism in nonlocal MTMs. Proca waves carry an additional polarization degree of freedom and each wave appears to behave like a single mode with two transverse components and one longitudinal. This opens the door for applications in wireless communications and other fields where information could be encoded in polarization. As a concrete application, we develop the main ingredients of Proca antennas as an example of the emerging technology of nonlocal antennas, where we establish that a single Proca dipole possesses a perfect isotropic radiation pattern, a radical departure from conventional local antennas (radiators in vacuum and temporally dispersive media) where such radiation characteristics is impossible. Moreover, the new connection between electromagnetic theory in some nonlocal MTMs and Maxwell-Proca theory allows the use of relativistic techniques developed in the latter in order to efficiently perform calculations like field quantization in nonlocal domains which would be very difficult to perform otherwise.


Author(s):  
A.V. Kolesnikov ◽  
P.F. Pronina ◽  
A.V. Paleshkin

In order to mathematically simulate the thermal effect that radiation emitted by planets has on spacecraft, two intensity field models describing planetary radiation may be used depending on the emitter specifics: isotropic and anisotropic. The isotropic model is based on the assumption that the local surface density of outgoing radiation flux is the same for all surface regions visible from orbit. In the case of the anisotropic model this value is assumed to be proportional to the zenith angle cosine for each surface element on the side of the planet that is illuminated by the Sun. Published results of studies concerning developing planetary radiation field simulators indicate that thermal vacuum installations where the working volume is comparable to the total installation volume can only reproduce the sotropic planetary radiation intensity field model. It is a pressing issue to determine whether and when it is possible to replace the anisotropic model with an isotropic one when physically simulating the effect that the solar radiation reflected from a planet and intrinsic radiation flows generated by planets with no atmosphere have on spacecraft. The investigation that we conducted regarding this issue was based on comparing the results of computing the irradiance of spacecraft elements using the models under consideration. These computation results allowed us to conclude that it is possible to physically simulate the effect of solar radiation flows reflected from planets combined with intrinsic (infrared) radiation flows generated by planets with no atmosphere by means of using simulators reproducing isotropic radiation fields in their working volumes


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