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2022 ◽  
Author(s):  
Matej Kurtulik ◽  
Michal Shimanovich ◽  
Rafi Weill ◽  
Assaf Manor ◽  
Michael Shustov ◽  
...  

Abstract Planck’s law of thermal radiation depends on the temperature, \(T\), and the emissivity, \(\epsilon\), which is the coupling of heat to radiation depending on both phonon-electron nonradiative-interactions and electron-photon radiative-interactions. In contrast, absorptivity, \(\alpha\), only depends on the electron-photon radiative-interactions. At thermodynamic equilibrium, nonradiative-interactions are balanced, resulting in Kirchhoff’s law of thermal radiation, \(\epsilon =\alpha\). For non-equilibrium, Quantum efficiency (QE) describes the statistics of photon emission, which like emissivity depends on both radiative and nonradiative interactions. Past generalized Planck’s equation extends Kirchhoff’s law out of equilibrium by scaling the emissivity with the pump-dependent chemical-potential \(\mu\), obscuring the relations between the body properties. Here we theoretically and experimentally demonstrate a prime equation relating these properties in the form of \(\epsilon =\alpha \left(1-QE\right)\). At equilibrium, these relations are reduced to Kirchhoff’s law. Our work lays out the evolution of non-thermal emission with temperature, which is critical for the development of lighting and energy devices.


2021 ◽  
Vol 9 ◽  
Author(s):  
Makoto Asai ◽  
Miguel A. Cortés-Giraldo ◽  
Vicent Giménez-Alventosa ◽  
Vicent Giménez Gómez ◽  
Francesc Salvat

A translation of the penelope physics subroutines to C++, designed as an extension of the Geant4 toolkit, is presented. The Fortran code system penelope performs Monte Carlo simulation of coupled electron-photon transport in arbitrary materials for a wide energy range, nominally from 50 eV up to 1 GeV. Penelope implements the most reliable interaction models that are currently available, limited only by the required generality of the code. In addition, the transport of electrons and positrons is simulated by means of an elaborate class II scheme in which hard interactions (involving deflection angles or energy transfers larger than pre-defined cutoffs) are simulated from the associated restricted differential cross sections. After a brief description of the interaction models adopted for photons and electrons/positrons, we describe the details of the class-II algorithm used for tracking electrons and positrons. The C++ classes are adapted to the specific code structure of Geant4. They provide a complete description of the interactions and transport mechanics of electrons/positrons and photons in arbitrary materials, which can be activated from the G4ProcessManager to produce simulation results equivalent to those from the original penelope programs. The combined code, named PenG4, benefits from the multi-threading capabilities and advanced geometry and statistical tools of Geant4.


2021 ◽  
Vol 24 (4) ◽  
pp. 317-325
Author(s):  
I. A. Shershan ◽  
T. V. Shishkina

Differential and total cross sections of single gauge boson production in high energy electron-photon collisions obtained within the Standard Model in leading order and next-to-leading order are presented. Soft photon bremsstrahlung as well as hard photon bremsstrahlung parts were considered using the dimensional regularization procedure. Special features of receiving the hard bremsstrahlung convergent contribution are discussed. The corresponding anomalous gauge boson couplings were studied in the effective Lagrangian approach. Best conditions for registration of effects beyond the Standard Model are determined.


Author(s):  
Matteo Villani ◽  
Xavier Oriols

AbstractTo avoid the computational burden of many-body quantum simulation, the interaction of an electron with a photon (phonon) is typically accounted for by disregarding the explicit simulation of the photon (phonon) degree of freedom and just modeling its effect on the electron dynamics. For quantum models developed from the (reduced) density matrix or its Wigner–Weyl transformation, the modeling of collisions may violate complete positivity (precluding the typical probabilistic interpretation). In this paper, we show that such quantum transport models can also strongly violate the energy conservation in the electron–photon (electron–phonon) interactions. After comparing collisions models to exact results for an electron interacting with a photon, we conclude that there is no fundamental restriction that prevents a collision model developed within the (reduced) density matrix or Wigner formalisms to satisfy simultaneously complete positivity and energy conservation. However, at the practical level, the development of such satisfactory collision model seems very complicated. Collision models with an explicit knowledge of the microscopic state ascribed to each electron seems recommendable (Bohmian conditional wavefunction), since they allow to model collisions of each electron individually in a controlled way satisfying both complete positivity and energy conservation.


2021 ◽  
Author(s):  
Jing Zhang

Abstract The fast and slow fading of radio signal transmissions or laser beam itself and its spare light confirm the presence of two kinds of collisions --- electron-photon and photon-photon collision. Photon transmissions of radio signals are either consecutive dense photon groups in slow fading process or widespread group pattern in fast fading form. The photon transmission shapes are irregular and dynamical changes. The radio frequency shift and the wavelength reduction by the calculation demonstrate decelerations of radio/light transmission speeds due to the gradual reduced distance between two consecutive photon groups along the transmission pathway. Photons from radio signals are able to affect electron movements in radio signal receiving process and electrons able to kick photons into space during radio signal emission. The pattern of free electron movement under the influence of local electromagnetic force in antenna is consistent with the randomly dynamic changes of radio signal in space. The fast fading is due to the collision of consecutive photon groups of signals in slow fading with free photons in space. The shape changes of radio signal peaks suggest photons able to remain in transmission photon groups after photon-photon collision, leading to deceleration transmissions in slow fading. The mathematical equation for the relationship between light/radio transmission speeds before and after photons collisions is established. The equation is confirmed by the calculations of well-known difference of light transmission speeds in different media. The gravities from Earth and Sun play little role during light/radio transmission.


