Radiation Heat Generation Research Articles

Retraction: Anomalous Doppler-effect singularities in radiative heat generation, interaction forces, and frictional torque for two rotating nanoparticles [Phys. Rev. A 96 , 012520 (2017)

Received 23 December 2019Accepted 24 December 2019DOI:https://doi.org/10.1103/PhysRevA.101.029901©2020 American Physical SocietyPhysics Subject Headings (PhySH)Research AreasCasimir effect & related phenomenaGeneral PhysicsBiological PhysicsAtomic, Molecular & Optical

Resonant photon emission during relative sliding of two dielectric plates

The effect of resonances in the photon emission rate in radiative heat generation and transfer, and Casimir friction at the relative sliding of two plates of polar dielectrics is studied. Resonances are of a different origin in the frequency range of the normal (NED) and anomalous (AED) Doppler effect. In the NED domain, resonances are associated with resonant photon tunneling between surface phonon/plasmon polaritons. In the AED domain resonances are associated with the instantaneous generation of excitations in both plates. While in the NED domain the resonances are finite, in the ADE domain singular resonances are possible even in the presence of dissipation in the system.

Effect of Resonant Photon Emission in Radiative Heat Transfer and Generation

The effect of resonances in the photon emission rate in the radiative heat generation and transfer and the Casimir friction at the sliding of two polar dielectric plates has been studied. The resonances have different origin in the frequency ranges of the normal and anomalous Doppler effects. In the frequency range of the normal Doppler effect, the resonances are due to resonant photon tunneling between surface phonon/plas-mon polaritons of plates. Such resonances exist only at a relative sliding velocity v = 0 for two identical plates. However, the resonances may occur at v ≠ 0 for different plates. In the frequency range of the anomalous Doppler effect, the resonances are due to the excitation generation in both plates. While the resonances are finite in the frequency range of the normal Doppler effect, singular resonances are possible even in the presence of dissipation in the system in the frequency range of the anomalous Doppler effect. The resonances for identical and different sliding plates have been considered.

RETRACTED ARTICLE: Singular Resonance in Fluctuation-Induced Electromagnetic Phenomena at the Rotation of a Nanoparticle near the Surface of a Condensed Medium

It is shown that in fluctuation-electromagnetic phenomena (Casimir force, Casimir friction, radiative heat generation) for a spherical nanoparticle with a radius $R$ rotating near a surface a singular resonance can occur, near which fluctuation-electromagnetic effects are strongly enhanced even in the presence of dissipation in the system. The resonance takes place at the particle-surface separation $ d <d_0= R[3/4\varepsilon_1''(\omega_1)\varepsilon_2''(\omega_2)]^{1/3}$ (where $\varepsilon_i''(\omega_i)$ is the imaginary part of the dielectric function of a particle or a medium at the surface plasmon or phonon polariton frequency $\omega_i$), when the rotation frequency $\Omega$ coincides with the poles in the photon generation rate at $\Omega\approx \omega_1 + \omega_2$. These poles arise due to the multiple scattering of electromagnetic waves between the particle and the surface under the conditions of the anomalous Doppler effect and they exist even in the presence of dissipation. For $ d <d_0$ in the dependence on the particle rotation frequency the Casimir force can change sign, i.e. the attraction of the particle to the surface is replaced by the repulsion. The obtained results can be important for nanotechnology.

Singular resonance in fluctuation-electromagnetic phenomena during the rotation of a nanoparticle near a surface

It is shown that in fluctuation-electromagnetic phenomena (Casimir force, Casimir friction, radiative heat generation) for a spherical nanoparticle with a radius R rotating near a surface a singular resonance can occur, near which fluctuation-electromagnetic effects are strongly enhanced even in the presence of dissipation in the system. The resonance takes place at the particle-surface separation (where is the imaginary part of the dielectric function of a particle or a medium at the surface plasmon or phonon polariton frequency ), when the rotation frequency Ω coincides with the poles in the photon generation rate at . These poles arise due to the multiple scattering of electromagnetic waves between the particle and the surface under the conditions of the anomalous Doppler effect and they exist even in the presence of dissipation. For d < d0 in the dependence on the particle rotation frequency the Casimir force can change sign, i.e., the attraction of the particle to the surface is replaced by the repulsion. The obtained results can be important for nanotechnology.

Anomalous Doppler-effect singularities in radiative heat generation, interaction forces, and frictional torque for two rotating nanoparticles

We calculate the quantum heat generation, the interaction force and the frictional torque for two rotating spherical nanoparticles with a radius $R$. In contrast to the static case, when there is an upper limit in the radiative heat transfer between the particles, for two rotating nanoparticles the quantum heat generation rate diverges when the angular velocity becomes equal to the poles in the photon emission rate. These poles arise for the separation $d <d_0= R(3/\varepsilon''(\omega_0))^{1/3}$ (where $\varepsilon''(\omega_0)$ is the imaginary part of the dielectric function for the particle material at the surface phonon or plasmon polariton frequency $\omega_0$ ) due to the anomalous Doppler effect and the mutual polarization of the particles and they exist even for the particles with losses. Similar singularities exist also for the interaction force and the frictional torque. The obtained results can be important for biomedical applications.

Singularities in radiative heat generation and interaction forces for two rotating nanoparticles caused by the anomalous Doppler effect

The quantum heat generation, interaction force, and friction torque for two rotating spherical nanoparticles with the radius R are calculated. In contrast to a static case where an upper bound in the radiative heat transfer between two particles exists, the quantum heat generation for two rotating particles diverges at distances between particles d < d 0 = R(3/e″(ω0))1/3 (where e″(ω0) is the imaginary part of the dielectric function for the material of a particle at the resonance frequency ω0), when the rotation frequency coincides with poles in the excitation generation rate at Ω = 2ω0. These poles are due to the anomalous Doppler effect and the mutual polarization of particles and exist even in the presence of dissipation in particles. The anomalous heat generation is associated with the conversion of mechanical rotation energy into heat mediated by quantum friction. Similar singularities also exist for the interaction force and friction torque. The results can be of significant importance for biomedical applications.

Improved method for calculating the radiation heat generation in the BOR-60 reactor

The results of theoretical and experimental studies aimed at determining the radiation heat generation in the BOR-60 reactor reveal the drawbacks of the computational methods used at present. An algorithm that is free from these drawbacks and allows one to determine the radiation heat generation computationally is proposed.

Testing the improved method for calculating the radiation heat generation at the periphery of the BOR-60 reactor core

The application of the improved method for calculating the radiation heat generation in the elements of an experimental device located at the periphery of the BOR-60 reactor core results in a significant reduction in the discrepancies between the calculated and the experimental data. This allows us to conclude that the improved method has an advantage over the one used earlier.

Performance of Canopy Hood and Radiative Heat Generation from Low-Radiation Cooking Equipment with Concentrated Exhaust Chimney

Performance of Canopy Hood and Radiative Heat Generation from Low-Radiation Cooking Equipment with Concentrated Exhaust Chimney

Radiation stability of prototype ITER-type resistive bolometers with improved electrical contacts

We present the results for reactor irradiation of prototype ITER-compatible resistive radiation hardened bolometers up to a total dose of ∼0.01 dpa (thermal/fast [ E > 0.1 MeV] neutron fluence of 5.2/0.8 ×10 19 n/cm 2). The prototype bolometer has a 100 nm thick Pt meander deposited on an alumina ceramic substrate. Connection of the delicate meander with external wiring is provided via special binding posts placed on the substrate. The binding post consist of a Pt ring attached to the substrate using melted glass, with a laser welded 0.1 mm diameter Pt wire. A vacuum capsule with a special bolometer holder was designed and fabricated to allow reactor irradiation at ∼400 °C in vacuum. The desired temperature was obtained by balancing the radiation heat generation and thermal energy losses via radiation and conductive heat transfer. The resistance of the Pt meander was measured in the course of 19 days irradiation in the BR2 material testing reactor of the SCK·CEN. Immediately after insertion of the bolometer into the reactor a significant decrease of the meander resistance was observed. The resistance then stabilized after several days of irradiation. The meander resistance measurements were stable during the first week of irradiation, but then the electrical contact was lost. Post-irradiation inspection showed that the binding posts remained attached to the substrate while one of the Pt wires detached from the Pt ring most probably due to a bad laser weld.

Nonuniform swelling and hydrogen redistribution in zirconium hydride under neutron irradiation

Swelling, hydride composition, distributions of microhardness and thermoelectric power in cross sections of zirconium hydride samples irradiated in the BN-600 reactor with neutron fluence of ∼6.0 · 10 26 n⧸m 2 ( E > 0) in the temperature range of 670–770 K have been investigated. A correlation of microhardness increment and swelling has been established. Swelling in outer layers of materials turned out to be twice of that in inner ones. This fact is due to variations of neutron flux and energy release—radiation heat generation in a bulk of zirconium hydride under fission gamma ray and neutron irradiations.

A comparison on the stability of horizontal fluid layers with radiative heat generation for two and three porous plates

A comparison on the stability of horizontal fluid layers with radiative heat generation for two and three porous plates

The onset of convection in free surface fluid layers with radiative heat generation

The onset of convection in free surface fluid layers with radiative heat generation

The onset of convection in free surface fluid layers with radiative heat generation

The onset of convection in free surface fluid layers with radiative heat generation