2021 ◽  
Vol 104 (11) ◽  
Author(s):  
J. Kevin Nangoi ◽  
Siddharth Karkare ◽  
Ravishankar Sundararaman ◽  
Howard A. Padmore ◽  
Tomás A. Arias

Atoms ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 67
Author(s):  
Imane Ajana ◽  
Driss Nehari ◽  
Driss Khalil ◽  
Abdelmalek Taoutioui ◽  
Hicham Agueny ◽  
...  

We report on a joined experimental and theoretical study of differential cross-sections resulting from inelastic scattering of a monoenergetic electron by helium atoms in the presence of an intense carbon dioxide laser. In particular, we measured the signals of the scattered electrons during the simultaneous electron–photon excitation of He 21P state for the first three microseconds of the laser pulse. The signals were measured for an incident electron energy of 45 eV and showed a structure that emerged at small scattering angles. The latter was found to be sensitive to the nature of the transferred photons, as well as the intensity of the laser field. The experimental findings were supported by quantum calculations based on the second-order Born approximation in which the correlated electron–electron interactions were taken into account.


2021 ◽  
Vol 75 (3) ◽  
pp. 64-69
Author(s):  
К.М. Mukashev ◽  
◽  
A.V. Stepanov ◽  
T.Kh. Sadykov ◽  
A. К. Argynova ◽  
...  

At present, at the high-mountain scientific station for the study of the physics of cosmic rays, various, independently operating unique experimental installations are used. The article discusses the ways and methods of combining these installations into a single system, which includes networks of scintillation detectors of the "carpet" type for registration of the electron-photon component, ground and underground monitors for registration of neutron components, calorimeters, Cherenkov detectors, a scintillation spectrometer and a number of other subsystems. The newly created unified system for registering cosmic rays based on the achievements of modern technology and scientific thought will have a high resolution, with a common databank with synchronization in time of operation of separate, independently operating experimental installations. The solution to this problem will make it possible to perform a detailed analysis of the recorded events from a single position, to carry out complex calculations of the spatial distribution, mass composition, and also the energy structure of cosmic rays with a high degree of accuracy.


2021 ◽  
Author(s):  
Jing Zhang

Abstract The fast and slow fading of radio signal transmissions or laser beam itself and its spare light confirm the presence of two kinds of collisions --- electron-photon and photon-photon collision. Photon transmissions of radio signals are either consecutive dense photon groups in slow fading process or widespread group pattern in fast fading form. The photon transmission shapes are irregular and dynamical changes. The radio frequency shift and the wavelength reduction by the calculation demonstrate decelerations of radio/light transmission speeds due to the gradual reduced distance between two consecutive photon groups along the transmission pathway. Photons from radio signals are able to affect electron movements in radio signal receiving process and electrons able to kick photons into space during radio signal emission. The pattern of free electron movement under the influence of local electromagnetic force in antenna is consistent with the randomly dynamic changes of radio signal in space. The fast fading is due to the collision of consecutive photon groups of signals in slow fading with free photons in space. The shape changes of radio signal peaks suggest photons able to remain in transmission photon groups after photon-photon collision, leading to deceleration transmissions in slow fading. The mathematical equation for the relationship between light/radio transmission speeds before and after photons collisions is established. The equation is confirmed by the calculations of well-known difference of light transmission speeds in different media. The gravities from Earth and Sun play little role during light/radio transmission.


2021 ◽  
Author(s):  
Jing Zhang

Abstract The fast and slow fading of radio signal transmissions or laser beam itself and its spare light confirm the presence of two kinds of collisions --- electron-photon and photon-photon collision. Photon transmissions of radio signals are either in consecutive dense photon groups in slow fading process or widespread group pattern in fast fading form. The photon transmission shapes are irregular and dynamical changes. The radio frequency shift and the wavelength reduction by the calculation demonstrate decelerations of radio/light transmission speeds due to the gradual reduced distance between two consecutive photon groups along the transmission pathway. Photons from radio signals are able to affect electron movements in radio signal receiving process and electrons able to kick photons into space during radio signal emission. The pattern of free electron movement under the influence of local electromagnetic force in antenna is consistent with the randomly dynamic changes of radio signal in space. The fast fading is due to the collision of consecutive photon groups of signals in slow fading with free photons in space. The shape changes of radio signal peaks suggest photons able to remain in transmission photon groups after photon-photon collision, leading to deceleration transmissions in slow fading. The mathematical equation for the relationship between light/radio transmission speeds before and after photons collisions is established. The equation is confirmed by the calculations of well-known difference of light transmission speeds in different media. The gravities from Earth and Sun play little role during light/radio transmission.


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